Previous changes

August 2024 — minor update. Adverse effects of co-amoxiclav updated in line with manufacturer's SPC.

June 2024 — minor update. The recommendation on management of people with suspected inguinal hernia who do not need emergency hospital admission has been clarified.

March 2024 — minor update. Information on the use of fluoroquinolones was added to the ofloxacin and levofloxacin prescribing sections in line with a review published by the MHRA. Adverse effects of doxycycline updated in line with the manufacturer's SPC.

February 2024 — minor update. A link has been added to the NHS England Decision support tool: making a decision about inguinal hernia.

January 2024 — minor update. Information on the use of fluoroquinolones and reporting adverse reactions was added in line with the Drug Safety Update published by the MHRA.

May 2023 — minor update. Added potential adverse effects of co-amoxiclav to include Kounis syndrome (an allergic reaction which can result in myocardial infarction), aseptic meningitis, linear IgA disease (renal deposition of IgA), and drug-induced enterocolitis syndrome (all of unknown frequency). These adverse effects were noted in an update to the manufacturer’s summary of product characteristics.

January 2022 — reviewed. A literature search was conducted in December 2021 to identify evidence-based guidelines, UK policy, systematic reviews, and key randomized controlled trials published since the last revision of the topic. Some minor structural changes have been made to the topic. The recommendations on assessment and management have been updated in line with current evidence in the literature. A prescribing information section has been added to the topic, to include antibiotic treatment options for suspected acute epididymo-orchitis if not managed by a specialist sexual health clinic.

July 2021 — minor update. Change of wording to apply gender neutral descriptions.

June 2021 — minor update. Additional information on managing possible adverse effects of fluoroquinolones have been added to this topic in line with the Medicines and Healthcare products Regulatory Agency (MHRA) drug safety update Fluoroquinolone antibiotics: new restrictions and precautions for use due to very rare reports of disabling and potentially long-lasting or irreversible side effects (MHRA, 2019).

March 2021 — minor update. A typographical error has been corrected.

September 2020 — minor update. Treatment recommendations for epididymo-orchitis have been updated in line with the British Association for Sexual Health and HIV (BASHH) publication United Kingdom BASHH national guideline for the management of epididymo-orchitis (BASHH, 2020).

August 2019 — minor update. The topic has been updated in line with the East Midlands Clinical Networks guideline Management of Paediatric Torsion (East Midlands Clinical Networks, 2019) and BMJ Best Practice publication Testicular torsion (BMJ, 2019). The advice that examination of the testes should be performed in all male patients presenting with abdominal pain has been added. 

September 2017 — minor update. The manufacturers' Summary of Product Characteristics (SPC) update on quinolones has been included to align all CKS topics prescribing advice. Prostatitis – chronic, Gonorrhoea, Pyelonephritis, Diarrhoea – prevention and advice for travellers, Dyspepsia – unidentified cause, Dyspepsia – proven functional, Dyspepsia – proven peptic ulcer, Diverticular disease, Gastroenteritis and Scrotal swellings. 

March to April 2017 — reviewed. A literature search was conducted in March 2017 to identify evidence-based guidelines, UK policy, systematic reviews, and key randomized controlled trials published since the last revision of the topic. Some minor structural changes have been made to this topic. There have been no major changes to recommendations. 

February 2013 — minor update. The National Institute for Health and Care Excellence (NICE) 2013 QIPP options for local implementation have been added to this topic.

October 2011 — minor update. The dose of intramuscular ceftriaxone has been increased from 250 mg to 500 mg to reflect the reduced sensitivity of Neisseria gonorrhoeae to cephalosporins and the current British Association for Sexual Health and HIV (BASHH) treatment guidelines for uncomplicated gonorrhoea. Issued in November 2011.

July 2010 — minor update. Minor text changes to include recommendations from the BASHH UK national guideline for the management of epidiymo-orchitis. Issued in September 2010.

October 2009 to February 2010 — this is a new CKS topic. The evidence base has been reviewed in detail, and recommendations are clearly justified and transparently linked to the supporting evidence.

New evidence

Evidence-based guidelines

No new evidence-based guidelines since 1 April 2026.

HTAs (Health Technology Assessments)

No new HTAs since 1 April 2026.

Economic appraisals

No new economic appraisals relevant to England since 1 April 2026.

Systematic reviews and meta-analyses

No new systematic reviews or meta-analysis which reach the CKS threshold for inclusion since 1 April 2026.

Primary evidence

No new primary evidence which reaches the CKS threshold for inclusion published since 1 April 2026.

New policies

No new national policies or guidelines since 1 April 2026.

New safety alerts

No new safety alerts since 1 April 2026.

Changes in product availability

No changes in product availability since 1 April 2026.

Testicular torsion

Testicular torsion:

• This is a surgical emergency that describes twisting of the spermatic cord and subsequent loss of blood supply to the testicle .
  • Testicular torsion is most common in males aged 12–18, accounting for around two‑thirds of cases.
  • It also has a neonatal peak, though this is far less common.
  • Torsion affects approximately 1 in 800 males over their lifetime.
  • Annual incidence in males in the UK under 25 is around 1 in 4000.
  • It may also occur prenatally.
    • Extravaginal torsion predominates in utero and in neonates, where there is twisting of the entire cord, including the processus vaginalis. This occurs before the testis is fixed in the scrotum by the gubernaculum. The exact cause is unknown, and an anatomical defect is not usually identified. The prognosis for testicular viability in neonates is poor.
    • In older children and adults, testicular torsion is usually intravaginal, where there is twisting of the cord within the tunica vaginalis. This is commonly due to a 'bell clapper deformity', where there is abnormal fixation of the posterior lateral aspect of the testes to the tunica vaginalis, allowing the testicle to swing and rotate within the tunica vaginalis. Presence of a testicular tumour increases the risk of testicular torsion.
• Complications depend on the time between symptom onset and detorsion, and the degree of cord twisting, and include:
  • Testicular atrophy, ischaemia, and necrosis.
  • Segmental ischaemia of the testicle (if there is chronic intermittent torsion).
  • Subfertility or infertility. See the CKS topic on Infertility for more information.
  • Torsion of the contralateral testis (40% risk of torsion if fixation of the contralateral side is not performed).

Torsion of the testicular or epididymal appendage (also known as torsion of the appendix testis, appendix epididymis, or testicular hydatids):

• The appendix testis and appendix epididymis are embryological remnants at the upper pole of the testis. Torsion of testicular or epididymal appendages can occur spontaneously at any age, but is more common in pre-pubertal children.
  • It is usually self-limiting and can be managed conservatively.

[RCS, 2016a; Francavilla, 2023; Hosokawa, 2024; NCEPOD, 2024; Radmayr, 2026]

Testicular cancer

• Testicular tumours account for 1–2% of all paediatric solid tumours, the majority of which are benign.
• Testicular cancer accounts for 1% of adult cancers and 5% of adult urological tumours.
  • It is the most common solid tumour detected in males aged 15–34 years.
  • The majority of pre-pubertal testicular tumours are yolk sac tumours (malignant germ cell tumours) and teratomas (usually benign in pre-pubertal children).
  • Around 90–95% of post-pubertal tumours are germ cell tumours, mainly teratomas and seminomas.
  • Predisposing or associated factors include:
    • White ethnicity.
    • Family history of testicular cancer in a first-degree relative.
    • Undescended testis (cryptorchidism), even after orchidopexy surgery. See the CKS topic on Undescended testes for more information.
    • Hypospadias.
    • Sub- or infertility. See the CKS topic on Infertility for more information.
    • Klinefelter's syndrome.
    • History of a contralateral tumour.
    • Testicular intraepithelial neoplasia.

[Baird, 2018; Laguna, 2021; Radmayr, 2026]

Squamous cell carcinoma of the scrotum

• Squamous cell carcinoma of the scrotum is extremely rare.
  • It may be associated with occupational exposure to carcinogenic polycyclic aromatic hydrocarbons, for example, in car mechanics, car and aeroplane manufacture, gas workers, engineers, steel manufacture, and aluminium workers [Vyas, 2014].
  • It can also occur as a complication of human papillomavirus (HPV) infection or PUVA (psoralen plus ultraviolet A) phototherapy for psoriasis. See the CKS topic on Psoriasis for more information [Vyas, 2014].
  • The median age at diagnosis is 52–57 years [Vyas, 2014].

Inguinal hernia

• An inguinal hernia is a protrusion of the abdominal or pelvic contents through a dilated internal inguinal ring alongside the spermatic cord, which also extends down the inguinal canal into the scrotum [Simons, 2018].
  • Inguinal hernias are categorized as either direct or indirect, based on the relationship of the hernia sac to the inferior epigastric artery.
  • Indirect inguinal hernias usually occur because of a persistent processus vaginalis. If an inguinal hernia extends into the scrotum, it is almost always indirect.
  • A lifetime risk of inguinal hernia repair of 27% in men is cited in the literature. Up to 50% of people who develop an inguinal hernia will present with clinically evident bilateral involvement, or will develop a contralateral inguinal hernia in their lifetime.
• Possible risk factors for inguinal hernia include [Simons, 2018]: 
  • Positive family history.
  • Previous contralateral hernia.
  • Increased age.
  • Connective tissues disorders (such as Marfan's syndrome or Ehlers-Danlos syndrome with abnormal collagen metabolism).
• Complications are rare, but include [Bowling, 2017; Simons, 2018]:
  • Incarceration — this describes an inability to reduce the hernia mass into the abdomen, and typically presents with severe pain over a swelling in the groin or scrotum.
  • Strangulation — this describes when the blood supply to the herniated tissues is compromised, causing ischaemia. Clinical features include an acutely painful, firm, tender, irreducible mass.
  • Intestinal obstruction — if a hernia contains small bowel that becomes obstructed, clinical features include vomiting, abdominal pain, and swelling.
  • Recurrence after surgical repair — recurrence rates of up to 15% have been reported in the literature.
  • Chronic pain — pain lasting more than 3 months may occur in 10–12% of cases in the literature.

Epididymo-orchitis

• Epididymo-orchitis is a clinical syndrome of pain, swelling, and inflammation of the epididymis and/or testis.
  • Epididymitis and orchitis may each occur alone or in combination.
  • Underlying causes can be infectious or non-infectious:
• In pre-pubertal children, epididymo-orchitis is usually idiopathic and self-limiting.
  • It may be secondary to recent adenovirus, enterovirus, or other viral infection.
  • It may be due to reflux of urine into the ejaculatory ducts, with associated structural urogenital abnormalities.
  • Rarely, it is caused by enteric organisms that cause urinary tract infections (UTIs), which may be associated with structural or functional abnormalities of the urinary tract in children.
  • See the CKS topic on Urinary tract infection - children for more information.
• In sexually active people aged up to 35 years, it is usually caused by local spread of sexually transmitted infections (STIs) such as Chlamydia trachomatis or Neisseria gonorrhoeae from the urethra.
  • See the CKS topics on Chlamydia - uncomplicated genital and Gonorrhoea for more information.
• In people aged 35 years or older with a low-risk sexual history, it is usually caused by enteric organisms such as Escherichia coli that cause UTIs, which spread from the bladder.
  • People at increased risk include those with structural abnormalities of the urinary tract, recent urological surgery or instrumentation including urinary catheterization, positive urine dipstick test, and men who have insertive anal sex.
• Rare causes of epididymo-orchitis include mumps infection (causes unilateral or bilateral parotid swelling which precedes usually unilateral orchitis, often in young adults), Behçet's disease, vasculitis (such as Henoch-Schonlein purpura in children), brucellosis, candida infection, tuberculosis infection, or an adverse effect of amiodarone drug treatment. See the CKS topics on Mumps, Candida - oral, and Tuberculosis for more information.
• Complications are usually associated with enteric causative organisms, and include:
  • Sepsis.
    • See the CKS topic on Sepsis for more information.
  • Abscess formation and ischaemia/infarction of the testicle.
  • Reactive hydrocele.
  • Testicular atrophy and subfertility, for example due to mumps orchitis. See the CKS topic on Infertility for more information.
  • Chronic scrotal pain.

[Ziegelmann, 2019; Chirwa, 2021; Bonkat, 2026; Justice, 2026; Radmayr, 2026]

Haematocele

• A haematocele typically results from direct trauma to the scrotum (including iatrogenic trauma from aspiration of a hydrocele), although idiopathic cases can occur [Waterloos, 2026].

Epididymal cyst or spermatocele

• Epididymal cysts and spermatoceles are benign, usually small, non-painful cystic swellings of the epididymis, which may be multiple and are frequently bilateral. The cause is unknown [RCS, 2016a; Sigalos, 2017].
  • If the cyst contains spermatozoa (usually seen on histology only), it may be referred to as a spermatocele.

Hydrocele

• A simple hydrocele is an abnormal collection of serous fluid between the parietal and visceral layers of the tunica vaginalis membrane that surrounds the testis, or along the spermatic cord.
  • A communicating hydrocele results from patency of the processus vaginalis which allows peritoneal fluid to freely communicate with the scrotal portion of the processus [Radmayr, 2026].
    
    • The processus vaginalis persists in 80–94% of newborns and 20% of adults.
    • An abdomino-scrotal hydrocele is rare, when a simple hydrocele enlarges through the inguinal canal resulting in an abdominal component.
    • A hydrocele of the spermatic cord occurs when the processus vaginalis closes segmentally, trapping fluid anywhere along the spermatic cord.
    • Most congenital simple hydroceles spontaneously resolve by 12 months of age [Radmayr, 2026].
  • Possible causes of a late-onset, non-communicating hydrocele in adolescents and adults include [Chirwa, 2021; Radmayr, 2026]:
    • Minor trauma.
    • Infection and epididymitis.
    • Testicular torsion.
    • Varicocele surgery (due to ligation of the lymphatics).
    • Testicular cancer.

Varicocele

• A varicocele is an abnormal dilatation of the testicular veins in the pampiniform plexus of the spermatic cord, caused by venous reflux [Sigalos, 2017; Radmayr, 2026].
  • It is often asymptomatic and is unusual in children under 10 years of age. It is present in about 15% of adolescent and adult males.
  • About 90% occur on the left side, and about 10% of cases are bilateral.
  • There may be associated fertility problems in 20% of affected adolescents.
• See the CKS topic on Varicocele for more information on causes, assessment, and management.

Differentiating clinical features

Table 1. The main clinical features of possible testicular causes of scrotal pain and swelling.

Table 2. The main clinical features of possible extra-testicular causes of scrotal pain and swelling.

Basis for recommendation

The recommendations on assessment are largely based on the European Association of Urology (EAU) guidelines Testicular cancer [Heidenreich, 2026], Paediatric urology [Radmayr, 2026] and Urological trauma [Waterloos, 2026], the National Institute for Health and Care Excellence (NICE) guideline Suspected cancer: recognition and referral [NICE, 2026]; the British Association for Sexual Health and HIV (BASHH) National guideline for the management of epididymo-orchitis, 2021 [Chirwa, 2021]; commissioning guides from the Royal College of Surgeons (RCS) on Asymptomatic scrotal swelling [RCS, 2016b], Groin hernia [RCS, 2016c], and Management of paediatric torsion [RCS, 2016a]; and expert opinion in review articles on squamous cell carcinoma of the scrotum [Vyas, 2014], and on chronic scrotal pain [Sigalos, 2017; Tan, 2017; Ziegelmann, 2019].

Having a low threshold for suspecting testicular torsion

• The recommendation to exclude testicular torsion first in any person presenting with acute unilateral scrotal pain and/or swelling is based on the fact that history and physical examination are unreliable in confirming or excluding this diagnosis, and if suspected, emergency surgical admission is needed. Delayed diagnosis and management of testicular torsion can result in loss of testicular function and viability [RCS, 2016a; Francavilla, 2023; Hosokawa, 2024; NCEPOD, 2024; Radmayr, 2026].

Clinical features on history taking

• These recommendations are based on the EAU guideline on testicular cancer [Heidenreich, 2026], the BASHH guideline on epididymo-orchitis [Chirwa, 2021], and expert opinion in review articles [Sigalos, 2017; Tan, 2017; Baird, 2018; Ziegelmann, 2019].
  • The clinical features of intermittent torsion are based on the BASHH guideline. There is a risk of segmental ischaemia of the testicle if there is chronic intermittent torsion.
  • In mumps orchitis, unilateral testicular swelling may occur 7–10 days after unilateral or bilateral parotid swelling [Chirwa, 2021].
  • Testicular cancer may present with gynaecomastia or back or flank pain, supraclavicular or retroperitoneal lymphadenopathy [Baird, 2018; Heidenreich, 2026].
  • An accurate sexual history is important to help identify potential causative organisms of epididymo-orchitis [Chirwa, 2021].
  • A history of recent urological surgery or instrumentation, or urinary tract infection (UTI) may increase the risk of epididymo-orchitis [Chirwa, 2021].

Clinical features on examination

• These recommendations are based on the EAU guideline on testicular cancer [Heidenreich, 2026], the European and BASHH guidelines on epididymo-orchitis [Justice, 2026; Chirwa, 2021], and expert opinion in review articles [Sigalos, 2017; Tan, 2017; Baird, 2018; Ziegelmann, 2019].

Arranging an urgent ultrasound scan of the scrotum

• The recommendation to arrange a scan if there is diagnostic uncertainty is based on the BASHH guideline on epididymo-orchitis [Chirwa, 2021], the EAU guideline on paediatric urology [Radmayr, 2026], and the RCS commissioning guide on asymptomatic scrotal swelling [RCS, 2016b].
• The recommendation on persistent, unexplained testicular symptoms is based on the NICE guideline on suspected cancer [NICE, 2026].
• The recommendation on if it is not possible to determine if a mass is intra- or extra-testicular is based on the EAU guidelines on testicular cancer [Heidenreich, 2026] and paediatric urology [Radmayr, 2026].
  • Ultrasound scan can confirm the presence of a testicular mass; determine if a mass is intra- or extra-testicular; determine the volume and anatomical location of a testicular lesion; and characterize the contralateral testicle to identify any other lesions or risk factors for testicular cancer [Heidenreich, 2026].
  • If there is any uncertainty about the nature of an intrascrotal mass, ultrasound of the scrotum has a nearly 100% sensitivity in detecting intrascrotal lesions. Doppler ultrasound can help distinguish a hydrocele from varicocele and testicular torsion [Radmayr, 2026].
• The recommendation on a hydrocele in a person aged 18–40 years is extrapolated from the EAU guideline on testicular cancer, which notes that this cancer usually presents in adolescents and adults [Heidenreich, 2026].
• The recommendation on men with a history of urological trauma and scrotal pain is based on the EAU guideline on urological trauma, which notes that ultrasound can help determine if there is intra- or extra-testicular haematoma, testicular contusion, or rupture [Waterloos, 2026]. CKS notes that these conditions would usually present with acute-onset symptoms.
• The recommendation on men with a haematocele that is atraumatic or chronic is based on the EAU guideline on urological trauma, which notes that surgery may be needed, depending on the relative size of the haematocele [Waterloos, 2026].

When not to arrange an ultrasound of the scrotum

• The recommendation to arrange urgent or emergency specialist assessment if there is an acute-onset suspected serious diagnosis such as testicular torsion, acute epididymitis, or strangulated inguinal hernia is based on the EAU guideline on paediatric urology [Radmayr, 2026].
  • The use of doppler ultrasound can be useful for assessment of acute scrotal pain, but this should not delay intervention and emergency referral for suspected testicular torsion, for example [Radmayr, 2026].
    • Do not arrange an ultrasound in primary care if there is suspected testicular torsion, as the person needs immediate surgical exploration to reduce the likelihood of testicular ischaemia .
  • The recommendation to arrange urgent referral if there is a suspected testicular tumour is based on the NICE guideline on suspected cancer [NICE, 2026], and is supported by the RCS commissioning guide on asymptomatic scrotal swellings [RCS, 2016b].

Testing for sexually transmitted infections (STIs)

• This recommendation is based on the European and BASHH guidelines on epididymo-orchitis, which recommend STI testing if there is acute epididymo-orchitis [Chirwa, 2021; Justice, 2026] .

Testing for a urinary tract infection (UTI)

• This recommendation is based on the BASHH guideline on epididymo-orchitis [Chirwa, 2021]. It is supported by expert opinion in review articles [Sigalos, 2017; Tan, 2017; Ziegelmann, 2019]. In addition, CKS notes that a urine dipstick test result may help to rule out an alternative cause for symptoms, such as referred pain from a ureteric stone [Ziegelmann, 2019].
  • The information on a urine dipstick result indicative of an enteric causative organism is based on the BASHH guideline [Chirwa, 2021]. CKS notes that the EAU guideline on paediatric urology highlights that normal urinalysis does not exclude a diagnosis of epididymo-orchitis [Radmayr, 2026].
  • The information on a urine dipstick result indicative of an STI causative organism is based on the BASHH guideline [Chirwa, 2021].

How should I manage suspected testicular torsion?

• If a person has sudden-onset scrotal pain and testicular torsion is suspected clinically, arrange emergency hospital admission to urology or paediatric surgery, depending on clinical judgement.
• If a person has no current scrotal swelling or pain, but has a history of previous episodes of severe, self-limiting scrotal pain or swelling, arrange a urology referral, the urgency depending on the frequency and duration of episodes.
  • The British Association of Urological Surgeons (website www.baus.org.uk) information leaflet Scrotal exploration for suspected torsion of the testis may be helpful.

How should I manage suspected testicular cancer?

If a person has suspected testicular cancer on clinical examination (or incidentally following ultrasound of the scrotum):

• Arrange an urgent urology referral (using an urgent suspected cancer pathway).
  • Consider arranging blood tests for tumour markers (alpha-fetoprotein [AFP], human chorionic gonadotrophin [hCG], and lactate dehydrogenase [LDH] levels) at the time of referral, depending on local referral guidelines and availability.
  • The Macmillan Cancer Support (website www.macmillan.org.uk) patient leaflet Testicular cancer may be helpful.

How should I manage suspected squamous cell carcinoma of the scrotum?

If a person has suspected squamous cell carcinoma of the scrotum:

• Arrange an urgent suspected cancer pathway referral to a urologist or dermatologist, depending on clinical judgement.

How should I manage a suspected inguinal hernia?

If a person presents with a suspected inguinal hernia:

• If there is a suspected serious complication such as strangulation or intestinal obstruction, arrange emergency hospital admission.
• If emergency hospital admission is not needed:
  • For children and young people aged less than 18 years:
    • Arrange urgent referral to a paediatric surgeon, preferably to be seen within 2 weeks.
    • The British Association of Paediatric Surgeons (website www.baps.org.uk) patient leaflet Inguinal hernia repair (child) may be helpful.
  • For adults aged 18 years and above:
    • Arrange urgent referral to general surgery to consider surgical management if the hernia is irreducible, or only partially reducible.
    • Offer routine referral to general surgery to consider surgical management if the hernia is symptomatic but reducible, depending on clinical judgement. Note: referral may not be needed if a hernia is minimally symptomatic, and the person has significant comorbidity and declines surgery.
  • The British Hernia Society (website www.britishherniasociety.org) patient leaflet Groin hernia and you , and the NHS England Decision support tool: making a decision about inguinal hernia, may be helpful.

How should I manage an adult or adolescent with suspected epididymo-orchitis?

If an adolescent or adult has suspected epididymo-orchitis:

• If symptoms are severe, the person is systemically unwell, or there is a suspected serious complication, arrange emergency hospital admission.
• If hospital admission is not needed, identify the most likely causative organism based on the person's age, urine dipstick test results, and risk factors to guide management.
  • Assess the risk of a sexually transmitted infection (STI), such as chlamydia or gonorrhoea. See the CKS topics on Chlamydia and Gonorrhoea for more information on risk factors and diagnosis.
  • Assess the risk of an enteric organism associated with lower urinary tract infection (UTI). See the CKS topic on Urinary tract infection (lower) - men for more information.
  • Consider the possibility of other rare causes such as mumps orchitis, and manage appropriately.
• If an STI is the most likely cause, advise urgent referral to a local specialist sexual health clinic for STI testing, treatment, and possible contact tracing.
  • If urgent referral to a sexual health specialist is not possible, see the section on Antibiotic treatment regimens for more information. If there is any uncertainty about management in primary care, seek urgent specialist advice.
• If an enteric organism is the most likely cause:
  • Ensure a urine dipstick test and mid-stream urine (MSU) sample for microscopy and culture have been arranged. See the section on Assessment for more information.
  • Consider treating empirically with oral ofloxacin 200 mg twice daily for 14 days, or oral levofloxacin 500 mg once daily for 10 days. If there is any uncertainty about management in primary care, seek urgent specialist advice.
    • If a quinolone antibiotic is contraindicated, treat with oral co-amoxiclav 500/125 mg three times a day for 10 days.
    • See the sections on Ofloxacin, Levofloxacin, and Co-amoxiclav in Prescribing information for more information on contraindications, cautions, adverse effects, and drug interactions.
• If treating with fluoroquinolone antibiotics in primary care, advise about potential adverse effects:
  • Advise the person that this class of antibiotic can very rarely cause long-lasting, potentially irreversible adverse effects affecting the tendons, muscles, joints, and/or central nervous system. See the sections on Ofloxacin and Levofloxacin in Prescribing information for more detailed information on contraindications, cautions, adverse effects, and drug interactions.
  • Advise the person to stop fluoroquinolone antibiotic treatment immediately and seek immediate medical advice if they develop serious tendon, muscle, or joint pain or inflammation.
  • Provide the person with the patient information found in the MHRA Drug Safety Update on fluoroquinolone antibiotics.
• Give advice on self-management measures and when to arrange follow up.
  • Advise on rest, scrotal support (such as with supportive underwear), and the use of analgesia such as paracetamol and/or nonsteroidal anti-inflammatory drugs (NSAIDs) until symptoms improve.
    • See the CKS topics on Analgesia - mild-to-moderate pain and NSAIDs - prescribing issues for more information on contraindications, cautions, adverse effects, and possible drug interactions.
    • The British Association for Sexual Health and HIV (BASHH) patient leaflet Epididymo-orchitis may be helpful.
  • If symptoms worsen, or are not improving after 3 days of antibiotic treatment, advise the person to seek urgent medical review. See the section on Follow up of adults and adolescents for more information.

How should I follow up a person with epididymo-orchitis?

If a person has a diagnosis of epididymo-orchitis and has started first-line management:

• If symptoms have worsened or are not improving after 3 days of antibiotic treatment:
  • Check compliance with treatment.
  • Check results of any initial investigations, and amend treatment as necessary when results are available.
    • If an enteric organism is confirmed, arrange a urology referral to investigate for an underlying structural or functional abnormality or urinary tract obstruction. See the CKS topic on Urinary tract infection (lower) - men for more information.
    • If a sexually transmitted infection (STI) is suspected or confirmed, check sexual abstinence and ensure that partner notification is complete if not already undertaken. See the CKS topics on Chlamydia - uncomplicated genital, Gonorrhoea, HIV infection and AIDS, Syphilis, and Trichomoniasis for more information on management and follow up.
  • Consider an alternative diagnosis, including an infective or non-infective cause, and manage appropriately.
• Ensure the person is reviewed after 2 weeks.
  • Check compliance with treatment.
  • Check symptoms have improved or resolved.
    • Reassure that scrotal swelling completely resolves in more than 80% of people by 3 months after antibiotic treatment.
    • If symptoms are persisting, consider arranging an ultrasound scan of the scrotum and/or urology referral, the urgency depending on clinical judgement. The British Association of Urological Surgeons (website www.baus.org.uk) patient leaflet Chronic epididymitis may be helpful.
  • If an STI cause is suspected or confirmed, check sexual abstinence and ensure partner notification is complete.

How should I manage a pre-pubertal child with suspected epididymo-orchitis?

If a pre-pubertal child has suspected epididymo-orchitis:

• If symptoms are severe, the child is systemically unwell, or there is a suspected serious complication, arrange emergency hospital admission.
• If a diagnosis of mumps orchitis is suspected, see the CKS topic on Mumps for more information on management.
• Arrange a urine dipstick test and mid-stream urine (MSU) sample for microscopy and culture, and manage depending on the result.
  • If a urinary tract infection (UTI) is confirmed, seek specialist advice on the choice of antibiotic, dose, and duration of treatment, and arrange onward referral to a paediatrician as appropriate. 
    • See the CKS topic on Urinary tract infection - children for more information on diagnosis and management.
  • If a UTI is not confirmed, do not start antibiotic treatment routinely in primary care.
    • Reassure parents/carers that epididymitis is usually a self-limiting condition which resolves with rest and analgesia such as paracetamol and/or nonsteroidal anti-inflammatory drugs (NSAIDs) as needed. See the CKS topics on Analgesia - mild-to-moderate pain and NSAIDs - prescribing issues for more information on contraindications, cautions, adverse effects, and possible drug interactions.
    • If there is any uncertainty about management in primary care, seek specialist advice or consider arranging referral to paediatric urology, the urgency depending on clinical judgement. 

How should I manage a haematocele?

If the person has a suspected haematocele:

• If it follows acute trauma, arrange emergency hospital admission.
• If it is atraumatic or chronic, arrange referral for an urgent ultrasound of the scrotum and onward urology referral as appropriate.
  • Small haematoceles (smaller than three times the size of the contralateral testis) can be managed conservatively.
  • Large haematoceles may need surgical management.
  • If there is any uncertainty regarding management, seek specialist advice.

How should I manage an epididymal cyst or spermatocele?

• If there is a confirmed diagnosis of epididymal cyst (for example clinically or following ultrasound of the scrotum):
  • Reassure the person it is a common harmless finding, is usually asymptomatic, and rarely needs treatment.
  • If the person has bothersome symptoms, offer a routine referral to urology. The British Association of Urological Surgeons (website www.baus.org.uk) patient leaflet Removal of epididymal cyst may be helpful.

How should I manage a congenital hydrocele?

• If an infant has a suspected congenital hydrocele since birth:
  • Reassure the parents/carers that the hydrocele is likely to resolve without treatment by 12 months of age.
    • The British Association of Paediatric Surgeons (website www.baps.org.uk) patient leaflet Hydrocele repair (child) may be helpful.
  • Arrange referral to a paediatric surgeon, the urgency depending on clinical judgement, if:
    • A simple, non-communicating hydrocele either is not decreasing in size, or is still present after 12 months of age.
    • A concomitant inguinal hernia or underlying testicular pathology is suspected.
    • The hydrocele is localized to the spermatic cord.
    • There is also a palpable abdominal mass (suggesting an abdomino-scrotal hydrocele).

How should I manage a non-congenital hydrocele?

If there is a suspected non-congenital hydrocele in an adolescent or adult:

• Assess whether the hydrocele may be due to an underlying cause, such as testicular torsion, testicular cancer, epididymo-orchitis, trauma, or varicocele surgery.  
  • Arrange emergency hospital admission or specialist referral, depending on the possible underlying cause. 
  • If the person is 18–40 years of age, or the testis cannot be palpated, arrange an urgent ultrasound scan of the scrotum. See the section on Assessment for more information.
• If there is no underlying cause and an idiopathic hydrocele is suspected, reassure the person and advise on scrotal support (such as use of supportive underwear).
• If the person has a large, symptomatic hydrocele, arrange referral to a urologist or paediatric surgeon, depending on clinical judgement. The British Association of Urological Surgeons (website www.baus.org.uk) patient leaflet Repair of a scrotal hydrocele may be helpful.

Contraindications and cautions

• Do not prescribe doxycyline to people with:
  • Known hypersensitivity to any of the tetracyclines.
  • Acute porphyria.
• Prescribe doxycyline with caution in people with:
  • Myasthenia gravis — tetracyclines may increase muscle weakness symptoms.
  • Systemic lupus erythematous — tetracyclines may exacerbate symptoms.
  • Hepatic impairment — manufacturer advises avoid if possible.
  • Renal impairment — manufacturer advises avoid excessive doses.
  • Alcohol dependency.

 [BNF, 2026]

Adverse effects

• Blood disorders — haemolytic anaemia, thrombocytopenia, neutropenia, eosinophilia (rare).
• Gastrointestinal — nausea, vomiting, diarrhoea (common), dyspepsia (uncommon). Abdominal discomfort, tooth discolouration, and enamel hypoplasia in children (frequency unknown).
  • Rarely: dysphagia, oesophagitis, oesophageal irritation, pseudomembranous colitis. For more information, see the CKS topic on Diarrhoea - antibiotic associated. (Advice to swallow the capsules with plenty of water, in an upright position, and well before going to bed helps to reduce the frequency of oesophagitis and oesophageal ulceration.)
• Immune system disorders – hypersensitivity common (including anaphylaxis, angioedema, exacerbation of systemic lupus erythematosus, Henoch-Schonlein purpura). Rarely drug reaction with eosinophilia and systemic symptoms (DRESS).
• Hepatic disorders – hepatotoxicity, hepatitis, jaundice, hepatic failure (frequency unknown).
• Renal disorders — blood urea increased.
• Skin — photosensitivity, rash (common).
  • Rarely: toxic epidermal necrolysis, Stevens–Johnson syndrome, erythema multiforme, exfoliative dermatitis, and fixed eruption.
• Other rare adverse effects include:
  
  • Arthralgia, myalgia.
  • Flushing.
  • Severe headache and/or visual disturbances — may be an early symptom of benign intracranial hypertension, a rare but serious adverse effect. Headache is a relatively common side effect.
  • Tinnitus.

[BNF, 2026; EMC, 2026]

Drug interactions

Possible drug interactions associated with doxycycline include:

• Antacids (containing aluminium, bismuth, calcium, or magnesium) and other medications containing iron or zinc — these reduce the absorption of tetracyclines if taken concurrently.
  • Avoid taking antacids and other medications containing iron or zinc 2 hours before or after taking tetracyclines.
• CYP3A enzyme inducers (phenobarbital, carbamazepine, or phenytoin) — these may reduce the serum half-life of doxycycline. Monitor and adjust the dose if necessary.
• Flucloxacillin — concurrent use increases risk of hepatotoxicity.
• Fluconazole — concurrent use increases risk of hepatotoxicity.
• Insulin — the blood-glucose lowering effect may be increased if taken with doxycycline. Monitor blood-glucose levels.
• Lithium — lithium levels may be increased by doxycycline. Manufacturer advises avoid or adjust dose.
• Methotrexate — concurrent use increases risk of hepatotoxicity.
• Paracetamol — concurrent use increases risk of hepatotoxicity.
• Retinoids — there is a possible increased risk of benign intracranial pressure if tetracyclines are used concurrently with retinoids (such as isotretinoin). Avoid the concurrent use of tetracyclines and retinoids.
• Rifampicin — doxycycline levels are markedly reduced, which may lead to treatment failure. Monitor the effects and increase doxycycline dose if necessary.
• Statins — concurrent use increases risk of hepatotoxicity.
• Sulfasalazine — concurrent use increases risk of hepatotoxicity.
• Valproate — concurrent use increases risk of hepatotoxicity. 
• Warfarin — the concurrent use of warfarin with tetracyclines may increase the anticoagulant effect. Consider monitoring the person's international normalized ratio (INR) regularly and within 3 days of starting the tetracycline. Adjust the warfarin dose accordingly.

[BNF, 2026]

Contraindications and cautions

• Note that systemic fluoroquinolones must only be prescribed when other commonly recommended antibiotics are inappropriate. This follows a review by the MHRA which looked at the effectiveness of current measures to reduce the identified risk of disabling and potentially long-lasting or irreversible side effects.
• Do not prescribe ofloxacin to people with:
  • A history of tendon disorders related to quinolone use, or previous serious adverse reactions to a quinolone or fluoroquinolone antibiotic.
• Prescribe ofloxacin with caution to people with:
  • Age over 60 years — increased risk of tendon damage and aortic aneurysm and dissection in older people.
  • Aortic aneurysm and/or aortic dissection, a family history of aneurysm, or other risk factors or conditions predisposing to aortic aneurysm and dissection (such as Marfan syndrome, Ehlers-Danlos syndrome, Takayasu arteritis, giant cell arteritis, Behcet's disease, hypertension, atherosclerosis) — small increased risk of aortic aneurysm and dissection.
  • Congenital or pre-existing heart valve disease, or with risk factors or conditions predisposing to heart valve regurgitation (such as Turner's syndrome, Behcet's disease, rheumatoid arthritis, and infective endocarditis) — small increased risk of heart valve regurgitation.
  • Conditions which predispose to QT interval prolongation:
    • Concurrent use of drugs that are known to prolong the QT interval (for example Class IA and III anti-arrhythmics, tricyclic antidepressants, macrolides, antipsychotics).
    • Electrolyte imbalance (for example hypokalaemia or hypomagnesaemia).
    • Cardiac disease (for example heart failure, myocardial infarction, bradycardia, congenital long QT syndrome, history of arrhythmias).
  • Solid-organ transplant — increased risk of tendon damage.
  • Diabetes mellitus — may affect blood glucose.
  • A history of tendonitis — quinolones can very rarely cause tendon damage.
  • Conditions which predispose to seizures; history of epilepsy — quinolones may induce convulsions in people with a history of convulsions, and the risk is increased in people taking a nonsteroidal anti-inflammatory drug (NSAID). Concurrent NSAID use should be avoided in people with epilepsy or with conditions that predispose to seizures.
  • Hepatic impairment — liver damage can occur (risk of decreased elimination).
  • Renal impairment — increased risk of tendon damage; reduce the dose if creatinine clearance is less than 50 mL/minute.
  • Glucose-6-phosphate dehydrogenase (G6PD) deficiency.
  • Psychiatric disorders — reports of suicidal thoughts or self-endangering behaviour after quinolone use.
  • Myasthenia gravis — may exacerbate symptoms.

 [MHRA, 2018; MHRA, 2019; MHRA, 2020; MHRA, 2023; EMC, 2025a; BNF, 2026]

Adverse effects

Possible adverse effects of ofloxacin include:

• Cardiovascular
  • Tachycardia, ventricular arrhythmias, torsades de pointes, QT interval prolongation.
  • There is an increased risk of aortic aneurysm and dissection with fluoroquinolones (rare). Advise to seek immediate medical attention if sudden-onset severe abdominal, chest, or back pain develops [MHRA, 2018].
  • Heart valve regurgitation — advise to seek immediate medical attention if there is rapid-onset breathlessness (especially if lying flat); ankle, foot, or abdominal swelling; or new-onset heart palpitations [MHRA, 2020].
• Gastrointestinal
  • Diarrhoea, constipation, nausea, vomiting, reduced appetite, abdominal pain.
• Musculoskeletal
  • Arthralgia, myalgia, tendon damage including tendonitis and tendon rupture (rare) [MHRA, 2019].
    • Tendon rupture may occur within 48 hours of starting treatment, or months after stopping a quinolone. Risk of tendon rupture is increased by concomitant corticosteroids and in people aged over 60 years. If tendonitis or tendon rupture is suspected, advise to stop ofloxacin immediately and seek medical advice [MHRA, 2019].
• Central nervous system (CNS)
  • Headache, dizziness, sleep disorders, taste disorders, tinnitus, tremor, vertigo, visual disturbances.
    • If peripheral neuropathy, muscle weakness, or serious CNS adverse effects are suspected, advise to stop ofloxacin immediately and seek medical advice [MHRA, 2019].
• Psychiatric
  • Agitation, sleep disorder, confusion, anxiety, depression, nightmares.
• Skin
  • Rash, pruritus (uncommon).
• Other
  • Anaphylaxis, fever, increased risk of infection, dyspnoea.
• People should be advised to stop fluoroquinolone treatment at the first signs of a serious adverse reaction, such as tendinitis or tendon rupture, muscle pain, muscle weakness, joint pain, joint swelling, peripheral neuropathy or central nervous system effects. Remain alert to the risk of suicidal thoughts and behaviours with use of fluoroquinolone antibiotics. 

Report suspected adverse drug reactions to fluoroquinolone antibiotics on the Yellow Card website: https://yellowcard.mhra.gov.uk/.

 [MHRA, 2018; MHRA, 2019; MHRA, 2020; MHRA, 2023; EMC, 2025a; BNF, 2026]

Drug interactions

Possible drug interactions associated with ofloxacin include:

• Antacids (containing aluminium, calcium, or magnesium) and other medications containing iron or zinc — these may reduce the absorption of ofloxacin if taken concurrently.
  • Ofloxacin should be taken at least 2 hours before these preparations, and not less than 4–6 hours after them.
• Celecoxib and other COX-2 inhibitors — celecoxib potentially increases the risk of seizures when given with ofloxacin. Manufacturer advises caution.
• Corticosteroids — the risk of tendonitis and tendon rupture is increased in people taking a fluoroquinolone and a corticosteroid. Concurrent use should be avoided. 
• Nonsteroidal anti-inflammatory drugs (NSAIDs) — potentially increased risk of seizures when quinolones are given with NSAIDs. Manufacturer advises caution.
• Strontium ranelate — the absorption of quinolones is reduced by strontium ranelate. Manufacturer advises avoid.
• Warfarin — ofloxacin increases the anticoagulant effect of warfarin. The manufacturer advises to monitor the international normalized ratio (INR).
• Drugs that prolong the QT interval (such as Class IA and III anti-arrhythmics, tricyclic antidepressants, macrolides, and antipsychotics) — very rare cases of QT interval prolongation have been reported in people taking quinolones and they should therefore be prescribed with caution alongside drugs known to prolong the QT interval.

 [MHRA, 2019; BNF, 2026]

Contraindications and cautions

• Note that systemic fluoroquinolones must now only be prescribed when other commonly recommended antibiotics are inappropriate. This follows a review by the MHRA which looked at the effectiveness of current measures to reduce the identified risk of disabling and potentially long-lasting or irreversible side effects.
• Do not prescribe levofloxacin to people with:
  • A history of tendon disorders related to quinolone use, or previous serious adverse reactions to a quinolone or fluoroquinolone antibiotic.
• Prescribe levofloxacin with caution to people with:
  • Age over 60 years — increased risk of tendon damage and aortic aneurysm and dissection.
  • Aortic aneurysm and/or aortic dissection, a family history of aneurysm, or other risk factors or conditions predisposing to aortic aneurysm and dissection (such as Marfan syndrome, Ehlers-Danlos syndrome, Takayasu arteritis, giant cell arteritis, Behcet's disease, hypertension, atherosclerosis) — small increased risk of aortic aneurysm and dissection.
  • Congenital or pre-existing heart valve disease, or with risk factors or conditions predisposing to heart valve regurgitation (such as Turner's syndrome, Behcet's disease, rheumatoid arthritis, and infective endocarditis) — small increased risk of heart valve regurgitation.
  • Conditions which predispose to QT interval prolongation:
    • Concurrent use of drugs that are known to prolong the QT interval (for example Class IA and III anti-arrhythmics, tricyclic antidepressants, macrolides, antipsychotics).
    • Electrolyte imbalance (for example hypokalaemia or hypomagnesaemia).
    • Cardiac disease (for example heart failure, myocardial infarction, bradycardia, congenital long QT syndrome, history of arrhythmias).
  • Solid-organ transplant — increased risk of tendon damage.
  • Diabetes mellitus — may affect blood glucose.
  • A history of tendonitis — quinolones can very rarely cause tendon damage.
  • Conditions which predispose to seizures; history of epilepsy — quinolones may induce convulsions in people with a history of convulsions, and the risk is increased in people taking a nonsteroidal anti-inflammatory drug (NSAID). Concurrent NSAID use should be avoided in people with epilepsy or with conditions that predispose to seizures.
  • Renal impairment — increased risk of tendon damage; reduce the dose if creatinine clearance is less than 50 mL/minute.
  • Glucose-6-phosphate dehydrogenase (G6PD) deficiency.
  • Psychiatric disorders — reports of suicidal thoughts or self-endangering behaviour after quinolone use.
  • Myasthenia gravis — may exacerbate symptoms.

  [MHRA, 2018; MHRA, 2019; MHRA, 2020; MHRA, 2023; EMC, 2025b; BNF, 2026]

Adverse effects

Possible adverse effects of levofloxacin include:

• Cardiovascular
  • Tachycardia, ventricular arrhythmias, torsades de pointes, QT interval prolongation.
  • There is an increased risk of aortic aneurysm and dissection with fluoroquinolones (rare). Advise to seek immediate medical attention if sudden-onset severe abdominal, chest, or back pain develops [MHRA, 2018].
  • Heart valve regurgitation — advise to seek immediate medical attention if there is rapid-onset breathlessness (especially if lying flat); ankle, foot, or abdominal swelling; or new-onset heart palpitations [MHRA, 2020].
• Gastrointestinal
  • Diarrhoea, constipation, nausea, vomiting, reduced appetite, abdominal pain.
• Musculoskeletal
  • Arthralgia, myalgia, tendon damage including tendonitis and tendon rupture (rare) [MHRA, 2019].
    • Tendon rupture may occur within 48 hours of starting treatment, or months after stopping a quinolone. Risk of tendon rupture is increased by concomitant corticosteroids and in people aged over 60 years. If tendonitis or tendon rupture is suspected, advise to stop ofloxacin immediately and seek medical advice [MHRA, 2019].
• Central nervous system (CNS)
  • Headache, dizziness, sleep disorders, taste disorders, tinnitus, tremor, vertigo, visual disturbances.
    • If peripheral neuropathy, muscle weakness, or serious CNS adverse effects are suspected, advise to stop ofloxacin immediately and seek medical advice [MHRA, 2019].
• Psychiatric
  • Agitation, sleep disorder, confusion, anxiety, depression, nightmares.
• Skin
  • Rash, pruritus (uncommon).
• Other
  • Anaphylaxis, fever, increased risk of infection, dyspnoea.
  • Fluoroquinolones can very rarely cause long-lasting, disabling, and potentially irreversible adverse effects, sometimes affecting multiple organ systems [MHRA, 2019].
• People should be advised to stop fluoroquinolone treatment at the first signs of a serious adverse reaction, such as tendinitis or tendon rupture, muscle pain, muscle weakness, joint pain, joint swelling, peripheral neuropathy or central nervous system effects. Remain alert to the risk of suicidal thoughts and behaviours with use of fluoroquinolone antibiotics. 

Report suspected adverse drug reactions to fluoroquinolone antibiotics on the Yellow Card website: https://yellowcard.mhra.gov.uk/.

[MHRA, 2018; MHRA, 2019; MHRA, 2023; EMC, 2025b; BNF, 2026]

Drug interactions

Possible drug interactions associated with levofloxacin include:

• Antacids (containing aluminium, calcium, or magnesium) and other medications containing iron or zinc — these may reduce the absorption of levofloxacin if taken concurrently.
  • Levofloxacin should be taken at least 2 hours before these preparations and not less than 4–6 hours after them. 
• Celecoxib and other COX-2 inhibitors — celecoxib potentially increases the risk of seizures when given with levofloxacin. Manufacturer advises caution.
• Corticosteroids — the risk of tendonitis and tendon rupture is increased in people taking a fluoroquinolone and a corticosteroid. Concurrent use should be avoided. 
• Nonsteroidal anti-inflammatory drugs (NSAIDs) — potentially increased risk of seizures when quinolones are given with NSAIDs. Manufacturer advises caution.
• Strontium ranelate — the absorption of quinolones is reduced by strontium ranelate. Manufacturer advises avoid.
• Warfarin — levofloxacin increases the anticoagulant effect of warfarin. The manufacturer advises to monitor the international normalized ratio (INR).
• Drugs that prolong the QT interval (such as Class IA and III anti-arrhythmics, tricyclic antidepressants, macrolides, and antipsychotics) — very rare cases of QT interval prolongation have been reported in people taking quinolones and they should therefore be prescribed with caution alongside drugs known to prolong the QT interval.

[MHRA, 2019; BNF, 2026]

Contraindications and cautions

• Do not prescribe co-amoxiclav to people with:
  • A true penicillin hypersensitivity. Note: gastrointestinal adverse effects alone (such as nausea, vomiting, or diarrhoea) do not constitute an allergy to penicillin.
  • Penicillin-associated jaundice or hepatic dysfunction (risk of cholestatic jaundice).
• Prescribe co-amoxiclav with caution to people with:
  • A hypersensitivity to cephalosporins.
  • Acute or chronic lymphocytic leukaemia (increased risk of erythematous rashes).
  • Cytomegalovirus or glandular fever infection (increased risk of erythematous rashes).
  • Hepatic impairment — monitor liver function in liver disease.
  • Chronic kidney disease (CKD) — reduce the dose if the estimated glomerular filtration rate (eGFR) is 30 mL/min/1.73 m² or less.

[EMC, 2025c; BNF, 2026]

Adverse effects

Possible adverse effects of co-amoxiclav include:

• Gastrointestinal — diarrhoea (very common), nausea and vomiting (common), drug-induced enterocolitis syndrome (unknown frequency).
  • Very rarely: antibiotic-associated colitis.
• Nervous system — headache, dizziness (uncommon), aseptic meningitis (unknown frequency).
• Skin — skin rash, urticaria, pruritus (uncommon), drug reaction with eosinophilia and systemic symptoms (DRESS) (unknown frequency).
  • Very rarely: erythema multiforme, Stevens–Johnson syndrome, toxic epidermal necrolysis, bullous and exfoliative dermatitis, acute generalized exanthematous pustulosis.
• Other rare, or very rare adverse effects include:
  • Hepatitis, cholestatic jaundice.
  • Hyperactivity, convulsions.
  • Hypersensitivity reactions (serious and occasionally fatal).  
  • Interstitial nephritis.
  • Linear IgA disease (renal deposition of IgA).  
  • Leucopenia, thrombocytopenia, haemolytic anaemia.
  • Kounis syndrome (an allergic reaction which can cause myocardial infarction). 
  • Symmetrical Drug-related Intertriginous and Flexural Exanthema (SDRIFE) (unknown frequency).

[EMC, 2025c; BNF, 2026]

Drug interactions

Possible drug interactions associated with co-amoxiclav include:

• Allopurinol — concomitant use of allopurinol and amoxicillin may increase the risk of skin rash. Manufacturer advises consider alternatives.
• Anticoagulants (for example warfarin) — amoxicillin potentially changes the anticoagulant effect of warfarin. Manufacturer advises monitor the international normalized ratio (INR) and adjust the dose accordingly.
• Methotrexate — amoxicillin is predicted to increase the toxicity when given with methotrexate. Manufacturer advises monitor.

[EMC, 2025c; BNF, 2026]