After reading this update CPD article you should understand:
Medication overuse headache (MOH) can be debilitating. Previously known as rebound headache, drug-induced headache and medication misuse headache,1 people with MOH experience headaches:
• On 15 days or more a month
• For four or more hours a day
• For three or more months.
As many as 30-70 per cent of patients referred to specialised headache centres may have MOH.1,2 The condition can lead to absenteeism, A&E visits, hospital admissions and unnecessary diagnostic tests.1 As a result, the costs of managing MOH may be three times greater than those for migraine and more than 10 times higher than those associated with tension-type headache.
Absenteeism and reduced productivity account for about 90 per cent of the costs2 with a review concluding that “MOH is likely to be one of the most if not the most costly neurological disorder known”.1
About 1-2 per cent of the general population suffers from MOH.1 Women are about three to four times more likely than men to develop MOH – which typically emerges when patients are in their 40s – but up to 0.5 per cent of children and adolescents may have MOH.3 Most people with MOH originally suffered from migraine (65 per cent) or tension-type headache (27 per cent).1 MOH can transform episodic migraine to chronic migraine.1
Healthcare professionals should consider MOH in every patient who presents with chronic headaches. The location of pain in MOH frequently differs from the original headache disorder, which may offer a diagnostic clue. Patients with episodic migraines who develop MOH may, for instance, describe headaches in their forehead, temples or back of the head.
The headache may be unilateral, bilateral or both. Patients may believe they have more than one type of headache and expect healthcare professionals to explain the variability. Most people with MOH also experience neck pain, which can lead to misdiagnosis and ineffective treatment.1
Several groups of people seem to be at increased risk of developing MOH. For instance, those who regularly use tranquilisers (odds ratio [OR] 5.2) and people with anxiety or depression, as well as musculoskeletal and gastrointestinal complaints, are five times (OR 4.7) more likely to develop MOH. People who use analgesics for any condition (OR 3.0) and those who are inactive (OR 2.7 versus high activity) are at a three-fold increased risk of developing MOH. Pharmacists should advise smokers to quit: daily smoking increased MOH risk by 80 per cent.1
Broadly, five groups of headache medications can cause MOH: simple analgesics, non-steroidal anti-inflammatory drugs, triptans, opioids and ergotamine.4 People taking triptans seem to be particularly vulnerable to MOH. On average, people need to overuse triptans for 1.7 years before developing MOH. This compares to 2.7 years for ergotamine and 4.8 years for simple analgesics.
Similarly, the average frequency of use during a month in those who developed MOH was lowest for triptans and highest for simple analgesics.3
Often, MOH seems to arise from a combination of changes produced by the overused drug, that increase the sensitivity of pain pathways ascending from the body to the brain, and weaken the pathways descending from the brain that inhibit pain.1
Overusing triptans, for example, may induce ‘latent sensitisation’ – i.e. nerves become more likely to trigger pain, which results in increased susceptibility to migraine triggers.
Overusing paracetamol may increase the activity of some parts of the brain (cortical excitability).1
Triptans and paracetamol can alter levels of serotonin, which is important in pain processing and might contribute to the association between anxiety, depression and MOH.2
In other cases, MOH may arise because the patient is predisposed to dependency:5 up to 65 per cent of people with MOH show dependency-related behaviours, for instance.2 Many patients continue taking analgesics despite the painkillers having no significant effect on their headache.2
The pain of migraine is often described as “throbbing” and may affect one or both sides of the head, accompanied by other symptoms such as nausea, vomiting, and sensitivity to light and noise. The headache is usually made worse by physical activity. Migraines usually last from four to 72 hours and in most cases there is complete freedom from symptoms between attacks. Certain factors, such as lifestyle and hormonal changes, are involved in triggering an attack in those predisposed to migraine.
There are several types of migraine:
• Migraine with aura is when there is a warning sign, known as an aura, before the migraine begins. Warning signs may include visual problems (such as flashing lights)
and stiffness in the neck, shoulders or limbs
• Migraine without aura
• Migraine without headache, also known as silent migraine. This is when an aura or other migraine symptoms are experienced, but a headache does not develop.
Tension-type headaches are the commonest headache. The pain is often described as feeling like a tight band round the head or a weight on top of it. The neck or shoulder muscles may also hurt and the pain can last from 30 minutes to several days, or may be continuous.
Stress is one cause, but others may include drinking too much alcohol, not getting enough sleep, depression, skipping meals and becoming dehydrated.
Whereas migraine can be identified as a headache with associated features, such as nausea and sensitivity to light, people experiencing headaches without features are likely to be suffering with tension headache.
These headaches can be treated with OTC painkillers such as ibuprofen or paracetamol. Self-care advice could include learning relaxation techniques, avoiding stressful situations where possible, using hot and cold packs to relax the muscles in the head and neck, or massaging the affected areas.
Cluster headaches are even more debilitating than migraine. These excruciatingly painful headaches cause an intense pain around one eye.
A relatively rare condition, affecting one or two people in every 1,000, cluster headaches are often misdiagnosed as migraine or sinus headache and subsequently mistreated.
With cluster headaches the pain is always unilateral and, although for some people the side can vary from time to time, it is usually centred over one eye, one temple or the forehead. It can spread to a larger area making diagnosis harder. Cluster headaches occur in clusters for four to 12 weeks around the same time of year. The pain is often experienced at a similar time each day. Such patients should be referred to their GP.
Pharmacy teams are well positioned to deliver primary and secondary prevention of MOH.4 For instance, pharmacy staff can raise awareness of MOH, which seems low even among well-educated people. Researchers surveyed 485 undergraduates at Birmingham University, 197 of whom had healthcare training. Seventy-eight per cent of respondents took paracetamol. Most (85 per cent) used painkillers for headaches but only 38 per cent of the healthcare group and 14 per cent of the other respondents said they were aware of MOH as a side-effect of analgesics.6
Educating people about MOH can alter their behaviour: 80 per cent of those in the Birmingham study said that they would change their painkiller use after receiving information about MOH. Of these, 57 per cent said that they would reduce their use of painkillers, 24 per cent would consult a doctor for advice about treating headaches and 19 per cent would stop using their analgesic. Nevertheless, 27 per cent of the healthcare group and 16 per cent of the other students would not alter their behaviour.6
In another study, 76 per cent of patients no longer overused analgesics 1.5 years after receiving “simple information” and 42 per cent reverted to episodic headaches.3
Similarly, a study from Norway concluded that screening and brief intervention could help treat MOH. The authors noted that healthcare professionals may experience “challenges” persuading patients that their analgesic could cause headaches. Using MOH as a diagnosis “opened up a space for change”, the study said,
but could leave some patients feeling guilty.5
In addition, the Birmingham study suggested that pharmacists should consider using the term ‘painkiller-induced headache’ when counselling people about MOH: 43 per cent of the non-healthcare group and 37 per cent overall preferred this term. Twenty-seven per cent of the healthcare group preferred ‘painkiller-overuse headache’. Just 10 per cent preferred MOH.6
Withdrawing the overused medication usually improves MOH.3 Indeed, simple withdrawal and providing information and education can reduce MOH to episodic headaches in more than half of patients.2 Specialist services can help many other patients.
Pharmacists should warn patients that they might experience withdrawal symptoms, most commonly an initial worsening of the headache. The duration of withdrawal headaches depends on the drug: about four days for triptans, approximately seven days for ergotamine and about 10 days for simple analgesics. Some patients experience symptoms such as nausea, vomiting, sleep disturbances, anxiety, restlessness and nervousness.3
Pharmacists should be alert for relapses, which can range from a rate of 28-31 per cent within six months of withdrawal to 41 and 45 per cent at one and four years respectively. Relapse rates at four years in people with MOH from analgesics can reach 71 per cent. Several factors seem to increase the risk of relapse including:
• High initial intake of the overused analgesic
• Restarting previously overused drugs
• Failure to improve two months after stopping the drug
• Smoking and alcohol use.1
Ensuring patients are using effective pain relief is arguably the most important role of any healthcare professional. It is therefore something of a tragic irony that MOH is so common, so disabling and so costly.
Pharmacy teams have much more to offer those suffering with pain than a self-select purchase from a discounter or supermarket, says Farah Ali, general manager at Perrigo’s Warman-Freed Pharmacy. “Pharmacists and their teams have the knowledge and skills to help differentiate between the types of pain, the different pain relief products available, and their mode and speed of action.
“Branded pain relief products have a legacy that equates to trust, efficacy and belief from the shopper that they are getting the best product for the relief they require, so it is not always about a generic alternative – brand can be best.”
Dan Williams, Perrigo commercial strategy and implementation director, agrees. “In general, pain is a highly commoditised category, with nearly two-thirds of category purchases being own-brand. However, the case for pharmacy is different, as the patient is on an ‘urgent care’ mission and is looking for ways to choose a product they can trust to stop the pain. In these cases, the brand rises in importance. As a result, pharmacist and pharmacy staff recommendation is crucial to the appropriate product selection and helping the patient resolve their issue as soon as possible.”
1. Headache 2013; 54:211-217
2. Headache 2014; 54:1251-7
3. Therapeutic Advances in Drug Safety 2014; 5:87-99
4. Headache 2014; 54:1019-1025
5. British Journal of General Practice 2014; 64:e525-e531
6. The Journal of Headache and Pain 2014; 15:10-10