We discuss the potential for abuse of pregabalin and gabapentin.

Four different analgesics are recommended by NICE for the treatment of neuropathic pain. These are the anticonvulsants, gabapentin and pregabalin, along with the tricyclic antidepressant, amitriptyline, and the serotonin-noradrenaline reuptake inhibitor, duloxetine.

It is unfortunate that NICE makes no recommendation as to which to try first (aside from some general tips around considering the benefits and adverse effects of each therapy), but this may be provided by formularies at a local level, where drug costs could be an important consideration.

Recent guidance from Public Health England (PHE) suggested prescribers should be aware that pregabalin and gabapentin can lead to dependence and may be misused or diverted. PHE warned prescribers about the dangers of prescribing in high risk patients.

A significant increase (around 50 per cent) in prescription volume is noted between 2011 and 2013. Pregabalin may be more prone to abuse than gabapentin which, anecdotally, may be reflected in a higher ‘street value’.

Like all analgesics for neuropathic pain, evidence of efficacy should be sought before the drug is prescribed on a continuing basis and individualised titration should be discussed with the patient prior to initiation. Ineffective treatments should be reduced and stopped, and an alternative agent considered where neuropathic pain continues to be problematic.

Safety tips

Tips for the safe and effective prescribing of gabapentin and pregabalin include:

• In the absence of contraindications, such as arrhythmias or recent MI, amitriptyline is a reasonable first-line alternative in most types of neuropathic pain managed outside specialist pain clinics
• Pregabalin and gabapentin should usually be avoided in patients at risk of misuse or recently discharged from secure environments (unless evidence of continued use in that environment is available)
• Counselling should also include the time to onset of action. Where effective, patients will see some improvement within three to seven days of initiation, but maximal effect may not be seen until four weeks
• Ensure the patient is aware how the drug should be titrated to minimise adverse effects. Pregabalin and gabapentin may need to be titrated slower than the BNF suggests in elderly patients.

Patient information

The British Pain Society website has a comprehensive range of patient information leaflets including ‘Understanding and managing pain‘ and ‘Pain and problem drug use’ (although this is currently being reviewed) in addition to one about each of the NICE approved analgesics.