Useful adjuvant analgesics for neuropathic pain

Our practice is to start with amitriptyline and add an anticonvulsant if the symptoms are not relieved or to substitute an anticonvulsant if the tricyclic is poorly tolerated. If pain is still uncontrolled at this stage, referral for a specialist palliative care opinion or to a pain clinic is advisable

Corticosteroids (for example, dexamethasone 8 mg daily) may be used to reduce inflammation and oedema around a tumour if these are causing nerve compression

Tricyclic antidepressants—The analgesic effect of tricyclics is independent of any antidepressant effect. Mixed reuptake inhibitors such as amitriptyline seem to be more effective analgesics than the selective serotonin reuptake inhibitors. The starting dose should be low (such as amitriptyline 10–25 mg at night) and then titrated upwards on a weekly basis until pain control improves or side effects become intolerable. An analgesic response has been found with amitriptyline within the range 25–75 mg, but, as the dose increases, so does the frequency of unwanted effects (the evidence of analgesic activity is much less strong for drugs other than amitriptyline)

Anticonvulsants—Doses should start low and be titrated upwards. Sodium valproate (200 mg twice daily up to 1600 mg a day) is often better tolerated than carbamazepine (200 mg at night up to 400 mg twice daily)

Antiarrhythmic drugs—These are reserved as second or third line drugs, when treatment with antidepressant or anticonvulsant, or both, has failed. Mexiletine (50-200 mg thrice daily) is usually the first choice in this class

Corticosteroids (for example, dexamethasone 8 mg daily) may be used to reduce inflammation and oedema around a tumour if these are …