Drugs for neuropathic pain

The patient is a 63 year old freelance editor with type 2 diabetes diagnosed about five years ago that is relatively well controlled with insulin. He has early signs of retinopathy, with normal kidney function and electrocardiogram. Lipid values are normal with diet and atorvastatin 20 mg/day. He developed autonomic and peripheral neuropathy a few months ago, and now experiences postural hypotension and burning pain and clumsiness in his feet. His pain makes concentration and falling asleep difficult. He asks his general practitioner for painkillers to help him continue working. Neuropathic pain can have many causes (box 1),1 with diabetic neuropathy among the commonest. The International Association of the Study of Pain defines neuropathic pain as “pain caused by a lesion or disease of the somatosensory system.”2 This article focuses on drugs for treating neuropathic pain, mainly antiepileptics and antidepressants, including those used off-label in the UK (box 2). National Institute for Health and Care Excellence (NICE) guidance1 recommends offering a choice of amitriptyline, duloxetine, gabapentin, or pregabalin as initial treatment, with switching between these drugs if pain relief is not obtained or the treatment not tolerated. Successful clinical management requires balancing the benefits and adverse effects of available drugs, lifestyle interventions, and treating the underlying cause if possible. Possible comorbidities (anxiety, depression) need to be considered when choosing the best treatment for an individual patient. #### Box 1: Common conditions that might cause neuropathic pain Neuropathic pain is defined as peripheral or central depending on the site of injury. The central nervous system is always involved in the processing of pain. Some neuropathic pains may be mixed—that is, they have both peripheral and central components (such as postherpetic neuralgia, post-amputation pain1). ##### Peripheral pain ###### Common