Amitriptyline-related peripheral neuropathy. Case report

Although amitriptyline is not usually regarded as toxic to the peripheral nervous system (PNS) and is even prescribed by some for neuropathic pain, there are sporadic reports of peripheral neuropathy following overdose or prolonged use of the drug. The scarcity of data leads us to report a case we have followed for 3 years clinically and electromyographically. A 54 year old man on oral amitriptyline 150 mg uninterruptedly for 2 years consulted us for lower limb paresthesias and was found on clinical examination to have reduced ankle jerks and mild distal global hypoesthesia. EMG yielded a pattern of sensorimotor neuropathy compatible with axonal disease in all four limbs. The history was unremarkable and the laboratory data were within normal limits. After discontinuation of amitriptyline therapy both the clinical and EMG pattern gradually normalized. We draw attention to the possible risk, infrequent though it is, of PNS neurotoxicity of a widely used drug reputedly harmless from this point of view.