Potential role of pregabalin in the treatment of lithium-induced tremor: a case report

Abstract

Pregabalin is a structural analogue of gamma-aminobutyric acid (GABA), one of the key inhibitory neurotransmitters in the brain. It is approved by the United States Food and Drug Administration (FDA) for the treatment of pain related to diabetic peripheral neuropathy, post-herpetic neuralgia, adjuctive therapy for partial onset seizures, and fibromyalgia (US FDA, 2007). Pregabalin has also shown efficacy in other conditions for which it is used off-label, including anxiety (Feltner et al. , 2008). The current report describes the first documentation of the usefulness of pregabalin in treating lithium-induced tremor. In the case described, pregabalin was prescribed as an anxiolytic to an in-patient with treatment-refractory major depressive disorder and generalized anxiety disorder; the beneficial effect on tremor was coincidental and unexpected. However, a pilot randomized, double-blind, placebo-controlled clinical trial demonstrated the efficacy of pregabalin in the treatment of benign essential tremor (Zesiewicz et al. , 2007) and a large multicentre trial (clinicaltrials.gov NCT00584376) is currently in process to evaluate its efficacy and safety for this indication. It is plausible that pregabalin may therefore have a unique role in the treatment of patients with lithium-induced tremor, particularly considering the frequent comorbidities of anxiety in patients treated with lithium (bipolar and major depressive patients). To our knowledge, there have been no published case reports of the use of pregabalin for lithium-induced tremor. Mr A was a 65-yr-old man with a history of major depressive disorder and generalized anxiety …