Baclofen-induced manic symptoms: case report and systematic review

Abstract

Background: The gamma-aminobutyric acid type B receptor agonist baclofen is approved for spasticity and is used off-label for diverse types of addictive disorders, notably alcohol dependence. Baclofen may induce numerous neuropsychiatric adverse drug reactions, including behavioral disinhibition. However, this precise adverse drug reaction has never been assessed using either a validated causality algorithm or a scale for manic symptoms.

Methods: We report a case of a 49-year-old male patient who exhibited de novo mania during treatment with baclofen for alcohol dependence. Symptoms were evaluated using the Young Mania Rating Scale, and the causality of baclofen was determined using the Naranjo algorithm. This case was also compared with other cases of baclofen-induced mania through a systematic literature review.

Results: Mr. X, taking 180 mg/d of baclofen, presented with mania and scored 24 of 44 on the Young Mania Rating Scale, and the imputability of baclofen was "probable" using the Naranjo algorithm (8 of 13). In addition, 4 other cases of baclofen-induced mania were reported in the literature; 3 cases had a bipolar I disorder history. Baclofen-induced manic symptoms occurred mostly during the dose-escalation phase.

Conclusion: Baclofen-induced manic symptoms may appear in patients with or without bipolar disorder. Particular attention is required during the dose-increase phase and in patients with a history of mood disorders.