Introduction: Carbamazepine is a commonly prescribed anticonvulsant and mood-stabilizing drug. While its toxicity profile is well-documented, rare complications are infrequently reported. This case report aims to highlight an unusual presentation of acute carbamazepine toxicity leading to foot drop.

Case presentation: A 25-year-old female with a history of depression presented to the emergency department with confusion, ataxia, and generalized weakness after an intentional overdose of 40 grams of carbamazepine. Initial serum carbamazepine levels were significantly elevated at 70 mcg/mL (therapeutic range: 4-12 mcg/mL). Despite supportive care and administration of activated charcoal, the patient developed an acute unilateral foot drop on the seventh day of hospitalization. Neurological examination revealed decreased dorsiflexion strength and sensory deficits in the L4-L5 dermatomes. Electromyography confirmed peripheral neuropathy consistent with carbamazepine-induced neurotoxicity.

Conclusion: This case underscores the importance of vigilance for atypical neurological complications in patients with carbamazepine toxicity. Clinicians should consider carbamazepine-induced peripheral neuropathy in the differential diagnosis of acute foot drop, particularly in the context of overdose.