Abstract

Perhexiline is an antianginal medication used in refractory disease. Despite being highly efficacious, it is seldom prescribed due to its risk of neurotoxicity and hepatotoxicity. These adverse effects are often linked to high plasma concentration in patients with impaired metabolism, identified through therapeutic drug monitoring. In this report, a man in his 70s developed hepatotoxicity, lower limb weakness, poor coordination and reduced mobility following 6 months of perhexiline use, leading to recurrent falls and multiple hospitalisations. Extensive testing ruled out other causes of the patient’s symptomatology. During his third hospital presentation, elevated serum perhexiline levels confirmed toxicity. Cessation of perhexiline led to a marked improvement in liver function, mobility and function, allowing for the patient to be discharged home. This case underscores the critical role of therapeutic drug monitoring and the need to consider adverse drug reactions in vulnerable older patients.