Life-Threatening Adverse Reaction after Self-Initiated, Off-Label Use of High Dose Nicotinamide for the Treatment of Friedreich’s Ataxia

Abstract

A 40-year old woman, previously known for Friedreich's ataxia, presented with shock, profound lactic acidosis and hepatic failure after ingestion of a high dose of nicotinamide, the amide form of vitamin B3. On her own initiative, she was taking up to 4.4 g per day of nicotinamide, after having learned the results of a phase 2 study suggesting a potential benefit in Friedreich's ataxia. The outcome was good with supportive care and withdrawal of nicotinamide. LEARNING POINTS• High-dose nicotinamide can cause life-threatening shock, lactic acidosis and hepatic failure.• Extensive use of experimental treatments can lead to unexpected, severe adverse reactions, even with apparently safe over-thecounter products.• Vulnerable patients with orphan diseases may self-initiate hazardous treatment which is still under investigation.