Question: Which adverse clinical consequences associated with the use of quinidine resulted in the U.S. Food and Drug Administration prohibiting the off-label use of this drug to treat leg cramps?
Answer: The cited reference notes “Quinidine causes a drug-dependent, antibody-mediated thrombotic microangiopathy. The occurrence of arrhythmias, thrombocytopenia and thrombotic microangiopathy in association with quinidine intake prompted the Food and Drug Administration to prohibit its off-label use to treat leg cramps. (Dhaliwal G et. al. Case 36-2017: A 30-year-old man with fatigue rash, anemia and thrombocytopenia. 2017 NEJM 377(21):2074-2083).