The Role of Patient‐ and Drug‐Related Factors in Oral Minoxidil and Pericardial Effusion: Analyses of Data From the United States Food and Drug Administration Adverse Event Reporting System

BACKGROUND: While oral minoxidil (OM) has been associated with pericardial effusion (PE), its etiology is presently inconclusive. AIMS: We characterized patient- and drug-related factors across reports from the United States Food and Drug Administration Adverse Event Reporting System (FAERS) for PE and OM. METHODS: Our observation period spanned 18.5 years. Parametric and non-parametric analyses were used; we stratified our findings according to two groups of adverse events (AEs), namely, PE and all other AEs. RESULTS: Across reports of OM (n = 2747), positive dechallenge (complete resolution or subsiding of AE upon discontinuation of OM) was significantly more likely to occur for PE than for all other AEs (p < 0.05). Furthermore, OM was significantly more likely to play a primary role in PE compared to all other AEs (p < 0.05). The proportion of men was significantly higher in OM reports of PE than in OM reports of all other AEs (p < 0.05). We also identified six reports of PE and topical minoxidil. CONCLUSIONS: Though findings from spontaneously reported data never prove causality, our findings on dechallenge and purported role may suggest one. There were no reports of PE at a dose < 2.5 mg/day, 2/35 reports at 2.5 mg/day, and 8/35 reports at 5 mg/day. Overall, the results of statistical analyses support that the relationship between OM and PE is dose independent. Caution should also be taken when applying minoxidil topically because of reports of PE associated with this route of administration.