Severe cutaneous adverse reactions associated with systemic ivermectin: A pharmacovigilance analysis

Despite poor evidence, the antiparasitic ivermectin has been advocated as a potential COVID-19 therapy. This has led to a rise in calls to poison-control centers by people self-medicating with ivermectin, which is sold over the counter for veterinary uses. We aimed to investigate the association between severe cutaneous adverse reactions (SCARs) and ivermectin. Postmarketing data from the FDA Adverse Event Reporting System (FAERS), gathered between 2014 and 2021, was employed to detect disproportional signals of SCARs following systemic ivermectin therapy. The reporting odds ratio (ROR) was used to quantify the strength of association, while adjusting for age, sex, and region. The search yielded 517 reports of systemic ivermectin (median age 54 years, 46.8% female), of which 25 (4.8%), 81 (15.7%), and 411 (79.5%) were classified as SCARs, nonsevere cutaneous adverse events (AEs), or noncutaneous AEs, respectively. The regional distribution differed between SCAR reports (32.0% from Africa and 12.0% from North America) compared with other AEs, which originated from North America in over half of cases. The most common SCARs were toxic epidermal necrolysis (seven cases), Stevens–Johnson syndrome (seven cases), and drug reaction with eosinophilia and systemic symptoms (four cases). Five SCAR cases (20.0%) resulted in death and 12 (48.0%) lead to hospitalization. There was a strong safety signal for any SCAR (adjusted ROR 3.34, 95% confidence interval [CI] 2.17–5.12) and toxidermias (adjusted ROR 7.08, 95% CI 4.23–11.84). This study suggests that ivermectin is associated with SCARs on rare occasions. Dermatologists should be aware of this given the increase in ivermectin misuse.