Adverse effects from counterfeit and mislabeled medicine containing tapentadol and carisoprodol

Abstract

Key Clinical MessageWhen self‐administration with counterfeit or mislabeled medicine is suspected, comprehensive laboratory analysis should be preferred over immunoassay screening to avoid false negative results. Carisoprodol, which was formerly a popular muscle relaxant drug in many countries, has reappeared on illegal drug markets, and may cause an itching, purple‐colored rash, even after a single dose.