Christian Leos-Alvarado, Clinical Laboratory Department, UMAE 71, Instituto Mexicano de Seguro Social (IMSS), Torreón, Coahuila, México
Rogelio Cázares-Tamez, Department of General Manager, BSH Laboratories, Monterrey, Nuevo León. México

Fentanyl is a very strong synthetic opioid used to treat severe pain. It is 50-100 times more powerful than morphine. However, the most recent cases of overdoses and deaths are related to illegally manufactured fentanyl.