Fatal drug combination sparks alert as 'rhino tranq’ spreads across US

Health and government officials are warning of a potential deadly substance in the illegal drug supply.

The Centers for Disease Control and Prevention (CDC) and the White House Office of National Drug Control Policy (ONDCP) issued a health advisory on Thursday about reports of medetomidine being detected in fentanyl.

Also known as "rhino tranq," "mede" or "dex," medetomidine is a veterinary sedative that causes severe, prolonged sedation. Classified as an alpha-2 agonist, it acts on...