WHO has issued Medical Product Alert N°4/2025 after six lots of FENTANILO HLB (fentanyl citrate) were found contaminated in Argentina. The affected injection is used for peri‑operative analgesia and in intensive care. According to the alert, laboratory testing detected drug‑resistant Klebsiella pneumoniae and Ralstonia pickettii, creating a high risk of severe bloodstream infections among exposed patients. Argentina’s regulator (ANMAT) recalled implicated lots and previously suspended manufacturing activities at a producer due to serious good‑manufacturing‑practice failures. WHO advises clinicians and facilities to immediately quarantine and remove suspect stock, report adverse events to national authorities, and procure alternatives from authorised suppliers. Although the contaminated lots were identified in Argentina, WHO warns the products may have circulated elsewhere and requests vigilance and notifications if detected in other markets. The agency urges strengthened pharmacovigilance and supply‑chain checks until all recalled products are confirmed removed. (Source: WHO)