Beyond use date of drugs

Context: There are standards that allow establishing the microbiological and physicochemical stability of a medicine; however, beyond use date of drugs depends not only on these criteria, but also on individual institutional characteristics. The multiple factors that involve the allocation of the stability of a medication, if not properly articulated, can lead to therapeutic failures and adverse events in patients. Aims: To design an algorithm to determine the stability beyond use date of a drug in a high complexity healthcare institution. Methods: Pharmaceutical form, packaging, and administration route were defined for each drug. Physicochemical and microbiological stability were assigned to each product. An algorithm was built with the collected information. The stability beyond use date was the shortest time registered between microbiological and physicochemical stability, however, the information of the manufacturer was respected. Results: A total of 938 drugs were analyzed, which 606 (64.6%) were considered as single-dose and 332 (35.4%) as multiple-dose. The mean reason to assign a drug as a single-dose with 90.9% was pharmaceutical form unable to storage, tablet, capsule, and ampoule the most frequent. The main cause with 54.4% to assign a drug as multiple-dose was synthetic products with liquid and semisolid pharmaceutical forms whose packaging materials were allowed to storage after its first use. Conclusions: An algorithm was designed, which can assign the stability beyond use date of drugs using an easy and reliable, generating a more safety use inside the institution.