Use and potential risks of over-the-counter analgesics

We investigated the use of prescription and non-prescription (over-the-counter, OTC) analgesics and the associated risks in elderly patients with multiple morbidities. Pain medication use was evaluated from the baseline data (2008/2009) of the MultiCare cohort enrolling elderly patients with multiple morbidities who were treated by primary care physicians (trial registration: ISRCTN89818205). We considered opioids (N02A), other analgesics, and antipyretics (N02B) as well as nonsteroidal anti-inflammatory drugs (NSAIDs; M01A). OTC use, duplicate prescription, dosages, and interactions were examined for acetylsalicylic acid, diclofenac, (dex)ibuprofen, naproxen, and acetaminophen. Of 3,189 patients with multiple morbidities aged 65-85 years, 1,170 patients reported to have taken at least one prescription or non-prescription analgesic within the last 3 months (36.7 %). Of these, 289 patients (24.7 % of 1,170) took at least one OTC analgesic. Duplicate prescription was observed in 86 cases; 15 of these cases took the analgesics regularly. In two cases, the maximum daily dose of diclofenac was exceeded due to duplicate prescription. In 235 cases, patients concurrently took a drug with a potentially clinically relevant interaction. In 43 cases (18.3 % of 235) an OTC analgesic, usually ibuprofen, was involved. About one third of the elderly patients took analgesics regularly or as needed. Despite the relatively high use of OTC analgesics, the proportions of duplicate prescription, medication overdoses, and adverse interactions due to OTC products was low.