Over-the-counter analgesics: a toxicology perspective.
The decision to use any analgesic is a balance of benefit and risk. In the case of analgesics, it is important to balance the therapeutic benefit against both the risk in therapeutic use and the risk (and ease of treatment) in overdose. Paracetamol in therapeutic dose carries little risk of adverse events. Less than 0.1% of the estimated 30 million paracetamol users in the United Kingdom attend hospital with a paracetamol overdose each year, and approximately 200 people die, most of whom presented late or did not receive the antidote, N-acetylcysteine, within 12 hours. Nonsteroidal anti-inflammatory drugs (NSAIDs) have greater adverse effects in therapeutic use than paracetamol but also have a lower incidence of severe features or death in overdose. There is no antidote available for NSAID poisoning. Aspirin carries both significant adverse effects in therapeutic dose and a substantial risk in overdose, for which there is no antidote. Its risk–benefit profile is probably the poorest of all analgesics currently available over-the-counter (OTC); this is reflected in current trends both in analgesic use and overdose figures. Although a number of options to reduce deaths from poisoning by OTC analgesics have been considered, few are practical, and all must take account of the public health benefits provided by these drugs. A perspective should be retained that the vast majority of the population in Australia, the United States, the United Kingdom, and Denmark derive therapeutic benefit from OTC analgesics and do not take them in overdose. The majority of those who do take overdoses come to little or no harm. Management of serious poisoning by paracetamol, aspirin, or NSAIDs remains a medical challenge.