Beyond clinical toxicology: protecting our poisoned patients

The immediate management of poisoned patients is a major activity in emergency departments and acute medical wards. This can mean the neglect of more detailed enquiry that would make clear the underlying cause of the poisoning and suggest ways to reduce the risk of repeated poisoning for the individual and more generally. The history and circumstances of poisoning may make the precipitants evident, but it is still important to consider what factors contributed. Here, we divide poisoning into unintentional and intentional, and suggest how these major groups may be subdivided. There is a need in unintentional poisoning to consider whether the patient has been poisoned because of their vulnerability, for example, resulting from dementia. Where a carer such as a parent or partner has committed an error, they too may be vulnerable. If the poisoning is a result of error by a clinical professional, then the question of clinical competence can arise. If the poisoning is deliberate, mental ill-health may have contributed, and the patient may not have capacity to make decisions. There may also be a conflict between what the patient wants and what the clinician deems to be in the patient's best interest, in which case it may be necessary to consider mental capacity. A systematic approach to these important questions can offer the best prospect for prevention of further poisoning for the individual. Broader attempts to prevent poisoning require good data on the causes and circumstances in which it occurs, but these are often lacking.