With gyms reopening and summer holidays on the horizon, many of us are trying to get into shape with workouts and dietary supplements. There are a wide range of dietary supplements available, some of which will have a medical validity and some will be taken as a way of aiding and promoting weight loss, contributing to a ‘healthier’ lifestyle.

5-HTP is a naturally occurring amino acid and chemical precursor as well as a metabolic intermediate in the biosynthesis of the neurotransmitters serotonin and melatonin. As well as an appetite suppressant it is used as over the counter antidepressant. In overdose 5-HTP can cause serotonin syndrome. The onset of clinical signs may be rapid (<30 minutes), with behavioural changes, gastrointestinal signs and increased neuromuscular activity.

Treatment, other that early emesis and activated charcoal – if safe to do this – is aimed at controlling pyrexia and convulsions. Ideally, diazepam (or barbiturates) can be used for agitation, tremors or convulsions, and it should not be necessary to scale up, although propofol CRI could be considered if required. Cyproheptadine is a non-specific serotonin antagonist and is the drug of choice for management of dogs with serotonin syndrome. IV fluids may be needed to maintain hydration and to assist, when cool fluids are used, in controlling hyperthermia.