Too much serotonin activity, usually from combining drugs that each raise it - an SSRI plus a triptan, tramadol, St John's Wort, dextromethorphan, or MAOIs - or from a dose jump.
The NHS symptom list: fast heartbeat, sweating, shaking, twitching muscles, confusion or agitation - plus high temperature and diarrhea in the classic picture. It starts within hours of the trigger. Mild cases settle when the drug is stopped; severe cases (very high temperature, rigid muscles, seizures) are emergencies. Prevention is one habit: every prescriber and pharmacist knows your full list before adding migraine, pain, cough, or herbal products. Agitation plus sweating plus twitching within hours of a new combination is a same-day call. Pymander is a free AI doctor, 24/7 by text, and can check a combination first.
What to do
Common questions
What is serotonin syndrome?
Serotonin syndrome is what happens when serotonin activity in the nervous system overshoots - almost always from combining medicines that each raise it: an SSRI or SNRI plus a triptan for migraine, plus tramadol, plus St John's Wort, plus certain other drugs (MAOIs, linezolid, dextromethorphan in cough syrup, even lithium) - or from a dose increase or overdose of one. It is rare but serious. The NHS symptom list for sertraline names it directly: a rare but serious condition causing a fast heartbeat, sweating, shaking, twitching muscles, and feeling confused or agitated - add high temperature, diarrhea, and dilated pupils to the classic picture. The timeline is fast: symptoms usually start within hours of the trigger - a new drug added, a dose raised. Mild cases settle when the triggering drug is stopped; severe cases - very high temperature, rigid muscles, seizures - are medical emergencies. The prevention is one habit: every prescriber and pharmacist should know your full list, especially before adding migraine, pain, cough, or herbal products to an antidepressant - the dangerous pairs are rarely obvious. If you develop agitation, sweating, and muscle twitching within hours of a new serotonergic combination, treat it as urgent: same-day medical advice, emergency care if severe. Pymander is a free AI doctor, 24/7 by text, that can check a combination before you take it.