What is serotonin syndrome?
Some medicines increase the amount of serotonin (a brain chemical called a neurotransmitter). Combining these medicines with other medicines or illegal drugs that also increase serotonin can cause a serious reaction called serotonin syndrome or serotonin toxicity. Avoid combinations of the medicines listed in the table below.
Symptoms of serotonin toxicity include:
Severe cases of serotonin syndrome may be fatal. Get medical care urgently if you think you are having this reaction.
Do not take any of the medicines below together unless you are under careful medical supervision.
|Category of medicine
||Active ingredient (with some brand name examples)
||All antidepressants, except reboxetine and agomelatine
||Linezolid (e.g. Zyvox)
||St John’s wort
|Cough and cold medicines
||Dextromethorphan (in many cough and cold medicines, e.g. Benadryl, Dimetapp)
||Sumatriptan (e.g. Imigran, Sumagran, Sumatab, Suvalan)
Rizatriptan (e.g. Maxalt)
Naratriptan (e.g. Naramig)
Eletriptan (e.g. Relpax)
Zolmitriptan (e.g. Zomig)
||Lithium (e.g. Lithicarb, Quilonum)
|Parkinson’s disease medicines
Selegiline (e.g. Eldepryl, Selgene)
|Strong pain medicines
||Fentanyl (e.g. Actiq lozenge, Denpax patches, Durogesic patches)
Tramadol (e.g. Lodam capsules, Durotram, Tramal, Tramedo, Zydol)
|Weight loss medicines
||Phentermine (e.g. Duromine, Metermine)
Sibutramine (e.g. Ectiva, Reductil)
||Buspirone (e.g. Buspar), for anxiety
Tryptophan (an amino acid)
Dexamphetamine, for ADHD or narcolepsy
Do not take any of the medicines in the table above if you are taking another medicine called a monoamine oxidase inhibitor (MAOI), and wait 14 days after stopping an MAOI before taking any of these medicines. Taking them with an MAOI or taking it too soon after stopping an MAOI may cause serotonin syndrome. MAOI medicines include:
- phenelzine (Nardil), an antidepressant
- tranylcypromine (Parnate), an antidepressant
- selegiline (Eldepryl, Selgene), for Parkinson’s disease.
Read more about how medicine interactions can happen.
Antidepressants and illegal drugs don’t mix!
Taking illegal drugs such as ecstasy, cocaine, amphetamines (speed) or LSD (acid) with an antidepressant increases the risk of serotonin toxicity, which can be fatal. If you have a problem with drugs, you may benefit from counselling as this can help you recover from depression.