MAJOR — Use With Caution
DANGEROUS — avoid combining serotonergic herbs with DXM
Evidence level: MODERATE
Taking DXM cough medicine with St. Johns Wort risks serotonin syndrome.
St. Johns Wort increases serotonin via multiple mechanisms. DXM is serotonergic. Combined use risks serotonin syndrome.
Stop St. Johns Wort if you need DXM, or use DXM-free cough medicine.
Take Dextromethorphan as prescribed. St. Johns Wort can typically be taken with a meal at a different time. As a general rule, space botanicals 1-2 hours from prescription medications. St. John's Wort is the most interaction-prone botanical — it affects dozens of drugs via CYP enzyme induction. Always inform your prescriber about herbal supplements.
Concurrent SSRI/SNRI use, high doses of either substance
Agitation, confusion, rapid heart rate, sweating, muscle twitching, hyperthermia
Always tell your doctor about herbal supplements.
Discuss safer alternatives with your healthcare provider. They can recommend substitutions based on your specific health goals while minimizing interaction risks. Always bring a complete list of everything you take to your appointments.
Taking DXM cough medicine with St. Johns Wort risks serotonin syndrome.
Take Dextromethorphan as prescribed. St. Johns Wort can typically be taken with a meal at a different time. As a general rule, space botanicals 1-2 hours from prescription medications. St. John's Wort is the most interaction-prone botanical — it affects dozens of drugs via CYP enzyme induction. Always inform your prescriber about herbal supplements.
Agitation, confusion, rapid heart rate, sweating, muscle twitching, hyperthermia
Discuss safer alternatives with your healthcare provider. They can recommend substitutions based on your specific health goals while minimizing interaction risks. Always bring a complete list of everything you take to your appointments.
Always tell your doctor about herbal supplements.
Or browse the full interaction database (121,000+ pairs).