How Passionflower interacts with OTC products causing drowsiness

Interaction type: Interactions

Interaction rating: Potential/Theoritical

Animal studies report that passionflower may cause sedation, which may enhance the effects of these medications and possibly the dose needed for treatment. Use with caution. (1) (2)

These drugs include diphenhydramine,chlorpheneramine


  1. Aoyagi N, et al. Studies on Passiflora incarnata Dry Extract. I. Isolation of Maltol and Pharmacological Action of Maltol and Ethyl Maltol. Chem Pharm Bull. (Tokyo). May1974;22(5):1008-13.
  2. Speroni E, et al. Neuropharmacological Activity of Extracts from Passiflora incarnata. Planta Med. Dec1988;54(6):488-91.