Stephen asked
I started self-medicating with St. John's Wort. Can I take Benadryl once in awhile with it or do they interact with each other?
Answer
There is no known drug interaction between St. John’s Wort and Benadryl. However, it is important to be aware that both may cause sedation and dizziness. It would be prudent to take St. John's wort without other medications, at least initially, until you know how it affects you.
St. John's Wort
St. John’s Wort is a natural medicine that is typically used as an antidepressant. It is one of the most studied herbs and has shown superior efficacy versus placebo for the treatment of depression. In fact, many studies have reported it has equal effectiveness to many popular SSRI medications, like Prozac (fluoxetine).
Side effects of St. John’s wort include:
- Stomach upset
- Sedation
- Dizziness
- Headache
- Fatigue
Benadryl
Benadryl is a "first-generation" antihistamine that is used to treat allergic reactions and is frequently used as a sleep aid. It has a relatively short duration of action (~4 to 8 hours) and is known for its sedating properties.
Benadryl begins to work about 20 to 30 minutes after taking by mouth and maximum blood concentrations are reached after 1 to 2 hours. The duration of action varies by individual but generally lasts 4 to 6 hours. Benadryl is generally well tolerated but can cause the following side effects:
- Sedation
- Dizziness
- Respiratory depression (rare)
