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A 25-year-old male asked:

I took 10 mg loratadine (non drowsy 24 hr claritin) 8 hours ago for my allergies. it didnt work and im trying to go to bed so i was wondering if it was safe to take 25 mg diphenhydramine hcl (benadryl) since it does make you drowsy?

2 doctor answers3 doctors weighed in
Dr. Edward Kuhnley
Child Psychiatry 46 years experience
Likely safe: Interaction: Diphenhydramine will increase the level or effect of loratadine by affecting hepatic enzyme CYP2D6 metabolism. It is considered Minor with Significance Unknown. Best regards for good health.
Dr. James Ferguson
Pediatrics 47 years experience
Expected pattern: Loratadine is one of several non-drowsy antihistamines that take up to a day to achieve a blood level in your system to reach peak effect. Daily use maintains that level. Diphenhydramine works differently achieving peak effect in an hour or so but leaving the body sooner. I see no reason not to use both as their side effect profile does not overlap.The drowsiness would be the same clinically.

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Last updated Sep 20, 2020


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