Will benadryl (diphenhydramine) regular strength make my asthma worse?

Possibly : Benadryl (diphenhydramine) is an antihistmaine. If your asthma trigger is allergic, then it would be helpful. However side effects-sleepiness, dry nasal passages, etc. Are very comon. Claritin which has less side effects would be a better choice. Remember that a drug like Benadryl (diphenhydramine) can "thicken" lung secretions and make them harder to cough up. Check with your physician before anything.

Use with caution: The antihistamine products like benedryl will thicken your mucous secretions which can be a problem for those on the margins with asthma. Asthma patients tend to have problems with excess secretions already & thickening them lakes it harder for them to be cleared from the airways. Benedryl can often be used during periods of good control, but i avoid it during flares.