Question: does benadryl affect the prostate?
Answer: Decongestants and Antihistamines Such drugs, known as adrenergics, can worsen urinary symptoms by preventing muscles in the prostate and bladder neck from relaxing to allow urine to flow freely. Antihistamines, such as diphenhydramine (Benadryl, generic), can also slow urine flow in some men with BPH.