 [ Symptoms ] can i take benadryl while taking propranolol 20 mg [ Disease ] benadryl is safe to take while using propranolol there are not any dangerous interactions however propranolol does make some people drowsy and benadryl can make you drowsy as well i would suggest you get an antihistamine that does not cause drowsiness ask your pharmacist he or she can help you find one that is best for you