According to WebMD, there are no pharmacological interactions between Tylenol and Benadryl, thus the two medications can be used concurrently. However, a personal physician or pharmacist should always be notified so that they can update the drug list.
Tylenol is the brand name for the over-the-counter pain medication and fever reducer acetaminophen. Benadryl is the brand name for the over-the-counter allergy medication diphenhydramine. By itself, there are no documented pharmacological interactions between the two drugs.
Although there are no known interactions, if a patient is also taking other medications, these additional medications may result in a drug interaction where one did not exist previously. Therefore, it is crucial that a patient’s doctor always has an accurate list of medications being taken.