Key takeaways
Diphenhydramine (Benadryl) and pseudoephedrine (Sudafed) are both over-the-counter medications, but they have several differences. Diphenhydramine is an antihistamine used to treat allergies, common cold symptoms, and occasional sleep problems. It works by blocking histamine, which helps reduce sneezing, itching, and runny nose, but it can make you very sleepy. On the other hand, pseudoephedrine is a decongestant that relieves nasal and sinus congestion by narrowing blood vessels in your nose and sinuses. Unlike diphenhydramine, pseudoephedrine is non-drowsy and can actually make it hard for you to sleep if taken too close to bedtime. Diphenhydramine is available in various forms like tablets, capsules, and liquid, while pseudoephedrine comes in immediate-release and extended-release tablets, as well as liquid form for children. Both medications have generic versions available. Diphenhydramine is generally safe for children as young as 6 for allergy and cold symptoms, but not for sleep, whereas pseudoephedrine can be used by children as young as 4 in liquid form. Diphenhydramine should not be used long-term due to risks like memory problems. For this reason, it's generally best to avoid diphenhydramine in adults 65 years and older. Pseudoephedrine can raise blood pressure and heart rate, making it unsuitable for people with certain health conditions.
