I am sick right now I just have cold symptoms, sneezing, runny nose, coughing, etc... I took some Sudafed 12 hour with the active ingredient, Pseudoephedrine. Since I took it my nose is running out of control, I am sneezing non stop, it's like someone opened up a faucet (not to be gross). This might be nice if I could lay in bed and blow my nose all day, but I have a ton of homework to get done. Would there be a problem with me taking Tylenol Allergy (active ingredient Diphenhydramine). This stuff is supposed to: "It prevents sneezing; itchy, watery eyes and nose; and other symptoms of allergies and hay fever." while Pseudoephedrine is supposed to: "It constricts (shrinks) blood vessels (veins and arteries). This reduces the blood flow to certain areas, which decreases swelling and allows nasal and respiratory (breathing) passages to open up." They seem like they might clash, so I thought I should ask if it is cool to take both. Any suggestions? It looks like Claritin-D uses a decongestant/antihistamine combo... so I'm thinking it is ok.