Some over the counter decongestants are oxymetazoline (Afrin, Dristan, Vicks, Sinex), phenylephrine (Sudafed PE, Suphedrin PE) and pseudoephedrine (Silfedrine, Sudafed, Suphedrin), lists WebMD. Pharmacies typically keep decongestants containing pseudoephedrine behind the counter.
Patients take decongestants in oral form or in nasal sprays or drops, states Drugs.com. These medicines clear the nose and sinuses of mucous by reducing swelling in the nasal passages and sinuses. This action relieves congestion and makes breathing easier. WebMD advises people with glaucoma, high blood pressure, heart conditions, thyroid problems, enlarged prostate or diabetes to check with a doctor before taking an over the counter decongestant.