The treatment of cough is directed by the cause. You may get symptomatic relief from: over-the-counter (OTC) cough medicines containing guaifenesin and/or dextromethorphan, drinking lots of water, inhaling steam, and using cough lozenges. Sinus problems and postnasal drip: Use of decongestants such as pseudoephedrine (Sudafed) or antihistamines such as diphenhydramine (Benadryl) may improve symptoms of post nasal drip. Inhaled nasal steroids are very effective in treating allergic rhinitis (hay fever), a common cause of cough. Additionally, other nasal inhalers like ipratropium bromide (Atrovent) can relieve post nasal drip. Antibiotics may be prescribed if the cause is determined to be sinusitis.