I wheeze almost every night, even if i don't have colds. sometimes causing difficulty in breathing, other times bearable. what otc medicine to use?

Go see your doc: Sounds like you might have asthma. You need to go see your doctor ASAP so you can be diagnosed, and prescribed rescue and maintenance medication if it's needed. An OTC antihistamine might help if you have allergy-induced asthma (perhaps to molds that are more prevalent at night), but they won't help with an acute attack of shortness of breath, which can be life-threatening. Go see your doc!

See answer: Several considerations: YOU SHOULD CONSULT A PHYSICIAN TO see what your diagnosis is. Do you have symptoms only in the evening? At bedtime? Do they awaken you from sleep? Any cats or dogs at home? Any symptoms of GERD. The OTC inhaler Asthmanefrin contains racemic epinephrine and can relieve asthma but it's not as safe or as effective as the Rx Albuterol.Reports of more side effects than Albuterol

Asthma? Other?: Asthma is the most common explnation of such symptoms, but there are plenty of other possible causes, including several other bronchial, lung, and heart diseases. Some of them are dangerous, and self treatment OTC would be a big mistake. See a doctor for proper diagnosis and treatment.