This class of medication can be purchased without a prescription. Which medications require prescriptions and which do not varies widely from country to country. Common examples of OTC medications in the United States include ANALGESICS (aspirin, Tylenol®), cough and cold products (Sinutab®, Drixoral®), allergy medications (Benadryl®, Tavist), gastrointestinal products (Maalox®), antidiarrheals (Imodium®), and nicotine replacements (e.g., Nicorette® Gum, Nicoderm® Patch). Recently, a number of medications that previously were sold only by prescription have been made available over-the-counter. These include medications that block the production of gastric acid to relieve heartburn (Axid AR®, Tagamet HB 200®, Zantac 75®) and nicotine gum (Nicorette CQ®) and the nicotine patch (Nicotrol®, Nicoderm CQ®) for smoking cessation.

Prescription medications are labeled with patient-specific instructions determined by a physician whereas OTC products provide general information for use by consumers. OTC products are drugs, and as such they may cause side effects...