What Are Over-the-Counter Drugs?

Over-the-counter, or OTC, drugs are medicines you can buy at a pharmacy without a doctor's prescription and, for most people, these less powerful medicines that can tide them through a casual cough, cold or other minor ailment such as allergies, yeast infections or childhood problems like head lice. Although OTC medicines are safe, it is important to read the labels and to use the correct dosage.

Pain Relievers

• An OTC medicine can help relieve headache.

  The two types of pain relievers available over-the-counter are acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs). Acetaminophen works by targeting those parts of the brain that receive pain messages and by controlling the temperature of the body. NSAIDs work by lessening the amount of prostaglandins your body produces. These substances irritate nerve endings and, thus, cause pain. OTC pain relievers also help to reduce fevers and can lessen pain caused by such problems as arthritis and backache. NSAIDs help to reduce swelling or inflammation.

Cough Medicines and Decongestants

• Cough suppressants help persistent coughs.

  Two kinds of cough medicines are available over-the-counter: antitussives and expectorants. Dextromethorphan is the antitussive or cough suppressant contained in most common brands people use to help control their coughs. Guaifenesin is the expectorant used in OTC products. Sometimes the cough suppressant and the expectorant are combined and available OTC in this formula. A common side effect of OTC cough syrups is usually sleepiness.

Antihistamines

• OTC antihistamines help to relieve allergy symptoms such as sneezing, drippy noses, watery eyes and hives. They are often available in combination with other OTC drugs, such as cough or cold medicines. When an antihistamine tablet is swallowed, it blocks histamines from causing these symptoms. Some antihistamines called first-generation antihistamines work by targeting the area of the brain that controls nausea and vomiting, so this type of drug is often used to combat motion-sickness.

Antacids

• Indigestion and heartburn can be alleviated by taking an antacid.

  Many people suffer from heartburn and indigestion and purchase antacids over-the-counter. This popular remedy neutralizes stomach acids so a person feels a quick sense of relief. Some antacids contains H2 blockers and proton pump inhibitors which are slower to work than other types of antacids, but relieve heartburn and indigestion for a longer time. The H2 blockers and proton pump inhibitors work by reducing the amount of acid the stomach makes. Taking antacids may cause such side effects as headaches, nausea, constipation or diarrhea.