Over-the-counter (OTC) drugs are medications you can buy without a prescription. These medications are sold in pharmacies, grocery stores, and convenience stores. This is not to say that OTC drugs are harmless. Any drug can be dangerous if misused. Taking more than one OTC drug at a time or mixing OTC drugs and prescription drugs can be harmful or reduce effectiveness. It is best to consult your pharmacist or doctor when taking OTC drugs. Also, combining alcohol with any drug can be dangerous and even fatal. The most common OTC drugs are pain relievers, cold and cough medications, antihistamines, antacids, and laxatives. These drugs can be very helpful, short-term solutions when used as instructed.

Pain Relievers (analgesics)
People use pain relievers or analgesics to relieve headaches, tooth pain, menstrual cramps, and aches from colds or flu. There are three major kinds of OTC analgesics: acetaminophen (Tylenol®), ASA (Aspirin®), and non-steroid anti-inflammatory drugs (for example, ibuprofen found in Advil®).

Mild opioid painkillers such as codeine are often combined with ASA and acetaminophen to increase pain relief. You can buy some of these stronger pain relievers without a prescription, but are kept behind the counter and are available only through a pharmacist.

Cough and Cold Medications
These drugs are meant to relieve the symptoms of colds and flu, such as coughing, stuffy nose, aches, and fever. Some cold and allergy medications have ingredients that can be harmful when taken in large does. Effects can include nervousness, stomach upset, dizziness, and in rare cases, heart palpitations, headache and breathlessness.

Antihistamines
These medications are most often used to lessen or prevent allergic reactions. Large quantities of antihistamines can be harmful, especially if you take them with other depressants such as alcohol and codeine.

At recommended doses, antihistamines can cause drowsiness, dizziness, mild problems with concentrating, and sometimes nightmares, unusual excitement and nervousness (more common in children than adults), mild euphoria, blurred vision, ringing in the ears, and tremors.

Higher doses may make these effects stronger and, at very high doses, the effects can be severe. Symptoms include confusion, muscle twitching, hallucinations, tremors, flushed or red face, irregular heartbeat, feeling faint, and, rarely, convulsions. Large quantities of antihistamines can be dangerous for young children. All medications should be stored safely out of reach.

Antihistamines are also the main ingredients in many OTC sleeping aids. Dimenhydrinate (Gravol®) is used to prevent motion sickness.

Antacids
People use antacids to relieve pain from heartburn or an ulcer. Antacids should be used for a short time only, and can interfere with the absorption of other drugs. If you are taking other medications, check with your doctor or pharmacist before taking an antacid.

Laxatives
Laxatives are used for occasional constipation when bowel movements are infrequent or difficult. The most serious side effect of laxative use is developing a dependence on them for normal bowel function. Laxatives should not be given to children except on the advice of a doctor.

Source: Alberta Alcohol and Drug Abuse Commission

Relevant Links

A Parent's Guide to Preventing Teen Cough Medicine Abuse
Convenience-Store High: How Ordinary Cough Medicine is Being Abused for its Mind-Altering Effects - SAMHSA's National Clearinghouse for Alcohol and Drug Information
Dextromethorphan - JustFacts.org
Give 'Em the Facts: Prescription & Over-the-Counter Drug Abuse - SAMHSA's National Clearinghouse for Alcohol and Drug Information
Hallucinogens and Dissociative Drugs - National Institute on Drug Abuse
What Every Parent Needs to Know About Cough Medicine Abuse - Partnership for a Drug-Free America