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Overview of Over-the-Counter Drugs

By

Shalini S. Lynch

, PharmD, University of California San Francisco School of Pharmacy

Last full review/revision Jul 2019| Content last modified Jul 2019
Click here for the Professional Version
NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
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Over-the-counter (OTC) drugs are those available without a prescription.

OTC drugs enable people to relieve many annoying symptoms and to cure some diseases simply and without the cost of seeing a doctor. However, safe use of these drugs requires knowledge, common sense, and responsibility.

In addition to the substances such as aspirin and acetaminophen that people typically think of as OTC drugs, many other commonly available products are considered OTC drugs by the Food and Drug Administration (FDA). Some toothpastes, some mouthwashes, some types of eye drops, wart removers, first aid creams and ointments that contain antibiotics, and even dandruff shampoos are considered OTC drugs. Each country establishes which drugs are available OTC in that country.

Some OTC drugs were originally available only by prescription. After many years of use under prescription regulation, drugs with excellent safety records may be approved by the FDA for over-the-counter sale. The analgesic ibuprofen and the indigestion remedy famotidine are examples of such drugs. Often, the OTC version has a substantially lower amount of active ingredient in each tablet, capsule, or caplet than does the prescription drug. When establishing appropriate doses of OTC drugs, manufacturers and the FDA try to balance safety and effectiveness.

OTC drugs are not always better tolerated than similar prescription drugs. For example, the OTC sleep aid diphenhydramine can cause just as serious adverse effects as many prescription sleep aids, especially in older people.

Historical Background

At one time, most drugs were available without a prescription. Before the Food and Drug Administration (FDA) existed, just about anything could be put in a bottle and sold as a sure-fire cure. Alcohol, cocaine, marijuana, and opium were included in some over-the-counter (OTC) products without notification to users. The Food, Drug, and Cosmetic (FD&C) Act, enacted in 1938, gave the FDA some authority to issue regulations, but the act did not provide clear guidelines as to which drugs could be sold by prescription only and which could be sold over the counter.

An amendment to the FD&C Act in 1951 attempted to clarify the difference between OTC and prescription drugs and to deal with issues of drug safety. Prescription drugs were defined as compounds that could be habit forming, toxic, or unsafe for use except under a doctor's supervision. Anything else could be sold over the counter.

As noted by an amendment to the FD&C Act of 1962, OTC drugs were required to be both effective and safe. However, determining effectiveness and safety can be difficult. What is effective for one person may not be for another, and any drug may cause unwanted side effects (also called adverse effects, adverse events, or adverse drug reactions). There was no organized system in the United States for reporting the adverse effects of OTC drugs until 2007, when a new law became effective that required companies to report serious adverse events associated with OTC drugs (see OTC Products and Dietary Supplements).

Safety Considerations

Safety is a major concern when the Food and Drug Administration (FDA) considers reclassifying a prescription drug as OTC (over-the-counter). Most OTC drugs—unlike health foods, dietary supplements (including medicinal herbs) and complementary therapies—have been studied scientifically and extensively. However, all drugs have benefits and risks, and some degree of risk has to be tolerated if people are to receive a drug's benefits. Defining an acceptable degree of risk is a judgment call.

Reclassifying drugs as over-the-counter drugs

The following questions can help determine whether a drug is safe enough to be made available over the counter:

  • Has the drug been used for a long enough time so that any harmful effects are fully understood?

  • What harmful effects (including those from misuse) may the drug cause?

  • Is the drug habit forming?

  • Do the benefits of over-the-counter status outweigh the risks?

Other questions help determine the ease with which a disease can be diagnosed and then treated outside of a health care setting:

  • Can the average person self-diagnose the condition that calls for the drug?

  • Can the average person treat the condition without the help of a doctor or other health care practitioner?

Finally, people need to understand how to use the drug, so labeling on the outside and inside of the package are important considerations:

  • Can adequate directions for use be written?

  • Can warnings against unsafe use be written?

  • Can the average person understand the information on the label?

Choosing and using over-the-counter drugs

Safety depends on using a drug properly. For OTC drugs, proper use often relies on consumer self-diagnosis, which leaves room for error. For example, most headaches are not dangerous, but in rare cases, a headache is an early warning of a brain tumor or hemorrhage. Similarly, what seems like severe heartburn may signal an impending heart attack. Ultimately, people must use common sense in determining when a symptom or ailment is minor and when it requires medical attention and consult a doctor or pharmacist if they are unsure.

The guidelines for choosing and using OTC drugs are as follows:

  • Make sure that the self-diagnosis is as accurate as possible. Do not assume the problem is “something that is going around.”

  • Choose a product because the ingredients are appropriate for the condition, not because the product has a familiar brand name.

  • Choose a product with the fewest appropriate ingredients. Products that attempt to relieve every possible symptom are likely to expose people to unnecessary drugs, pose additional risks, and cost more.

  • Read the label carefully to determine the correct dose and precautions, including what conditions would make the drug a poor choice.

  • When in doubt, ask a pharmacist or doctor what the most appropriate ingredient or product is.

  • Ask a pharmacist to check for potential interactions with other drugs being used.

  • Ask a pharmacist to identify possible side effects.

  • Do not take more than the recommended dose.

  • Do not take an over-the-counter drug longer than the maximum time suggested on the label. Stop taking the drug if symptoms worsen.

  • Keep all drugs, including over-the-counter drugs, out of the reach of children.

Reading the labels of over-the-counter drugs

People who purchase OTC drugs should read and follow the instructions carefully. Because different formulations—such as immediate-release and controlled-release (slow-release) formulations—may have the same brand name, the label should be checked each time a product is purchased, and the dosage should be noted. Assuming that the dosage is the same is not safe. Also, different formulations with the same brand name may have different ingredients, so checking the ingredients on the label is important. For example, there are several dozen different Tylenol® formulations with a vast array of ingredients and doses. Some Maalox® products contain aluminum and magnesium hydroxide, while others contain calcium carbonate. When selecting a product, people should read the label carefully to determine which product is most appropriate for their particular problem. Labels on OTC drugs, which are required by the FDA, can help people understand a drug's benefits and risks as well as how to use the drug correctly. People should ask a pharmacist if they have any questions about an OTC product.

Often, the labels of OTC drugs do not list the full range of possible side effects. As a result, many people assume that these drugs have few, if any, side effects. For example, the package insert for one analgesic cautions people not to take the drug for more than 10 days for pain. However, the possible serious side effects that can occur with long-term use (such as life-threatening bleeding from the digestive tract) are not mentioned—not on the box, bottle, or package insert. Consequently, people with chronic pain or inflammation may take the drug for a long time without realizing that such use could lead to serious problems.

Reading a Drug Label

Nonprescription drugs in the United States are required to have labels that explain what a drug’s benefits and risks are and how to use the drug correctly. The label is entitled “Drug Facts.” Active ingredients are listed at the top, followed by uses, warnings, directions, other information, and inactive ingredients.

Active ingredient: The drug itself is the active ingredient. Combination products have more than one active ingredient. The drug’s generic name is listed with the amount of drug in each tablet, capsule, or dose unit. The same generic drug may be sold under several different trade (brand) names.

Uses: Symptoms or disorders for which the drug product is recommended are listed.

Warnings: When the drug should not be used, when a doctor or pharmacist should be consulted (and after how long), and which factors can alter the expected response to the drug are listed, usually in four sections.

  • “Ask a doctor before use if you have” lists conditions that can make taking the drug more problematic or unsafe. This section refers to drug-disease interactions.

  • “Ask a doctor or a pharmacist before use if you are taking” lists other drugs that can interfere with the drug’s effectiveness or safety. This section refers to drug-drug interactions.

  • “When using this product” includes common side effects, foods that may interfere with the drug’s effectiveness or safety (drug-food interactions), and special precautions to take (for example, not driving while taking the drug).

  • The last section lists special warnings for women who are pregnant or breastfeeding and for children, with instructions about what to do in case of an overdose.

Directions: How much of the drug and how often to take the drug are given for different age groups, because size and age, among other factors, affect how a person responds to a drug.

Other information: Special instructions, such as how to store the drug so that it does not deteriorate, are listed.

Inactive ingredients: In addition to the drug, drug products—the tablets, capsules, or other formulations that consumers buy—contain substances added to facilitate the administration of the drug, such as ingredients that provide bulk or a pleasant taste and color. Products with the same active ingredient may contain different inactive ingredients. Inactive ingredients are usually harmless, but some of them cause an allergic reaction in a few people, who should look for products made without those ingredients.

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NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
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