Rx to OTC: The Switch Is On

by Food and Drug Administration (FDA)

What do Dimetapp, Sominex, Bactine, Cortaid, Coricidin Nasal Mist, OcuClear, E-Z Scrub 241, Trosyd, and Actifed have in common? They, along with dozens of other drug products, have made the "switch" from prescription to over-the-counter (OTC) status.

The Nonprescription Drug Manufacturers Association estimates that more than 200 OTC drug products on the market today were available by prescription only a decade ago. Among them are antihistamines and nasal decongestants for colds and allergies, sleep aids, pain relievers, cough medicines, antifungals, antimicrobials, and anti-itch medicines. These products contain ingredients in dose strengths that the Food and Drug Administration has deemed safe enough to use without a doctor's prescription.

When this issue of FDA Consumer went to press, the most recent ingredient that FDA had approved for the switch from prescription to OTC sale was clotrimazole in cream and suppository dosage forms. Used to treat vaginal yeast infections, clotrimazole has been available by prescription for more than 10 years. It will be marketed OTC under the trade name Gyne-Lotrimin. In announcing the switch, Carl Peck, M.D., director of FDA's Center for Drug Evaluation and Research, said, "Clotrimazole is highly effective and carries a minimal risk. If initially diagnosed by a doctor, recurring symptoms of vaginal yeast infection, or candidiasis, can be recognized by the patient, who can treat herself with the over-the-counter drug without the inconvenience and expense of going back to the doctor."

Some other prescription products the drug industry is interested in switching, according to the July 9, 1990, Advertising Age, are the antacids Zantac, Carafate, Tagamet, and Pepcid; the cold/allergy medications Claritin, Hismanal and Seldane; and the nonsteroidal anti-inflammatory drugs Naprosyn, Clinoril, Feldene, and Anaprox. The publication also reported a projection that the OTC drug market would reach $19 billion in manufacturer sales by the year 2000, up 72% from $11 billion in 1990.

OTC Drug Review

A major impetus for switching drugs from prescription to OTC status is FDA's comprehensive review, begun in 1972, of the active ingredients in OTC drug products. The review grew out of amendments to drug law enacted in 1962, which require drugs to be proven effective before they can be marketed. (Before Congress passed this legislation, drugs had to be proven safe, but proof of their effectiveness was not required by law.)

Thus, FDA was obliged to reexamine all drugs — both prescription and OTC — that had been approved solely on the basis of safety. For OTC drugs, the endeavor involved about 730 active ingredients that were used in more than 300,000 drug products sold in the United States. The review separated the active ingredients in the products into therapeutic classes — for example, anti-itch medicines, antihistamines and antifungals. Seventeen panels of nongovernment experts were established to make recommendations about the safety and effectiveness of ingredients for their intended uses. As a result of the review, some ingredients were taken off the market because they were found ineffective; others were banned for safety reasons.

In addition to evaluating safety and efficacy of OTC drugs, the panels reviewed currently marketed prescription ingredients to determine whether some might be appropriate for OTC marketing. Some panels determined that dosages of certain OTC ingredients, such as antihistamines, needed to be raised to levels that were previously allowed by prescription only. So far, nearly 40 formerly prescription-only drug ingredients in at least 16 classes have been switched to OTC status.

What Determines Rx vs. OTC

The distinction between prescription and nonprescription drugs is spelled out in the Durham-Humphrey Amendment to the Federal Food, Drug, and Cosmetic Act. Before this amendment was passed in 1951, there was no specific statutory requirement that any drug be labeled for sale by prescription only. With the amendment, prescription drugs were defined primarily as those unsafe for use except under professional supervision. They include certain habit-forming drugs and any drug that is unsafe "because of its toxicity or other potentiality for harmful effect, or the method of its use, or the collateral measures necessary to its use ... ."

Nonprescription drugs are regarded as safe for consumers to use by following the directions and warnings required on the label.

To protect consumers, FDA regulations require that labeling of OTC drugs state:

• the intended uses and results of the product
• adequate directions for proper use
• warnings against unsafe use, side effects, and adverse reactions.

The labeling must be written so that ordinary people, including those with somewhat low reading comprehension skills, would be likely to understand it.

Toxicity is the major issue in deciding whether to switch a drug from prescription to OTC status. Because almost any drug, if misused, can have some adverse side effect, one way to evaluate possible harm in switching is to consider the drug's overall margin of safety.

Gerald Rachanow, J.D., deputy director of FDA's division of OTC drug evaluation, explains that, "Drugs that have a high risk of causing toxicity and a low margin of safety, and that must be carefully used to achieve the appropriate level of effectiveness without endangering the consumer's safety, are appropriately classified as prescription drugs."

On the other hand, Rachanow says, "the mere possibility that a drug can be misused, with toxic results, is not a sufficient basis alone to classify it for prescription status."

OTC Labels

The process of switching some antihistamines to OTC status can serve as an example of the procedure. Antihistamines are used to relieve symptoms of hay fever and other upper respiratory allergies. They may cause drowsiness, however, presenting a hazard if taken in circumstances where alertness is important. Antihistamines also can be dangerous to patients with glaucoma, an enlarged prostate, or asthma.

In reviewing antihistamines, FDA's Cough/Cold Advisory Review Panel did not find these potential dangers sufficient cause to limit these ingredients to prescription use. It recommended instead that the labeling for OTC antihistamine drug products bear a warning that the product "may cause drowsiness" and caution consumers to "avoid driving a motor vehicle or operating heavy machinery" and to "avoid alcoholic beverages while taking this product." The panel also recommended that the label warn patients not to take these products except with the advice and supervision of a physician if they have glaucoma, asthma, or difficulty urinating because of an enlarged prostate.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.