August 31, 2005

The FDA is seeking public comment on how it determines when a drug may be marketed as both a prescription and an OTC product -- an inquiry that was prompted by the agency's inability last week to rule on Barr Pharmaceuticals' application for the Plan B emergency contraceptive.

In an advanced notice of proposed rulemaking, published in the Sept. 1 Federal Register, the FDA states that questions have arisen over the years about whether there are any conditions under which an active ingredient may simultaneously be marketed as both a prescription drug product and an OTC drug product.

But the FDA also notes it has already approved a small number of drugs in both Rx and OTC form. The agency's interpretation of section 503(b) of the Federal Food, Drug, and Cosmetic Act, which defines a prescription drug, allows the marketing of the same active ingredient in products that are both prescription and OTC, assuming meaningful differences exist between the two that makes the prescription product safe only under the supervision of a licensed practitioner, the FDA said.

Examples of such drugs include: meclizine, which is an Rx product marketed by Pfizer as Antivert to treat vertigo, and in various OTC products to treat nausea with motion sickness; nicotine products, which are Rx for administration through inhalers and nasal sprays, and OTC in gums, lozenges and patches; and H2 blockers, which are Rx at 300 mg for ulcers, and OTC at 200 mg for heartburn.

"The key distinction in these examples is that there is some meaningful difference between the two products (e.g., indication, strength, route of administration, dosage form) that makes the prescription product safe only under the supervision of a licensed practitioner," the FDA's notice states. "To date, [the] FDA has not allowed marketing of the same active ingredient in a prescription product for one population and in an OTC product for a subpopulation."

This is precisely the scenario Barr proposed in its application for Plan B (synthetic progestin levonorgestrel) -- the drug would be sold OTC to women 16 years and older while remaining Rx for those 15 years and younger. In a widely watched decision Aug. 26, the FDA delayed its decision on Plan B, citing "unprecedented" regulatory questions, including whether age can be used as a criterion for deciding whether a drug may be sold as either an Rx or OTC product.

Instead of making a definitive ruling on Plan B, as many observers had expected, the FDA is seeking public comment on whether to initiate proposed rulemaking to codify its interpretation of section 503(b) regarding when an active ingredient may be simultaneously marketed in both an Rx and OTC product.

To view the notice, go to http://www.fda.gov/OHRMS/DOCKETS/98fr/05n-0345-nap0001.pdf (http://www.fda.gov/OHRMS/DOCKETS/98fr/05n-0345-nap0001.pdf).