Ballay Pharmaceuticals Inc. had a choice nine years ago: seek U.S. approval to sell a prescription decongestant or slip the drug on the market and hope regulators wouldn’t order it off.

Almost 2 percent of U.S. prescriptions dispensed last year, or as many as 73 million, were for unapproved medicines such as Balamine, the FDA estimates. After years of paying little attention, the FDA now says it will step up efforts to get many of the drugs approved or taken off the market

Physicians prescribe unapproved drugs and pharmacies sell them often without knowing their status. Insurance plans, including some tied to the U.S. Medicare program for the disabled and elderly, often pay for unapproved medicines — sometimes knowingly. It is legal to prescribe, fill prescriptions for, and insure unapproved drugs.