MONDAY, Feb. 27 (HealthDay News) -- A second company has issued a voluntary recall of birth control pills because of a packaging error that could lead to incorrect dosing and expose women to unintended pregnancies.

Glenmark Generics Inc. said the seven lots of birth control pill packets, sold as Norgestimate and Ethinyl Estradiol, do not pose any immediate health risks, but that women using these oral contraceptives should immediately switch to another form of birth control. The company added that it has informed the U.S. Food and Drug Administration of the recall.

"The safety of patients who take our medicines is our first priority. The cause was identified and corrected immediately," the company said in a statement. "At this time, there remains sufficient supply of unaffected lots of material in the marketplace to support demand."

Glenmark did not specify how many pills were affected by the recall. The lot numbers on the packets are: 04110101, 04110106, 04110107, 04110114, 04110124, 04110129 and 04110134.

Doctors offered this advice to women who may be affected by the recall.

"With birth control pills, if the exact count or sequence is out of order the efficacy of the birth control pill could be significantly decreased. If this is the case, patients may be experiencing irregular bleeding and may be at higher risk for unintended pregnancy," said Dr. Adam Jacobs, an assistant professor of obstetrics, gynecology and reproductive science at Mount Sinai Medical Center in New York City.

"This packaging error does not pose any other immediate health risks. If a patient has this lot number they should stop taking the pills immediately and discuss other birth control options with their physician, including emergency contraception, if necessary," Jacobs added.

"Sequence and content of active vs. inactive pills is crucial in determining efficacy, including whether or not unwanted pregnancy will be actually prevented," said Dr. Jill Rabin, chief of ambulatory care, obstetrics and gynecology at Long Island Jewish Medical Center in New Hyde Park, N.Y. "Expiration date could also affect efficacy of the pill in question, as active ingredient potency may be affected. Fortunately, the exact cause of this packaging error was identified and immediately reported."

However, patients who are affected by this should do several important things, Rabin added. Make sure you are not pregnant; immediately begin using a non-hormonal form of contraception if not pregnant; notify your physician/health care provider; and return the product to your pharmacy.

The pills involved in the latest recall were sent to wholesalers and retail pharmacies nationwide between Sept. 21, 2011 and Dec. 30, 2011. Glenmark said it discovered the packaging problem after a customer complained that one of her blister packs had the pills packaged in reverse order.

Earlier this month, Pfizer Inc. recalled 1 million packets of birth control pills for similar reasons. At the time, the company said it had discovered that some blister packs of Lo/Ovral and generic Norgestrel and Ethinyl Estradiol had packaging that could contain either too many or too few active pills and that the pills may be out of sequence. The expiration dates on those recalled packets range between July 31, 2013 and March 31, 2014.

More information

Here's where you can find more details on the Glenmark recall.