Maker of Birth Control Implant Urges Caution

The maker of Norplant birth control implants is urging some women to use backup methods of contraception because of worries about the effectiveness of implants shipped since October.

In a letter dated Aug. 10, Wyeth-Ayerst Laboratories Vice President Dr. Philip J. de Vane also instructed doctors to stop inserting implants that were shipped since October and have expiration dates of 2004.

Routine tests found that the products were “at the lower end for acceptability” for shelf-life stability, Wyeth-Ayerst spokesman Doug Petkus said. “This raised questions in our mind, so we’re taking a very conservative approach.”

Petkus said that the implants met Food and Drug Administration requirements for shelf-life stability, but that Wyeth-Ayerst wanted to ensure that the products would remain effective through their entire shelf life.

Norplant shipped before Oct. 7 should be effective, de Vane said.

About 1 million American women and 5 million women worldwide have used Norplant, which consists of six capsules that are inserted under the skin in the arm. They release a synthetic hormone into the bloodstream to prevent pregnancy for up to five years.

Wyeth-Ayerst said it is unclear how many women might have the implants that have been called into question.

The letter recommends that doctors advise patients to use other, non-hormonal forms of birth control, such as condoms or diaphragms, for “patients in whom the avoidance of pregnancy is of great importance.”

“We don’t believe there’s an incremental risk of pregnancy with these lots, but we want to be sure,” Petkus said.

The company, based in the Philadelphia suburb of St. Davids, said it is trying to determine what caused the low test results.

Planned Parenthood estimates that annually 9,000 of the more than 1.8 million women arranging contraception through their affiliate offices choose Norplant. By comparison, more than half use oral contraceptives.

Last year, Wyeth-Ayerst agreed to pay a reported $54 million to more than 36,000 women to settle claims that the implants caused headaches, irregular menstrual bleeding, nausea and depression. The company admitted no wrongdoing.