Wyeth-Ayerst warns doctors of possible problems with Norplant implants

From staff and wire reports

PHILADELPHIA (CNN) -- Wyeth-Ayerst Laboratories has advised physicians that patients should not use lots of Norplant birth control implants made since October 1999 because of questions about their effectiveness.

In routine quality-control testing, the manufacturer found lots of the contraceptive sent out after October 7, 1999 tested on the lower end of the "acceptable range."

While the company said the contraceptive is still effective, officials are urging women -- particularly those who would be medically at risk from a pregnancy -- to use a backup method of contraception until additional tests are done.

Doctors are being advised to use other lots of Norplant.

"We recommend taking this precaution while we further evaluate the shelf life stability of these lots of Norplant and any potential clinical relevance of these findings," a letter from the company said. It was sent to doctors and Norplant wholesalers last week.

The company is working with the U. S. Food and Drug Administration to determine if these particular implants will have any impact on the women who have them. The testing will take about two months.

The Planned Parenthood Federation of America received the company's letter Wednesday.

"While we don't want to be alarmists, we do want to make sure patients have all of the information they need to make decisions which guard their health," said Bonnie McEwin, the organization's vice president of communications.

Women with the implants should talk to their doctor, but there's no need to remove the implants at this time, a Wyeth-Ayerst spokesman said.

Norplant consists of six capsules that are inserted into the upper arm. The implants release a synthetic hormone into the bloodstream to prevent pregnancy. The implants are intended to be effective for up to five years.

According to Planned Parenthood, Norplant starts working within 24 hours of insertion and is one of the most effective forms of birth control. Side effects include irregular menstrual periods, headaches, weight changes and dizziness.

About 1 million American women and 5 million women worldwide are believe to have used Norplant.

The Associated Press contributed to this report.

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Norplant Information from Planned Parenthood
Wyeth-Ayerst

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