Was the FDA Aware of Migration Risk Prior to Implanon Approval?

December 29, 2016, 8:30AM. By Gordon Gibb

Washington, DCAnyone doing an online search for 'Implanon' will immediately be led to a site index where consumers will find links to both patient information intended for consumers, and prescribing information intended for doctors. And while there appears to be no indication as to if, and when the latter may have been updated, the patient document intended for consumers is identified as having been updated with regard to Implanon usage and Implanon birth control side effects in March of this year.

That’s also when the US Food and Drug Administration (FDA) requested updated warning labels to highlight the potential for device migration.

To give credit where credit is due, Implanon manufacturer Merck & Co. and its subsidiary Organon, provide good information with regard to the risks associated with Implanon – and the rare potential for device migration – for consumers who take the time to read the information. And while device migration remains a rare Implanon birth control side effect, device migration was foreshadowed before Implanon arrived on the market.

Implanon (and its successor Nexplanon) are implantable birth control devices inserted just under the skin in the inside upper arm for dispensation of non-estrogen birth control for a three-year period. Implanon birth control will last longer than three years, but the latter time frame is the recommended interval at which to remove the nearly-spent Implanon for replacement – or to switch to an alternative birth control device, at the patient’s option.

There are various Implanon birth control side effects, the most common of which are listed for consumers on the Merck & Co. official site for Implanon. Towards the bottom of Page 7, appearing almost as an aside is this: “Implants have been reported to be found in a blood vessel including a blood vessel in the lung.”

Without specifically referencing device migration, it is nonetheless inferred given the distance between the inside of the upper arm and the lung.

Device migration is addressed a second time further down in the document. From Page 8, beginning with the second paragraph under a sub-head ‘Problems with Insertion and Removal’:

“Location and removal of the implant may be difficult or impossible because the implant is not where it should be. Special procedures, including surgery in the hospital, may be needed to remove the implant. If the implant is not removed, then the effects of IMPLANON (sic) will continue for a longer period of time.

“Implants have been found in the pulmonary artery (a blood vessel in the lung). If the implant cannot be found in the arm, your healthcare professional may use imaging methods on the chest. If the implant is located in the chest, surgery may be needed.”

While device migration continues to be rare, the problems were foretold through the history of a previous product that was on the market long before Implanon was approved by the FDA in 2006.

Norplant, manufactured by Wyeth Pharmaceuticals, was a series of six small capsules, or rods implanted in similar fashion to the single-application Implanon. Extraction was an even greater issue given that six devices needed to be located and removed, rather than one.

What’s more, an article
released in 1995 suggested that in rare cases, one or more of the Norplant capsules could not easily be located, suggesting device migration. Norplant was removed from the market altogether in 2000, six years before the approval or Implanon.

The successor to Implanon, called Nexplanon, mirrors Implanon with one telling exception: the addition of barium sulfate, which makes it easier to trace a rod having migrated away from the original insertion site.

In spite of all Nexplanon rods equipped with barium sulfate, device migration is still considered a rare side effect.

Lawsuits alleging Implanon birth control consumer fraud claim patients were not fully aware of the potential for device migration, or the difficulty oft encountered when attempting to remove the device.