Pharmacokinetics of the etonogestrel contraceptive implant in obese women
Mornar, S.; Chan, L.-N.; Mistretta, S.; Neustadt, A.; Martins, S.; Gilliam, M.
American Journal of Obstetrics and Gynecology 207(2): 110.E1-6
2012
ISSN/ISBN: 1097-6868 PMID: 22717269 DOI: 10.1016/j.ajog.2012.05.002Document Number: 552567
We sought to examine the pharmacokinetics and acceptability of the etonogestrel contraceptive implant in obese women. We developed and validated a plasma etonogestrel concentration assay and enrolled 13 obese (body mass index ≥30) women and 4 normal-weight (body mass index <25) women, who ensured comparability with historical controls. Etonogestrel concentrations were measured at 50-hour intervals through 300 hours postinsertion, then at 3 and 6 months to establish a pharmacokinetic curve. All obese participants were African American, while all normal-weight participants were white. Across time, the plasma etonogestrel concentrations in obese women were lower than published values for normal-weight women and 31-63% lower than in the normal-weight study cohort, although these differences were not statistically significant. The implant device was found highly acceptable among obese women. Obese women have lower plasma etonogestrel concentration than normal-weight women in the first 6 months after implant insertion. These findings should not be interpreted as decreased contraceptive effectiveness without additional considerations.
Document emailed within 0-6 h
