Original research article| Volume 81, ISSUE 6, P474-480, June 2010

Pharmacokinetics of a combined oral contraceptive in obese and normal-weight women



      This study was conducted to compare oral contraceptive (OC) pharmacokinetics (PK) in normal-weight [body mass index (BMI) 19.0–24.9] and obese (BMI 30.0–39.9) women.

      Study Design

      During the third week of the third cycle of OC use, we admitted 15 normal-weight and 15 obese women for collection of 12 venous specimens over 24 h. Using radioimmunoassay techniques, we measured levels of ethinyl estradiol (EE) and levonorgestrel (LNG). During the same cycle, women underwent twice-weekly sonography to assess ovarian follicular development and blood draws to measure endogenous estradiol (E2) and progesterone levels.


      Obese women had a lower area under the curve (AUC; 1077.2 vs. 1413.7 pglow asteriskh/mL) and lower maximum values (85.7 vs. 129.5 pg/mL) for EE than normal-weight women (p=.04 and <0.01, respectively); EE trough levels were similar between BMI groups. The similar, but smaller, differences in their LNG levels for AUC and maximum values (Cmax) were not statistically significant. While peak values differed somewhat, the LNG trough levels were similar for obese and normal-weight women (2.6 and 2.5 ng/mL, respectively). Women with greater EE AUC had smaller follicular diameters (p=.05) and lower E2 levels (p=.04). While follicular diameters tended to be larger among obese women, these differences were not statistically significant.


      OC hormone peak levels are lower among obese women compared to normal-weight women, but their trough levels are similar. In this small study, the observed PK differences did not translate into more ovarian follicular activity among obese OC users.


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        • Dinger J.C.
        • Cronin M.
        • Mohner S.
        • Schellschmidt I.
        • Minh T.D.
        • Westhoff C.
        Oral contraceptive effectiveness according to body mass index, weight, age, and other factors.
        Am J Obstet Gynecol. 2009; 201: e1-e9
        • Trussell J.
        • Schwarz E.B.
        • Guthrie K.
        Obesity and oral contraceptive pill failure.
        Contraception. 2009; 79: 334-338
        • Weshtoff C.
        • Reape K.
        • Shu H.
        Impact of body weight on observed pregnancy rates with a low-dose estrogen, 91-day extended regimen oral contraceptive.
        Contraception. 2009; 80: 196
        • Cheymol G.
        Effects of obesity on pharmacokinetics implications for drug therapy.
        Clin Pharmacokinet. 2000; 39: 215-231
        • Cheymol G.
        Drug pharmacokinetics in the obese.
        Fund Clin Pharmacol. 1988; 2: 239-256
        • Huber J.
        Pharmacokinetics of Implanon: an integrated analysis.
        Contraception. 1998; 58: 85S-90S
        • Rahimy M.H.
        • Cromie M.A.
        • Hopkins N.K.
        • Tong D.M.
        Lunelle(TM) monthly contraceptive injection (medroxyprogesterone acetate and estradiol cypionate injectable suspension): effects of body weight and injection sites on pharmacokinetics.
        Contraception. 1999; 60: 201-208
        • Sivin I.
        • Wan L.
        • Ranta S.
        • et al.
        Levonorgestrel concentrations during 7 years of continuous use of Jadelle contraceptive implants.
        Contraception. 2001; 64: 43-49
        • Edelman A.B.
        • Carlson N.E.
        • Cherala G.
        • et al.
        Impact of obesity on oral contraceptive pharmacokinetics and hypothalamic–pituitary–ovarian activity.
        Contraception. 2009; 80: 119-127
        • World Health Organization Department of Reproductive Health and Research
        Medical eligibility criteria for contraceptive use.
        in: 3rd ed. World Health Organization, Geneva2004
        • Price T.M.
        • Dupuis R.E.
        • Carr B.R.
        • Stanczyk F.Z.
        • Lobo R.A.
        • Droegemueller W.
        Single- and multiple-dose pharmacokinetics of a low-dose oral contraceptive in women with chronic renal failure undergoing peritoneal dialysis.
        Am J Obstet Gynecol. 1993; 168: 1400-1406
        • Stanczyk F.Z.
        • Hiroi M.
        • Goebelsmann U.
        • Brenner P.F.
        • Lumkin M.E.
        • Mishell Jr, D.R.
        Radioimmunoassay of serum d-norgestrel in women following oral and intravaginal administration.
        Contraception. 1975; 12: 279-298
        • Goldzieher J.W.
        • Stanczyk F.Z.
        Oral contraceptives and individual variability of circulating levels of ethinyl estradiol and progestins.
        Contraception. 2008; 78: 4-9
        • Westhoff C.
        • Torgal A.
        • Mayeda E.R.
        • Lerner J.
        • Paik M.
        Ovarian suppression during oral contraceptive use in normal-weight and obese women.
        Contraception. 2009; 80: 210

      Linked Article

      • BMI, pharmacokinetics, and OCP failure
        ContraceptionVol. 82Issue 6
        • Preview
          Due to the intensity of pharmacokinetic studies, the sample sizes are often small. Thus, we were excited to have the opportunity to compare results from our prior publication with the recent paper by Westhoff et al. [1,2]. Both studies found significant differences in the pharmacokinetic (PK) parameters between obese and normal-body mass index (BMI) women using oral contraceptives (OCP), but the differences varied. This could be due to the use of a low (30 mcg ethinyl estradiol [EE]/150 mcg levonorgestrel [LNG]) versus a very-low (20 mcg EE/100 mcg LNG) OC.
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      • Pharmacokinetics of a combined oral contraceptive in obese and three normal-weight women
        ContraceptionVol. 82Issue 6