Abstract
Background
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.
Results
Obese women had a lower area under the curve (AUC; 1077.2 vs. 1413.7 pg
h/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.
Conclusion
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.
Keywords
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to ContraceptionAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- Oral contraceptive effectiveness according to body mass index, weight, age, and other factors.Am J Obstet Gynecol. 2009; 201: e1-e9
- Obesity and oral contraceptive pill failure.Contraception. 2009; 79: 334-338
- Impact of body weight on observed pregnancy rates with a low-dose estrogen, 91-day extended regimen oral contraceptive.Contraception. 2009; 80: 196
- Effects of obesity on pharmacokinetics implications for drug therapy.Clin Pharmacokinet. 2000; 39: 215-231
- Drug pharmacokinetics in the obese.Fund Clin Pharmacol. 1988; 2: 239-256
- Pharmacokinetics of Implanon: an integrated analysis.Contraception. 1998; 58: 85S-90S
- 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
- Levonorgestrel concentrations during 7 years of continuous use of Jadelle contraceptive implants.Contraception. 2001; 64: 43-49
- Impact of obesity on oral contraceptive pharmacokinetics and hypothalamic–pituitary–ovarian activity.Contraception. 2009; 80: 119-127
- Medical eligibility criteria for contraceptive use.in: 3rd ed. World Health Organization, Geneva2004
- 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
- Radioimmunoassay of serum d-norgestrel in women following oral and intravaginal administration.Contraception. 1975; 12: 279-298
- Oral contraceptives and individual variability of circulating levels of ethinyl estradiol and progestins.Contraception. 2008; 78: 4-9
- Ovarian suppression during oral contraceptive use in normal-weight and obese women.Contraception. 2009; 80: 210
Article info
Publication history
Published online: February 22, 2010
Accepted:
January 14,
2010
Received in revised form:
January 7,
2010
Received:
December 7,
2009
Identification
Copyright
© 2010 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
ScienceDirect
Access this article on ScienceDirectLinked Article
- BMI, pharmacokinetics, and OCP failureContraceptionVol. 82Issue 6
- PreviewDue 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.
- Full-Text
- Preview
- Pharmacokinetics of a combined oral contraceptive in obese and three normal-weight womenContraceptionVol. 82Issue 6
