Protease Inhibitors and Combined Oral Contraceptive Pharmacokinetics and Pharmacodynamics
Status:
Terminated
Trial end date:
2016-11-01
Target enrollment:
Participant gender:
Summary
The project is a two-arm prospective cohort and pharmacokinetic study comparing
levonorgestrel and ethinyl estradiol pharmacokinetics in HIV-positive women taking
antiretroviral regimens that include ritonavir to those in women who take regimens known not
to interact with combined oral contraceptives. In addition, the prevalence of ovulation will
be measured in each group. Participants will take a combined oral contraceptive containing
levonorgestrel and ethinyl estradiol for 21 days, during which they will undergo twice-weekly
serum progesterones. On the final day, they will complete a pharmacokinetic study. The
investigators hypothesize that levonorgestrel levels, as measured by area-under-the-curve
from 0 to 72 hours, will be increased in women on ritonavir, while ethinyl estradiol levels
will be decreased and ovulation, defined by a serum progesterone of at least 3 ng/mL, will be
unchanged.
This study will be the first to evaluate the effects of ritonavir on the pharmacokinetics of
a combined oral contraceptive containing the progestin levonorgestrel. In addition, no
previous studies have rigorously assessed ovulation in women taking protease inhibitors and
combined oral contraceptives. As a result, this study will provide new information
correlating pharmacokinetic changes with effects on ovulation.