Intracervical release of levonorgestrel for contraception

Area of Science:

• Reproductive Medicine
• Pharmacology
• Contraception

Background:

• Intracervical contraceptive devices offer a localized drug delivery system.
• Levonorgestrel is a progestin commonly used in hormonal contraceptives.

Purpose of the Study:

• To evaluate the clinical performance and bleeding patterns of a novel levonorgestrel-releasing intracervical contraceptive device.
• To assess plasma concentrations of levonorgestrel and hormones during the initial 90 days of use.

Main Methods:

• Twenty-one women used the levonorgestrel-releasing intracervical device (20 microgram/day).
• Bleeding patterns, clinical performance, and plasma hormone levels (levonorgestrel, estradiol, progesterone) were monitored.
• Radioimmunoassay was used to measure plasma hormone concentrations.

Main Results:

• Levonorgestrel was rapidly absorbed, reaching detectable plasma levels within 30 minutes.
• Plasma levonorgestrel concentrations varied between subjects but were stable within individuals over time.
• Out of 24 monitored cycles, 19 were ovulatory; frequent intermenstrual bleeding occurred in the first 30 days.
• Two devices were expelled spontaneously; no pregnancies were reported during the study period.

Conclusions:

• The levonorgestrel-releasing intracervical device demonstrates stable pharmacokinetics and effective contraception.
• Further investigation is warranted to address intermenstrual bleeding and expulsion rates, particularly in nulligravid women.