Levonorgestrel concentrations during 7 years of continuous use of Jadelle contraceptive implants☆
Irving SivinLivia WanSirpa RantaFrancisco AlvarezVivian BracheDaniel R. MishellPhilip D. DarneyArijit BiswasSoledad Dı́azOrawan KiriwatManee Piya AnantCynthia KlaisleMargarita PavezJanet Schechter
79
Citation
6
Reference
10
Related Paper
Citation Trend
Keywords:
Levonorgestrel
Objective To explore the effect of compound levonorgestrel for emergency contraception. Methods Use the open controlled trial,100 cases were divided into the observation group and the control group.The control group received compound levonorgestrel tablets;the observation group received levonorgestrel tablets. Results The total effective rate of the observation group was equal with the control group,the difference was not statistically significant(P 0.05). Conclusion The compound levonorgestrel tablet is useful for emergency contraception.
Levonorgestrel
Emergency Contraception
Cite
Citations (0)
INTRODUCTION: LNG20, a new levonorgestrel intrauterine system, is currently being investigated in a phase 3 study for contraception. The objective was to evaluate levonorgestrel ex vivo release rate over 3 years of LNG20 use. METHODS: Levonorgestrel release rate was estimated by comparing the average initial levonorgestrel content and the residual levonorgestrel content of expelled or removed systems. The initial levonorgestrel content analysis was performed on 10 random samples at lot release. The estimated release rate was determined by residual drug content analysis of 74 samples that were removed or expelled during the phase 3 study. Residual drug content analysis was performed on six or more samples in each 90-day interval through 2.5 years and six samples between 2.5 and 3 years. A first-order exponential model was used to determine the average rate of change of levonorgestrel content over time. The best-fit curve for the change in levonorgestrel content over time was used to estimate the release rate at 0, 1, 2, and 3 years. RESULTS: The average initial levonorgestrel content was 52.0±1.8 mg with an initial release rate of 18.6 micrograms per day. The estimated average release rate at 1, 2, and 3 years of use was 16.3, 14.3, and 12.6 micrograms per day, respectively. The average cumulative release was 6.4, 12.0, and 16.9 mg (12%, 23%, and 33% of the initial loading), respectively. CONCLUSION: LNG20 releases levonorgestrel at a rate that is comparable with known intrauterine systems containing 52 mg levonorgestrel.
Levonorgestrel
Cite
Citations (0)
In a three-year randomized trial that included 398 women, blood samples were collected for the purpose of assaying levonorgestrel concentrations in women using a new two-rod contraceptive implant system or an earlier implant formulation, Norplant®-2 implants. Sample collection was at 1, 3, 6, 9, and 12 months after placement and semiannually thereafter through three years. Resulting assays and analyses showed that levonorgestrel concentrations of each implant formulation decreased significantly with time after placement, with increasing body weight, and with ponderal index. In the third year, several measures indicated that concentrations of the contraceptive drug were higher in women using the LNG ROD implants than in users of the original formulation. No pregnancies occurred among women in either group in the three years. This study provides evidence that the minimum levonorgestrel concentration needed to protect against pregnancy is below 200 pg/ml, and possibly is below 175 pg/ml.
Levonorgestrel
Contraceptive implant
Cite
Citations (65)
Levonorgestrel
Ethinylestradiol
Cite
Citations (28)
Levonorgestrel
Cite
Citations (0)
SUMMARY Thirteen women who were scheduled for hysterectomy volunteered for the study. Nine women had a levonorgestrel‐releasing intrauterine contraceptive device inserted between 36 and 49 days prior to surgery and four women were on oral levonorgestrel treatment for 7 days prior to surgery. After the surgical removal of the uterus, samples of endometrial, myometrial, fallopian tube and fat tissue were obtained. Methods for measuring tissue concentrations of levonorgestrel were developed and the uptake of levonorgestrel by fat tissue in vitro was studied. The concentrations of levonorgestrel in myometrial, fallopian tube and fat tissue were all of the same order, of between 1 and 5 ng/g of wet weight of tissue, in both the intrauterine device group and the orally treated group. In the endometrium the levonorgestrel concentrations were many‐fold higher in the intrauterine device group. The in vitro experiments showed a rapid uptake of levonorgestrel and an unsaturability of the fat tissue by the steroid at the concentrations used. The fat tissue concentrations of levonorgestrel correlated with the plasma concentrations.
Levonorgestrel
Intrauterine device
Cite
Citations (211)
Levonorgestrel
Ethinylestradiol
Cite
Citations (26)
Levonorgestrel
Intrauterine device
Plasma levels
Cite
Citations (0)
(1) The cornerstone of the clinical file on single-agent levonorgestrel (750 mug per tablet) in emergency contraception is a randomised comparative double-blind trial involving nearly 2,000 women. (2) In this trial the efficacy of two levonorgestrel doses (750 mug per dose) was significantly superior to that of two doses of the ethinyloestradiol (100 mug) + levonorgestrel (500 mug) combination: respectively 1.1% and 3.2% of women became pregnant. (3) Nausea and vomiting, dizzy spells and fatigue were half as frequent in the women using single-agent levonorgestrel (750 mug) as in those receiving the combined product. In both groups nearly a third of the women had abnormal periods after treatment.
Levonorgestrel
Emergency Contraception
Cite
Citations (0)
Levonorgestrel
Intrauterine device
Cite
Citations (83)