First week drug concentrations in women with levonorgestrel rod or Norplant capsule implants

Development and validation of a multiplexed assay for the measurement of long-acting hormonal contraceptives in plasma via liquid chromatography-tandem mass spectrometry

BACKGROUND

Exogenous progestins are an effective tool for hormonal contraception and family planning. Progestins may be delivered as oral pills, intramuscular or subcutaneous injections, vaginal rings, or intrauterine devices. Drug concentrations may vary based on the route and duration of delivery. Measurement of synthetic steroids in blood plasma can aid in determination of product adherence, evaluation of drug-drug interactions, and investigation of unintended pregnancies.

METHODS

Drug-free K2EDTA plasma was spiked with the synthetic steroids etonogestrel (ETO), levonorgestrel (LNG), medroxyprogesterone acetate (MPA), and norethisterone (NET). Plasma was combined with isotopically labeled internal standards, and drugs were extracted via liquid-liquid extraction. Samples were then subjected to liquid chromatographic-tandem mass spectrometric (LC-MS/MS) analysis. The method was validated in accordance with regulatory recommendations. The assay was evaluated in a cohort of remnant plasma samples in individuals using one of the aforementioned progestins.

RESULTS

The analytical measuring range for ETO, MPA, and NET was 20-10,000 pg/mL; the primary linearity for LNG was 20-20,000 pg/mL. The method showed acceptable precision and accuracy for all progestins. Stability was established for 72 h with room temperature storage and through 3 freeze-thaw cycles. All analytes were stable in whole blood incubated at room temperature for 25 h, and at 40°C and 100% humidity for 2 h. Ion suppression was observed for all analytes spiked in plasma; average ion suppression was 31.6%, 66.6%, 32.1% and 41.2% for ETO, LNG, MPA, and NET, respectively. However, internal standards showed comparable ion suppression, and relative matrix effects were minimal. ETO, LNG, MPA, and NET could also be quantified accurately in K3EDTA plasma and serum. Progestins were successfully measured in remnant samples from individuals using hormonal contraceptives.

CONCLUSIONS

A multiplexed LC-MS/MS assay for the quantification of ETO, LNG, MPA, and NET has been developed and validated. The assay met acceptable performance characteristics and may be used in downstream studies to evaluate progestin pharmacology.

Levonorgestrel Microneedle Array Patch for Sustained Release Contraception: Formulation, Optimization and In Vivo Characterization

Background: The goal of this work was to develop a levonorgestrel liposome-loaded microneedle array patch for contraception. Methods: Levonorgestrel-loaded liposome was formulated by a solvent injection technique, characterized, and studied. Results: The formulated liposomes were characterized for particle size (147 ± 8 nm), polydispersity index (0.207 ± 0.03), zeta potential (−23 ± 4.25 mV), drug loading (18 ± 3.22%) and entrapment efficiency (85 ± 4.34%). A cryo high-resolution transmission electron microscopy and cryo field emission gun scanning electron microscopy study showed spherical shaped particles with a smooth surface. The in vitro drug release and in vivo pharmacokinetic study showed sustained behaviour of Levonorgestrel for 28 days. Conclusion: The levonorgestrel liposome-loaded microneedle array patch showed better contraception than the drug-loaded microneedle array patch.

Impact of one-rod levonorgestrel implant on the blood chemistry profile

The aim of this study was to investigate the effect of a one-rod levonorgestrel implant on the blood chemistry profile, including random blood glucose (RBG), haemoglobin (Hb), alanine transferase (ALT), aspartate transferase (AST), and the lipid profile, including total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides. This prospective cohort study was conducted at Raden Saleh Clinic, Jakarta, from 2010 to 2012. The implants were inserted subdermally in 30 patients. The subjects were evaluated every 6 month up to 2 years. Bivariate analysis using t-test or Wilcoxon signed rank test was performed for all variables. p < 0.05 was considered a significant value. The Hb, RBG, AST, and lipid profile levels were significantly different before and 6 months after one-rod implant insertion (p < 0.05). However, for 24 months, all of the parameters were still within normal limits and did not differ clinically. One-rod levonorgestrel implant insertion has a minimal effect on all blood chemistry profiles.

Pharmacokinetics, metabolism and serum concentrations of progestins used in contraception

Many different forms of hormonal contraception are used by millions of women worldwide. These contraceptives differ in the dose and type of synthetic progestogenic compound (progestin) used, as well as the route of administration and whether or not they contain estrogenic compounds. There is an increasing awareness that different forms of contraception and different progestins have different side-effect profiles, in particular their cardiovascular effects, effects on reproductive cancers and susceptibility to infectious diseases. There is a need to develop new methods to suit different needs and with minimal risks, especially in under-resourced areas. This requires a better understanding of the pharmacokinetics, metabolism, serum and tissue concentrations of progestins used in contraception as well as the biological activities of progestins and their metabolites via steroid receptors. Here we review the current knowledge on these topics and identify the research gaps. We show that there is a paucity of research on most of these topics for most progestins. We find that major impediments to clear conclusions on these topics include a lack of standardized methodologies, comparisons between non-parallel clinical studies and variability of data on serum concentrations between and within studies. The latter is most likely due, at least in part, to differences in intrinsic characteristics of participants. The review highlights the importance of insight on these topics in order to provide the best contraceptive options to women with minimal risks.

Development, validation and utilization of a highly sensitive LC-MS/MS method for quantification of levonorgestrel released from a subdermal implant in human plasma

Levonorgestrel (LNG) is a synthetic progestin that is available in oral contraceptive tablets, a subdermal implant, and an intrauterine system for contraception. LNG pharmacokinetics are a pivotal determinant of contraceptive efficacy and essential in assessing drug-drug interactions influencing LNG exposure following different routes of LNG administration. A highly sensitive LC-MS/MS method was developed and validated to quantify levonorgestrel in human plasma. Liquid-liquid extraction was utilized with a sample volume of 500 μL to extract levonorgestrel from plasma. Chromatographic separation of LNG was achieved with a Fortis™ C18 (3 μm: 100 mm × 2.1 mm) reverse phase analytical column. The mobile phases consisted of de-ionized water plus 0.1% NH4OH (100:0.1%, v/v) (A), and methanol plus 0.1% NH4OH (100:0.1%, v/v) (B) delivered as a gradient at a flow rate of 400 μL/min. Detection of LNG and internal standard (D-(-)-norgestrel-d7) was achieved using positive polarity mode monitoring at 313.2-245.2 amu and 320.1-251.2 amu, respectively. The assay was linear over the calibration range of 49.6 to 1500 pg/mL. This method was used to quantify plasma LNG released by subdermal implant in support of a drug interaction study among women with HIV receiving efavirenz- or nevirapine-based antiretroviral therapy.

The Effect of Gene Variants on Levonorgestrel Pharmacokinetics When Combined With Antiretroviral Therapy Containing Efavirenz or Nevirapine

Reduced levonorgestrel concentrations from the levonorgestrel contraceptive implant was previously seen when given concomitantly with efavirenz. We sought to assess whether single nucleotide polymorphisms (SNPs) in genes involved in efavirenz and nevirapine metabolism were linked to these changes in levonorgestrel concentration. SNPs in CYP2B6, CYP2A6, NR1I2, and NR1I3 were analyzed. Associations of participant demographics and genotype with levonorgestrel pharmacokinetics were evaluated in HIV-positive women using the levonorgestrel implant plus efavirenz- or nevirapine-based antiretroviral therapy (ART), in comparison to ART-naïve women using multivariate linear regression. Efavirenz group: CYP2B6 516G>T was associated with lower levonorgestrel log₁₀ C_max and log₁₀ AUC. CYP2B6 15582C>T was associated with lower log₁₀ AUC. Nevirapine group: CYP2B6 516G>T was associated with higher log₁₀ C_max and lower log₁₀ C_min . Pharmacogenetic variations influenced subdermal levonorgestrel pharmacokinetics in HIV-positive women, indicating that the magnitude of the interaction with non-nucleoside reverse transcriptase inhibitors (NNRTIs) is influenced by host genetics.

Unintended Pregnancies Observed With Combined Use of the Levonorgestrel Contraceptive Implant and Efavirenz-based Antiretroviral Therapy: A Three-Arm Pharmacokinetic Evaluation Over 48 Weeks

BACKGROUND

Levonorgestrel subdermal implants are preferred contraceptives with an expected failure rate of <1% over 5 years. We assessed the effect of efavirenz- or nevirapine-based antiretroviral therapy (ART) coadministration on levonorgestrel pharmacokinetics.

METHODS

This nonrandomized, parallel group, pharmacokinetic evaluation was conducted in three groups of human immunodeficiency virus-infected Ugandan women: ART-naive (n = 17), efavirenz-based ART (n = 20), and nevirapine-based ART (n = 20). Levonorgestrel implants were inserted at baseline in all women. Blood was collected at 1, 4, 12, 24, 36, and 48 weeks. The primary endpoint was week 24 levonorgestrel concentrations, compared between the ART-naive group and each ART group by geometric mean ratio (GMR) with 90% confidence interval (CI). Secondary endpoints included week 48 levonorgestrel concentrations and unintended pregnancies.

RESULTS

Week 24 geometric mean levonorgestrel concentrations were 528, 280, and 710 pg/mL in the ART-naive, efavirenz, and nevirapine groups, respectively (efavirenz: ART-naive GMR, 0.53; 90% CI, .50, .55 and nevirapine: ART-naive GMR, 1.35; 90% CI, 1.29, 1.43). Week 48 levonorgestrel concentrations were 580, 247, and 664 pg/mL in the ART-naive, efavirenz, and nevirapine groups, respectively (efavirenz: ART-naive GMR, 0.43; 90% CI, .42, .44 and nevirapine: ART-naive GMR, 1.14; 90% CI, 1.14, 1.16). Three pregnancies (3/20, 15%) occurred in the efavirenz group between weeks 36 and 48. No pregnancies occurred in the ART-naive or nevirapine groups.

CONCLUSIONS

Within 1 year of combined use, levonorgestrel exposure was markedly reduced in participants who received efavirenz-based ART, accompanied by contraceptive failures. In contrast, nevirapine-based ART did not adversely affect levonorgestrel exposure or efficacy.

CLINICAL TRIALS REGISTRATION

NCT01789879.

Sino-implant (II)® continuation and effect of concomitant tenofovir disoproxil fumarate-emtricitabine use on plasma levonorgestrel concentrations among women in Bondo, Kenya

OBJECTIVE

The objective was to assess associations between tenofovir disoproxil fumarate-emtricitabine (TDF-FTC) exposure and levonorgestrel (LNG) concentrations among Kenyan HIV prevention trial participants using Sino-implant (II) LNG implants for contraception.

METHODS

Women were offered implants among other contraceptive methods, were randomized to daily TDF-FTC or placebo, and followed monthly up to 56weeks. Associations between TDF-FTC exposure and mean LNG values were analyzed with linear mixed models.

RESULTS

Of 739 women, 29 (3.9%) received implants with no incident pregnancies and one discontinuation. Mean LNG concentrations over 56weeks among 28 women contributing data ranged between 214.0 and 659.8pg/mL with no significant difference between TDF-FTC and placebo arms or between variable levels of TDF-FTC adherence.

CONCLUSION

Concomitant TDF-FTC use was not associated with a significant change in plasma LNG concentrations among women using Sino-implant (II) in the first year of use.

Mating skew in Barbary macaque males: the role of female mating synchrony, female behavior, and male-male coalitions

A fundamental question of sexual selection theory concerns the causes and consequences of reproductive skew among males. The priority of access (PoA) model (Altmann, Ann NY Acad Sci 102:338-435, 1962) has been the most influential framework in primates living in permanent, mixed-sex groups, but to date it has only been tested with the appropriate data on female synchrony in a handful of species. In this paper, we used mating data from one large semi-free ranging group of Barbary macaques: (1) to provide the first test of the priority-of-access model in this species, using mating data from 11 sexually active females (including six females that were implanted with a hormonal contraceptive but who showed levels of sexual activity comparable to those of naturally cycling females) and (2) to determine the proximate mechanism(s) underlying male mating skew. Our results show that the fit of the observed distribution of matings with sexually attractive females to predictions of the PoA model was poor, with lower-ranking males mating more than expected. While our work confirms that female mating synchrony sets an upper limit to monopolization by high-ranking individuals, other factors are also important. Coalitionary activity was the main tactic used by males to lower mating skew in the study group. Coalitions were expressed in a strongly age-related fashion and allowed subordinate, post-prime males to increase their mating success by targeting more dominant, prime males. Conversely, females, while mating promiscuously with several males during a given mating cycle, were more likely to initiate their consortships with prime males, thus reducing the overall effectiveness of coalitions. We conclude that high-ranking Barbary macaque males have a limited ability to monopolize mating access, leading to a modest mating skew among them.

Levonorgestrel, not etonogestrel, provides contraception in free-ranging koalas

Management of high-density koala (Phascolarctos cinereus) populations is essential because of the browsing damage they inflict on their habitat. We have tested two types of gestagen implant, namely levonorgestrel and etonogestrel, as contraceptives for koalas. Free-ranging female koalas were given either a control, levonorgestrel (70 mg) or etonogestrel (34 or 68 mg) implant before the breeding season. Koalas were monitored every 4–12 weeks for births. Plasma progesterone was measured and a cytological smear of the urogenital sinus was taken. Fertility was high in the control group and the two etonogestrel-treated groups, with approximately 90% of females giving birth. In contrast, no levonorgestrel-treated female produced young during the study. Removal of levonorgestrel implants from six females reversed the contraceptive effect in the next breeding season, whereas the eight females in which the levonorgestrel implants were left in remained infertile for six breeding seasons. Vaginal cytology showed evidence of oestrous cycles during the breeding season in all females from all groups and there was no difference seen in the prevalence of cornified epithelial cells in the oestrous smears. This indirectly suggests that levonorgestrel does not prevent follicular development and oestrous cycling. Plasma progesterone in levonorgestrel-treated females remained low all year, but rose in controls concurrent with the onset of the breeding season. This suggests that levonorgestrel prevents pregnancy by blocking ovulation. Etonogestrel had absolutely no contraceptive effect at the two doses delivered and so is not suitable for controlling koala populations. In contrast, levonorgestrel was effective as a long-term, reversible contraceptive in wild koalas.

The effect of hysterectomy or levonorgestrel-releasing intrauterine system on sexual functioning among women with menorrhagia: a 5-year randomised controlled trial

OBJECTIVE

To compare among women with menorrhagia the effect of hysterectomy or levonorgestrel-releasing intrauterine system (LNG-IUS) on sexual functioning.

DESIGN

A randomised controlled trial.

SETTING

Five university hospitals in Finland.

SAMPLE

A total of 236 women, aged 35-49 years.

METHODS

Of the women, 117 were treated by hysterectomy and 119 by LNG-IUS.

MAIN OUTCOME MEASURES

Sexual functioning was evaluated by modified McCoy sexual scale at baseline and at 6 months, 12 months, and 5 years after initiation of treatment (hysterectomy or application of LNG-IUS).

RESULTS

Among women treated by hysterectomy, sexual satisfaction increased and sexual problems decreased. Among LNG-IUS users, satisfaction with partner decreased. In addition to treatment modality (P = 0.02), estrogen therapy (P = 0.01), smoking (P = 0.001), night sweats (P = 0.03), vaginal dryness (P = 0.04), hot flushes (P = 0.01), and having someone to ask for advice (P = 0.03) and to share worries (P = 0.01) explained changes in sexual functioning.

CONCLUSIONS

Among women with menorrhagia, hysterectomy improves sexual functioning, whereas LNG-IUS does not have such a positive effect.

Randomized controlled trial of the effect of hysterectomy or LNG-IUS use on bone mineral density: a five-year follow-up

A 72-year-old female with scirrhous-type advanced gastric cancer was treated with TS-1/CDDP as neoadjuvant chemotherapy. TS-1 (80 mg/m(2)/day) was orally administered for 3 weeks and CDDP (60 mg/m(2)) was administered by intravenous drip on day 8. Partial response (PR) was obtained after the first course, and total gastrectomy was performed. The histological diagnosis revealed complete disappearance of cancer cells in the stomach and a few regional lymph node metastases (3/67). The patient has now been in good health without a recurrence for 1 year and 9 months after surgery.

Progestin implants for female contraception

Four different implants, in the form of capsules or covered rods, that release one of the synthetic progestins levonorgestrel, etonogestrel, Nestorone, or Elcometrine and nomegestrol acetate were reviewed. Biocompatible polymers or copolymers of polydimethyl/polymethylvinyl-siloxanes or ethylvinylacetate are used to hold the steroid crystals and to control the rate of release. Once inserted under the skin, these implants release the corresponding steroid continuously over prolonged periods, a process that can be readily interrupted by implant removal. During long-term use of the implant, the released steroid circulates in blood at a fairly stable level. The physical characteristics of the implants, including drug contents and rate of release, serum levels of the progestin during use, and the duration of their effective life are described. Total steroid loads vary in the range of 50 mg to 216 mg; average release rates are in the range of 30-100 ug/day, and effective lives from 6 months to 7 years.

In vitro and in vivo evaluations of biodegradable implants for hormone replacement therapy: effect of system design and PK-PD relationship

This investigation evaluated the feasibility of using subdermally implantable devices fabricated by nonconventional 3-dimensional printing technology for controlled delivery of ethinyl estradiol (EE2). In vitro release kinetics of EE2 and in vivo pharmacokinetics/pharmacodynamics in ovariectomized New Zealand White rabbits were carried out to study 3 implant prototypes: implant I (single-channel EE2 distribution in polycaprolactone polymer core), implant II (homogeneous EE2 distribution in polycaprolactone polymer matrix), and implant III (concentration-gradient EE2 distribution in polycaprolactone and poly(dl-lactide-co-glycolide) (50:50 matrix). EE2 was found to be released from all the implants in a nonlinear pattern with an order of implant III > implant II > implant I. The noncompartmental pharmacokinetic analysis of plasma EE2 profiles in rabbits indicated a significant difference (p < .05) in Cmax, tmax, and mean residence time between implant I and implants II and III, but no difference in the area under the plasma concentration time curves calculated by trapezoidal rule (AUC) among the implants. For pharmacodynamic studies, endogenous follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels were observed to be suppressed following implantation of all implants, which demonstrated that a therapeutically effective dose of EE2 had been delivered. Furthermore, the noncompartmental analysis of plasma FSH and LH profiles in rabbits showed a significant difference (p < .05) in AUC and the mean residence time between implant III and implants I and II. A good in vivo/in vitro relationship was observed between daily amounts of EE2 released and plasma profiles of EE2 for all implants. This relationship suggests that plasma profiles of EE2 could be predicted from in vitro measurement of daily amount of EE2 released. Therefore, performing in vitro drug release studies may aid in the development of an EE2 implant with the desired in vivo release rate.

Levonorgestrel concentrations during 7 years of continuous use of Jadelle contraceptive implants

Serum levonorgestrel concentrations were assayed in a multicenter, 7-year study of 199 users of Jadelle rod implants. We examined drug levels, patterns of changes, factors affecting drug levels, and concentrations at which pregnancies occurred. Mean levonorgestrel concentrations declined from 435 pg/mL at 1 month of use to 64% of that value (280 pg/mL) at the end of 3 years. Between the end of the third and fifth years neither mean nor median serum levels varied markedly. At 5 years the mean concentration was again 64% of the first month's mean. Declining levels were observed thereafter through the end of 7 years when the mean, 224 pg/mL, was 52% of the 1-month value. Last measured drug concentrations of women who became pregnant during Jadelle use had mean and median values of 152 and 144 pg/mL, respectively, and a maximum value of 180 pg/mL. Analyses indicated ponderal index, body weight, duration of use, and a single clinical center were the most important variables affecting measured levonorgestrel levels. Approximately one-third of assays in the sixth and seventh years were found to be below 180 pg/mL, suggesting that Jadelle levonorgestrel implants would not maintain sufficiently high levels of effectiveness against pregnancy after 5 years and that heavier women would then be at greater risk of pregnancy.

Implantable contraception

Although levonorgestrel contraceptive implants have been available for over 15 years, innovations have only recently led to a wider choice. These new implants offer easier insertion and removal and other advantages depending on the type of progestin. Implants prevent pregnancy by several mechanisms, including inhibition of ovulation and luteal function and alteration of cervical mucus and the endometrium. The high efficacy and ease of maintenance make implants an ideal contraceptive for many women, including adolescents, a population that uses implants infrequently but reports high satisfaction. Implants are appropriate for women who are breastfeeding, who have contraindications to estrogen, or who have diseases such as diabetes, hypertension, sickle cell anemia, or an HIV infection because implants have few metabolic or hematologic effects. Long-term use has not been associated with a decrease in BMD and generally leads to increased blood levels and iron stores. Women who wish to space their pregnancies appreciate the nearly immediate onset of action with insertion and the rapid termination of all effects with removal. All types of implants lead to menstrual changes and other side effects in some women. Adverse effects that occur in implant users more than the general population include headaches and acne. Women must be thoroughly counseled regarding the potential for menstrual alteration, side effects, and sexually transmitted infections if they do not use condoms. Despite their initial high cost, implants are a cost-effective method over several years, even when discontinued before the life of the implant.

Pharmacokinetics of Implanon. An integrated analysis

The aims of this paper were to present data on the pharmacokinetics, clearance, bioavailability, and in vivo absorption of etonogestrel (ENG); to present the results of a longitudinal analysis of the plasma concentration-time curves of ENG; and to present the results of a cross-sectional analysis on the association of body weight with serum ENG concentrations. Implanon had an absorption rate of almost 60 micrograms/day after 3 months, which slowly decreased to 30 micrograms/day at the end of 2 years. The bioavailability over this period of time was constant and close to 100%. The clearance remained around 7.5 L/h. With a bioavailability and clearance that remained constant, it was concluded that accumulation of ENG does not occur. After Implanon insertion, serum concentrations increased within 8 h to concentrations associated with ovulation inhibition. Maximum mean serum concentrations (Cmax) amounted to 813 pg/mL and the time (tmax) to reach Cmax was 4 days. After reaching Cmax, ENG serum concentrations declined to about 196 pg/mL at the end of the first year, followed by a slow decline to 156 pg/mL at the end of the third year. After removal of Implanon, serum ENG concentrations declined to levels less than the detection limit of the assay (20 pg/mL) within 1 week. Lower body weight was associated with higher serum ENG concentrations.

Pharmacokinetics of etonogestrel released from the contraceptive implant Implanon

Eight healthy women between 22 and 40 years of age participated in this prospective open study of 2 years' duration. Either on or between days 1 to 7 of a spontaneous menses, an intravenous bolus dose of 150 micrograms etonogestrel (3-ketodesogestrel) was given. During days 1-5 of a subsequent spontaneous cycle, the single-rod contraceptive implant (Implanon) was inserted in the upper arm of the volunteer. One year after placement of the implant, another intravenous bolus dose was given (implant in place), and a third bolus dose was given after 2 years, with the implant removed. Frequent serum sampling immediately after the intravenous dosings of etonogestrel was done to study the primary pharmacokinetic parameters, i.e., volume of distribution and clearance, allowing the calculation of the absorption rate and bioavailability of the implant, as a function of time. Results showed that etonogestrel released from Implanon has an absorption rate of approximately 60 micrograms/day after 3 months, which slowly decreases to 30 micrograms/day at the end of 2 years. The bioavailability over this period of time was constant and close to 100%. The clearance remained around 7.5 L/h. With a bioavailability and clearance that remained constant, it may be concluded that there is no accumulation of etonogestrel.

Sex hormone binding globulin and free levonorgestrel index in the first week after insertion of Norplant implants

Levonorgestrel has an inhibitory effect on sex hormone binding globulin (SHBG). This decrease in SHBG leads to an increase in the free levonorgestrel index (FLI), which has a stronger biological effect. The interaction between serum levels of levonorgestrel and SHBG in long-term users of Norplant implants has been described. This study was designed to understand the same interaction immediately after the insertion of the implants, in a group of 16 women, sampled at 0 and 6 h and at 1, 3, and 7 days after Norplant implant insertion. Peak serum levonorgestrel levels were achieved at 24 h after insertion, remaining stable on day 3 and decreasing by > 10% by day 7. SHBG did not change during the first 24 h, but decreased by 19% and 60% on days 3 and 7, respectively. FLI more than doubled from day 1 to day 7 after insertion. The large decrease in SHBG and doubling of FLI is not followed by a similar reduction in levonorgestrel, which is hard to explain without an increase in the release rate of the steroid from the capsule.