Pharmacokinetics of once-a-month injectable contraceptives

Molecular Signatures of Immune Activation and Epithelial Barrier Remodeling Are Enhanced during the Luteal Phase of the Menstrual Cycle: Implications for HIV Susceptibility

The variable infectivity and transmissibility of HIV/SHIV has been recently associated with the menstrual cycle, with particular susceptibility observed during the luteal phase in nonhuman primate models and ex vivo human explant cultures, but the mechanism is poorly understood. Here, we performed an unbiased, mass spectrometry-based proteomic analysis to better understand the mucosal immunological processes underpinning this observed susceptibility to HIV infection. Cervicovaginal lavage samples (n = 19) were collected, characterized as follicular or luteal phase using days since last menstrual period, and analyzed by tandem mass spectrometry. Biological insights from these data were gained using a spectrum of computational methods, including hierarchical clustering, pathway analysis, gene set enrichment analysis, and partial least-squares discriminant analysis with LASSO feature selection. Of the 384 proteins identified, 43 were differentially abundant between phases (P < 0.05, ≥2-fold change). Cell-cell adhesion proteins and antiproteases were reduced, and leukocyte recruitment (interleukin-8 pathway, P = 1.41E-5) and extravasation proteins (P = 5.62E-4) were elevated during the luteal phase. LASSO/PLSDA identified a minimal profile of 18 proteins that best distinguished the luteal phase. This profile included cytoskeletal elements and proteases known to be involved in cellular movement. Gene set enrichment analysis associated CD4(+) T cell and neutrophil gene set signatures with the luteal phase (P < 0.05). Taken together, our findings indicate a strong association between proteins involved in tissue remodeling and leukocyte infiltration with the luteal phase, which may represent potential hormone-associated mechanisms of increased susceptibility to HIV.

IMPORTANCE

Recent studies have discovered an enhanced susceptibility to HIV infection during the progesterone-dominant luteal phase of the menstrual cycle. However, the mechanism responsible for this enhanced susceptibility has not yet been determined. Understanding the source of this vulnerability will be important for designing efficacious HIV prevention technologies for women. Furthermore, these findings may also be extrapolated to better understand the impact of exogenous hormone application, such as the use of hormonal contraceptives, on HIV acquisition risk. Hormonal contraceptives are the most widely used contraceptive method in sub-Saharan Africa, the most HIV-burdened area of the world. For this reason, research conducted to better understand how hormones impact host immunity and susceptibility factors important for HIV infection is a global health priority.

Bleeding patterns of adolescents using a combination contraceptive injection for 1 year

PURPOSE

This prospective observational study evaluated the bleeding patterns of adolescents receiving a monthly injectable contraceptive containing norethisterone enanthate 50 mg plus estradiol valerate 5 mg.

MATERIALS AND METHODS

The study enrolled 73 volunteers aged between 14 and 19 years; of these patients, 38 (52%) recorded their menstrual cycles during 1 year.

RESULTS

After 1 year of using the contraceptive, most of the 38 women (71.1%) had adequate menstrual patterns (two to four bleeding episodes; none lasting 10 days or longer; with a range of bleeding-free intervals not exceeding 17 days), 23.7% reported prolonged bleeding episodes, 2.6% had irregular bleeding and 2.6% had amenorrhea. Only 1 of the 38 teenagers is known to have discontinued the method due to bleeding. Among these 38 adolescents, dissatisfaction with bleeding patterns was not a frequent reason given for discontinuation of the monthly injectable contraceptive.

Comparative study of the effects of two once-a-month injectable contraceptives (Cyclofem® and Mesigyna®) and one oral contraceptive (Ortho-Novum 1/35®) on coagulation and fibrinolysis

A randomized controlled multicenter study was undertaken to monitor the effects on hemostasis of two once-a-month injectable contraceptive preparations, Mesigyna (50 mg norethisterone enanthate and 5 mg estradiol valerate) and Cyclofem (25 mg medroxyprogesterone acetate and 5 mg estradiol cypionate) in comparison with a well-known oral contraceptive (OC) Ortho-Novum 1/35 (norethisterone 1 mg and ethinyl estradiol 35 microg). A total of 378 volunteers from four centers (Bangkok, Hangzhou, Santiago and Singapore) were monitored. Blood sampling took place in one pretreatment cycle, the third and ninth injection intervals and one posttreatment cycle. In each of the three treatment groups, a rise in hemoglobin, and increases in platelet count and in prothrombin time were observed. With treatment there was a significant increase in activated partial thromboplastin time among Mesigyna users, no change among Cyclofem users and a significant decrease among OC users. OC use led to increases in plasma levels of fibrinogen, factor VII, factor X, plasminogen, protein C and decreases in plasma levels of t-PAI and antithrombin. Use of combined injectables induced no change (Cyclofem) or decreases (Mesigyna) in plasma levels of fibrinogen, factor VII, factor X and antithrombin. Use of both combined injectables led to decreases in protein C, slight decreases in plasminogen and increases in plasminogen and fibrinogen. Overall, the injectable preparations may be more beneficial than the oral preparation in not enhancing a hypercoagulable state because of the reduced synthesis of fibrinogen, factors VII and X; however, decreases in antithrombin and protein C, which are potent coagulation inhibitors, may raise some concern. Whether these changes can lead to modifications in the risk of arterial or venous disease can only be ascertained by conducting epidemiological studies.

Potential of norethisterone enanthate for male contraception: pharmacokinetics and suppression of pituitary and gonadal function

OBJECTIVE

Gestagens are known to suppress gonadotrophins in women and are currently also under investigation for the development of hormonal male contraceptives. The aim of the study was to assess the potential of norethisterone enanthate (NETE) for male contraception.

DESIGN AND MEASUREMENTS

The suppressive effect of a single injection of 200 mg NETE on serum gonadotrophins, serum testosterone, lipids, spermatogenesis, well-being and sexual function was evaluated in seven healthy men.

RESULTS

In this single dose study treatment was well tolerated by all volunteers. NETE led to a rapid, profound and significant suppression of serum LH (day 6 - day 10), FSH (day 2 - day 29), testosterone (day 1 - day 29 and day 35) and SHBG (day 6 - day 35). At study end sperm counts were significantly suppressed. Numbers of spontaneous erections (day 17, 23 and 26), number of sexual fantasies (day 20 and 23) as well as libido (day 20 and 26) were significantly decreased compared to baseline. All other parameters including lipids, augmented glucose, testicular volume and well-being showed no significant alterations.

CONCLUSION

Because of its strong, rapid and sustained suppression of serum FSH and testosterone norethisterone enanthate offers great potential for hormonal male contraception if combined with testosterone esters.

Cyclofem/Cyclo-Provera: emerging countries' perspective

Cyclo-Provera, the original name of the combination of 25 mg medroxyprogesterone acetate and 5 mg estradiol cypionate, later known as Cyclofem and hereafter referred to MPA/E2C, has proven its use-effectiveness (pregnancy rate less than 1%) in routine service delivery conditions. Overall, the life-table discontinuation rates at 1 year ranged from 33.5% to 71.8%. Only a third of total discontinuations were attributable to the injectable contraceptive method, thus raising the importance of service delivery issues related to its continued use. The results of introductory trials in Mexico, Indonesia, Thailand, Tunisia, Jamaica and, more recently, Brazil, Colombia, Chile and Peru have demonstrated that MPA/E2C is a highly effective contraceptive that could be offered as an alternative to current fertility regulation methods for many women around the world. In addition, the results of studies were the basis for the approval of MPA/E2C by local health authorities and its inclusion in the Ministries of Health Family Planning Programs.

New once-a-month injectable contraceptives, with particular reference to Cyclofem/Cyclo-Provera

Once-a-month injectable contraceptives containing a progestogen and an estrogen have been developed that disrupt vaginal bleeding patterns less than the widely used progestogen-only preparations. Pharmacokinetic studies were undertaken of dosages and ratios of the progestogens and the respective estrogens. In Phase III clinical trials, annual pregnancy rates were below 0.4% for Mesigyna (norethisterone enanthate/estradiol valerate, Schering AG, Berlin, Germany) and below 0.2% for Cyclofem (MPA/E2C) (medroxyprogesterone acetate/estradiol cypionate, Aplicaciones Farmaceuticas, SA, Mexico and PT Tunggal, Indonesia). More than two-thirds of women had predictable, regular cycles, and discontinuation due to bleeding-related problems occurred less than half as often as with progestogen-only injectables. With MPA/E2C, return to fertility is similar to that observed with other hormonal or intrauterine methods, and both products have little effect on lipids or hemostasis. Introductory trials of MPA/E2C in 12000 women with 100000 woman-months of experience confirmed the high efficacy of the product in routine use. The use of MPA/E2C in a non-reusable injection device, Uniject (Becton Dickinson, Franklin Lakes, NJ) is discussed. Once-a-month hormonal contraceptives have been shown to provide a safe contraceptive option for all women and an alternative for women who wish to use injectable formulations that cause less disruption in vaginal bleeding and minimal side effects.

Vaginal bleeding patterns in users of Perlutal, a once-a-month injectable contraceptive consisting of 10 mg estradiol enanthate combined with 150 mg dihydroxyprogesterone acetophenide. A trial of 5462 woman-months

Perlutal (other names: Topasel, Perlutan) is a once-a-month injectable contraceptive that contains 10 mg estradiol enanthate and 150 mg dihydroxyprogesterone acetophenide. A prospective trial was conducted in 216 women in Medellín, Colombia, over five years (5,462 woman-months) to establish the rates of the different vaginal bleeding patterns during the use of Perlutal, and to assess their relation with discontinuation of the Perlutal regimen. It was found that with the use of Perlutal, the duration of menstrual bleeding decreased from 3.9 to 2.7 days (p < 0.01), and that the incidence of dysmenorrhea decreased from 31% to 1.6% (p < 0.01). At one year of follow-up, the incidence of altered bleeding patterns was 5.1%. The discontinuation rate due to an altered bleeding pattern was 3.9%. It is concluded that the low incidence of altered bleeding patterns observed with the use of Perlutal leads to a low discontinuation rate among users.

Introduction of cyclofem once-a-month injectable contraceptive in Mexico

A large introductory study of Cyclofem, a once-a-month injectable contraceptive, was conducted in three Mexican provinces. A total of 3457 healthy women participated: 640 women from rural areas (community-based component) and 2817 women from urban and suburban areas (health center-based component). A total of 20,316 women-months of treatment experience were accumulated during a one year period. Cyclofem proved its use-effectiveness (pregnancy rate of 0.03%) and its safety under routine service conditions of family planning facilities in Mexico. The overall life table continuation rate at 1 year was 26.1%. Higher continuation rates were observed in the community-based component (36.6%) as compared to the health center component (23.7%). The most common reason for method discontinuation was change of address. Only 15% of the discontinuations were attributable to the injectable contraceptive method, with the overall 1 year discontinuation rate for bleeding problems (including amenorrhea) was < 11%. These observations underscore the importance of appropriate counseling and follow-up measures, providing convenient access to repeat injections, and other service delivery issues related to continuation of Cyclofem. The results of this trial have once again demonstrated that Cyclofem is a highly effective method with an acceptable side effect profile. In addition, the study provided the elements for its approval by local health authorities and its inclusion into the Ministry of Health Family Planning Program.