Medical eligibility criteria for new contraceptive methods: combined hormonal patch, combined hormonal vaginal ring and the etonogestrel implant

Vaginal Administration of Contraceptives

While contraceptive drugs have enabled many people to decide when they want to have a baby, more than 100 million unintended pregnancies each year in the world may indicate the contraceptive requirement of many people has not been well addressed yet. The vagina is a well-established and practical route for the delivery of various pharmacological molecules, including contraceptives. This review aims to present an overview of different contraceptive methods focusing on the vaginal route of delivery for contraceptives, including current developments, discussing the potentials and limitations of the modern methods, designs, and how well each method performs for delivering the contraceptives and preventing pregnancy.

Thermo-reversible in situ forming implant with nanostructured lipid carriers (NLC) as a delivery system for the administration of estradiol valerate

A thermo-reversible in situ forming implant, based on the combination of Pluronic® F-127 and Pluronic® F-68 with nanostructured lipid carriers (NLC), was formulated with the aim of achieving the sustained release of estradiol valerate (EV). EV-loaded NLC, prepared by the hot high-pressure homogenization technique, presented an entrapment efficiency of 90 ± 2.9 %, a particle size (PS) of 122 ± 11.2 nm, a polydispersity index (PDI) of 0.344 ± 0.07, and a zeta potential (ZP) of - 10.5 ± 1.3 mV. Once obtained, NLC were then included in a thermo-reversible gel (EV-loaded NLC gel), which was characterized by its rheological behavior, gelation temperature, and injectability. The in vitro release tests showed that the EV-loaded NLC gel delayed the release significantly, in comparison with a solution of the drug and with the EV-loaded NLC. The EV-loaded NLC gel and a commercially available suspension containing estradiol were administered parenterally to rabbits. A 16.8-fold greater AUC and a 40-fold higher Cmax were obtained with the EV-loaded NLC gel, compared to the commercial suspension. A rapid initial release of EV in vivo, from the EV-loaded NLC gel, suggests that it is necessary to adjust the ratio of the copolymers or to include in the gel an additive that improves gelation time and gel strength, in order to achieve a sustained release. An interesting observation was that the in vitro profile, which has a three-phase behavior, coincides with what was observed in the in vivo study. Graphical abstract.

The effect of immediate postpartum compared to delayed postpartum and interval etonogestrel contraceptive implant insertion on removal rates for bleeding

OBJECTIVE

To determine whether the discontinuation rate of the etonogestrel contraceptive implant due to irregular vaginal bleeding among women with immediate postpartum insertion is increased compared to delayed postpartum and interval placement.

STUDY DESIGN

This retrospective cohort study compared women who underwent immediate postpartum etonogestrel contraceptive implant insertion (within 96 h of delivery) to delayed postpartum (6 to 12 weeks postpartum) and interval insertion between January 2008 and December 2010. Charts were reviewed for date and reason for removal. A chi-squared test was used to compare discontinuation due to bleeding between cohorts. Baseline characteristics predictive of implant removal were evaluated by simple logistic regression.

RESULTS

There were 259 women in the immediate postpartum group, 49 in the delayed postpartum group and 106 in the interval group. Average age at insertion was 22.6 (±5.5) years. Overall, 19.3% of women in the immediate postpartum group requested removal due to irregular bleeding compared to 18.4% in the delayed postpartum group [odds ratio (OR) 1.06, 95% confidence interval (CI) 0.48-2.33] and 20.8% in the interval group (OR 0.91, 95% CI 0.52-1.60). There was no difference between groups in premature removal rates for any side effect. There were no sociodemographic or clinical characteristics predictive of removal in any group.

CONCLUSION

One-fifth of etonogestrel contraceptive implant users requested premature removal due to irregular bleeding. Immediate postpartum implant insertion does not lead to increased removal rates and may help reduce unintended pregnancy. Mechanisms to help women manage irregular bleeding due to the implant are needed.

IMPLICATIONS

Immediate postpartum insertion of the etonogestrel contraceptive implant does not lead to increased removal rates due to vaginal bleeding compared to delayed postpartum or interval insertion. Immediate postpartum implant insertion may increase uptake of long-acting reversible contraception and help reduce short interpregnancy intervals and unintended pregnancy.

Current status of contraceptive vaginal rings

Contraceptive vaginal rings (CVR) offer a new, effective contraceptive option, expanding the available choices of hormonal contraception. Various ring prototypes have been evaluated: progestin-only rings and combined progestin-estrogen rings, as well as different combination of progestins and estrogens. The progestin-only ring is intended for continuous use, whereas the combined ring has been designed for cyclic 3-week in/1-week out use, although several studies have explored alternative schemes of extended use. However, only two ring designs have reached the market: NuvaRing, a 1-month combined ring that releases etonogestrel and ethinylestradiol, and Progering, a 3-month progesterone-releasing ring for use in lactating women. A one year Nestorone/ethinyl estradiol CVR is approaching the final stages of development, as the Population Council is preparing to submit a new drug application to the Food and Drug Administration. The main advantages of CVRs are their effectiveness (similar or slightly better than the pill), ease of use without the need of remembering a daily routine, user ability to control initiation and discontinuation, nearly constant release rate allowing for lower doses, greater bioavailability and good cycle control with the combined ring, in comparison with oral contraceptives. Current prototypes in development include rings releasing progesterone receptor modulators, which would provide estrogen-free contraception, as well as combined rings releasing estradiol, instead of ethinyl-estradiol, providing a safer profile. Furthermore, intensive efforts towards developing dual protection rings, providing both contraception and protection against reproductive tract infections, offer hope that this greatly needed technology will soon undergo clinical testing and will be in the hands of women worldwide in the near future.

Clinical practice: Contraception in adolescents

In affluent societies, median age at menarche has dropped to below 13 years. Younger age at menarche is associated with earlier sexual activity. To avoid unintended teenage pregnancies, barriers to contraception provision must be kept low, i.e. availability without prescription or through a low-threshold prescription system, low-cost options and long-term prescriptions or easy refills. Since many adolescents are (over)concerned about side effects, these should be addressed. A gynaecological examination prior to prescription is no longer recommended. All effective reversible contraceptive methods are available to adolescents: user-based hormonal contraceptives, trimonthly depot medroxyprogesterone acetate (DMPA), and long-acting reversible contraception (LARC). User-based hormonal contraceptives carry a small absolute risk of venous thromboembolism (~4 per 10,000 patient-years), but the risk is more than tenfold higher among young women with an inherited clotting defect. DMPA reduces bone mineral accumulation, but this is a reversible effect; the metabolic risks, including weight gain and insulin resistance, appear to be greater. LARC, including intrauterine contraceptive devices and the progestogen-containing implant, is gaining popularity among teenagers; abnormal bleeding is the main side effect. Any effective contraceptive should preferably be combined with consistent condom use to prevent sexually transmitted infections ("the double Dutch").

Vaginal ring contraception

The contraceptive vaginal ring is a relatively new combined hormonal contraceptive method. Ethinyl estradiol and etonogestrel are rapidly absorbed through the vaginal epithelium and result in a steady serum concentration. Studies have demonstrated that the efficacy and safety of the ring are equivalent to oral contraceptives (OCs). Patients report being highly satisfied with the vaginal ring and report fewer systemic side effects than do OC users. The ring provides effective cycle control as well as symptom relief for women with menorrhagia, dysmenorrhea and polycystic ovarian syndrome. A new combined contraceptive ring containing Nestorone and ethinyl estradiol is currently being investigated in a Phase 3 trial. A progesterone-releasing vaginal ring appropriate for lactating women is available in Chile and Peru. Recent studies have demonstrated that vaginal rings can also be effective means of delivering antiretroviral drugs that provide protection from HIV.

Implanon: a new contraceptive implant

Women who cannot use hormonal contraception containing estrogen have a variety of progestin-only contraceptive methods from which to choose. Implanon is a new single-rod progestin-only contraceptive implant that is easily inserted and can remain in place for up to 3 years. It is highly effective with a rapid onset of action and an equally rapid return of fertility once removed. Counseling is important to help women decide if this method is appropriate for their needs.

Hormonal Management of Migraine Associated With Menses and the Menopause: A Clinical Review

OBJECTIVE

This article reviews hormonal strategies used to treat headaches attributed to the menstrual cycle or to peri- or postmenopausal estrogen fluctuations. These may occur as a result of natural ovarian cycles, or in response to the withdrawal of exogenously administered estrogen.

BACKGROUND

A wide variety of evidence indicates that cyclic ovarian sex steroid production affects the clinical expression of migraine. This has led to interest in the use of hormonal treatments for migraine.

METHODS

A PubMed search of the literature was conducted using the terms "migraine,""treatment,""estrogen,""hormones,""menopause," and "menstrual migraine." Articles were selected on the basis of relevance.

RESULTS

The overarching goal of hormonal treatment regimens for migraine is minimization of estrogen fluctuations. For migraine associated with the menstrual cycle, supplemental estrogen may be administered in the late luteal phase of the natural menstrual cycle or during the pill-free week of traditional combination oral contraceptives. Modified contraceptive regimens may be used that extend the duration of active hormone use, minimize the duration or extent of hormone withdrawal, or both. In menopause, hormonally associated migraine is most likely to be due to estrogen-replacement regimens, and treatment generally involves manipulating these regimens. Evidence regarding the safety and efficacy of these regimens is limited.

CONCLUSIONS

Hormonal treatment of migraine is not a first-line treatment strategy for most women with migraine. Evidence is lacking regarding its long term harms and migraine is a contraindication to the use of exogenous estrogen in all women with aura and those aged 35 or older. The harm to benefit balances of several traditional nonhormonal therapies are better established.