Contraceptive efficacy of bioabsorbable pellets of norethindrone (NET) as subcutaneous implants: phase II clinical study

The Intrauterine Device in Women with Diabetes Mellitus Type I and II: A Systematic Review

Background. Women with diabetes mellitus type I and type II need effective contraception for personal and medical reasons. Long acting reversible contraceptive (LARC) methods are among the most efficient and cost-effective methods. Study Design. We searched the Popline, PubMed, and clinicaltrials.gov databases from 1961 to March 2013 for studies on the efficacy of the IUD in diabetic women and the possible changes it may produce in laboratory parameters. Studies of at least 30 subjects with DM1 or DM2 who were studied for 6 to 12 months depending on the method of analysis were eligible. Results. The search produced seven articles which gave event rate efficacy evaluable results and three which evaluated the effect of the IUD on laboratory parameters. One of the earlier efficacy studies showed an abnormally high pregnancy rate which sparked a controversy which is discussed in the Introduction section. The remaining 6 studies produced acceptable pregnancy rates. The three laboratory studies showed that the copper and levonorgestrel releasing IUD/IUS do not affect the diabetic state in any way. Conclusions. The copper bearing and levonorgestrel releasing IUDs are safe and effective in women with diabetes type I and diabetes type II although the evidence in the latter is limited.

Biodegradable norethindrone (NET:cholesterol) contraceptive implants: phase II-A: a clinical study in women

Safety, contraceptive efficacy and biodegradability of subdermal norethindrone (NET)-cholesterol implants (Anuelle) were investigated in 19 healthy, sexually active women. Mean serum NET levels in women with four and five pellets, containing 174 mg and 266.5 mg NET, showed a "burst-effect" of 3.17 and 3.71 ng/ml, respectively, within 24 h post implantation. Subsequently, for the four- and five-pellet groups, respectively, the levels declined from 0.75 to 0.40 ng/ml and 1.05 to 0.61 ng/ml during the months 12-15, from 0.40 to 0.11 ng/ml and 0.61 to 0.25 ng/ml up to month 36. The serum NET levels were undetectable at 36 months and beyond, indicating complete biodegradability of NET pellets. Serum E2 levels remained within normal limits (> 50 pg/ml), whereas serum P indicated anovulatory cycles in 78% of the four-pellet group and 99% of the five-pellet group. FSH and LH levels were subnormal and acyclic. Plasma lipids showed reduced total and LDL cholesterol and triglycerides. HDL cholesterol remained unchanged. Drug-related adverse effects were essentially limited to irregular bleeding. There were no pregnancies in either group.

Contraceptive efficacy, pharmacokinetics, and safety of Annuelle biodegradable norethindrone pellet implants

OBJECTIVE

To evaluate the contraceptive efficacy, pharmacokinetics, and safety of two formulations of Annuelle (Endocon, Inc., South Walpole, MA) biodegradable norethindrone (NET) SC pellet implants.

DESIGN

Prospective observational study.

SETTING

Two clinical sites in the United States.

PATIENT(S)

Thirty-nine healthy, fertile, sexually active women.

INTERVENTION(S)

Nineteen women received a four-pellet system containing 174 mg NET; 20 women received a five-pellet system containing 266.5 mg NET.

MAIN OUTCOME MEASURE(S)

Contraceptive efficacy, median serum NET levels, adverse events.

RESULT(S)

No pregnancies were observed in 293 woman-months in the four-pellet group or in 375 woman-months in the five-pellet group. An initial burst in median serum NET levels occurred in the first 24 hours postinsertion followed by a steady decline over the next 3 years. Norethindrone levels varied considerably among women. The main side effect was bleeding abnormalities, which persisted in half the participants for up to 2 years. No serious adverse events were reported that were related to the pellets. Pellet insertion and removal generally were uncomplicated.

CONCLUSION(S)

Annuelle shows potential as an effective, safe contraceptive with distinct advantages over other long-acting agents, because it is biodegradable but can be removed if problems arise or if fertility is desired.

Hormonal implants: contraception for a new century

Subdermal implants are contraceptive systems that release low, stable amounts of synthetic progestins from Silastic or other materials for periods of months to several years. Unlike other hormonal delivery systems, they do not cause unnecessary peaks in progestin levels and do not use estrogens, and thus their health risks are minimal. Norplant has been studied more extensively than any other subdermal contraceptive implant. More than 60,000 women have participated in clinical trials, which demonstrated that this approach is one of the most effective reversible contraceptive methods available (1% pregnancy rate in 5-year users). The implant also reduces the incidence of ectopic pregnancy to a level much below noncontraceptive users and about equivalent to TCu380A intrauterine device users. Exposure to the sustained, low dose of levonorgestrel delivered by Norplant has shown only minor metabolic changes. Side effects are minor but often bothersome, causing some discontinuation of the method. First-year continuation rates range from 76% to 90%. Fertility return after discontinuation is prompt. Difficulty in removal of the implant capsules by the less experienced practitioner has motivated researchers to develop systems that are easier to use, less obvious under the skin, and biodegradable. The Norplant 2 system is faster, easier, and less painful to insert and remove. Implants under investigation release desogestrel and other progestins; Capronor and subdermal norethindrone pellets are biodegradable systems.

Tissue response to bioerodible, subcutaneous drug implants: a possible determinant of drug absorption kinetics

The fibrous tissue compartments that develop in response to the subcutaneous implantation of bioerodible heat-fused rods of norethindrone and cholesterol (85 and 15%, respectively) were studied by light and electron microscopy at various intervals after implantation to determine whether the biological inflammatory response may play a role in drug absorption. Thirty-five regularly menstruating, sterilized (tubal ligation), healthy females each received four Annuelle rods. The microanatomy of seven of the largest implants (135 mg norethindrone) was studied. A dense fibrous biological compartment was found to surround each rod. By light microscopy no abnormal tissue response was revealed. Scanning and transmission electron microscopy showed that the surfaces of the rods were covered by a cellular matrix of mononuclear cells. The fibrous compartment was composed of a loose cellular bed immediately surrounding the norethindrone rod, a dense fibrous connective tissue envelope containing blood and lymphatic vessels, and an outer fatty connective tissue layer. Transmission electron microscopy confirmed that the cellular tissue immediately surrounding the rods was composed mainly of lipid laden macrophages. Norethindrone levels in tissue capsules at 3 and 10.5 months were 0.05 and 8.4% by weight, respectively. These observations suggest that the local inflammatory response plays a role in the active processing of this delivery system. This picture is qualitatively different from the general view of the fibrous capsule as a simple rate limiting membrane. The effects observed in this study suggest that a more complex, functional biological system develops in response to the subcutaneous introduction of a drug delivery device.

Contraceptive efficacy of norethindrone encapsulated in injectable biodegradable poly-dl-lactide-co-glycolide microspheres: phase II clinical study

Contraceptive efficacy of injectable norethindrone (NET) microspheres of 90 day duration was evaluated for 6 months: nine women received two injections of 65 mg each and eight received two injections of 100 mg each with 90 days between each injection. Average serum NET levels were 5 to 9 ng/mL on the day after injection and subsequently remained at 1 to 3 ng/mL. With 65 and 100 mg doses, respectively, 36% and 25% of cycles had normal bleeding patterns, 36% and 48% were amenorrheic, and the remaining 28% and 27% had prolonged bleeding. Also, 56% and 40% of cycles showed increased spotting for the 65 mg and 100 mg dose, respectively. There was no incidence of pregnancy or serious side effects. The mean serum NET concentration returned to RIA nonspecific basal levels 100 days after the second injection. Women returned to ovulatory cycles between days 100 to 115 after the second injection.