Role of the levonorgestrel intrauterine system in effective contraception

Abstract

Norgestrel, a synthetic progestin chemically derived from 19-nortestosterone, is six times more potent than progesterone, with variable binding affinity to various steroid receptors. The levonorgestrel-releasing intrauterine system (LNG IUS) provides a long-acting, highly effective, and reversible form of contraception, with a pearl index of 0.18 per 100 women-years. The locally released hormone leads to endometrial concentrations that are 200–800 times those found after daily oral use and a plasma level that is lower than that with other forms of levonorgestrel-containing contraception. The contraceptive effect of the LNG IUS is achieved mainly through its local suppressive effect on the endometrium, leading to endometrial thinning, glandular atrophy, and stromal decidualization without affecting ovulation. The LNG IUS is generally well tolerated. The main side effects are related to its androgenic activity, which is usually mild and transient, resolving after the first few months. Menstrual abnormalities are also common but well tolerated, and even become desirable (eg, amenorrhea, hypomenorrhea, and oligomenorrhea) with proper counseling of the patient during the choice of the method of contraception. The satisfaction rates after 3 years of insertion are high, reaching between 77% and 94%. The local effect of the LNG IUS on the endometrium and low rates of systemic adverse effects have led to its use in other conditions rather than contraception, as for the treatment of endometrial hyperplasia, benign menorrhagia, endometriosis, adenomyosis, and uterine fibroids.

Use of the Levonorgestrel Intrauterine Device in Women With Type 2 Diabetes

“…We expect the same to be true for women with type 2 diabetes due to low systemic absorption of the progestin hormone in the LNG-IUD (19). Although DMPA has been associated with negative effects on cholesterol, weight gain, and thrombosis, the same has not been found for other progestin-based contraceptives, including the LNG-IUD (20,21). Furthermore, a small case series of 11 women with type 2 diabetes using the LNG-IUD found little or no influence on glycemic control in their 12 months of follow-up (22).…”

Depressive Disorder With Panic Attacks After Replacement of an Intrauterine Device Containing Levonorgestrel: A Case Report

“…pre-/peri-or postmenopausal periods, may considerably increase the risk of psychiatric ADRs. Alternatively, it is of note that locally released LNG by IUSs lead to endometrial concentrations that are 200-800 times those found after daily oral use (25). Considering the endometrial thinning after the prolonged use of LNG-IUS as in our case, one may assume an altered pharmacokinetic profile of LNG-IUS within the first weeks after the insertion of the second device, accompanied with higher risks of systemic effects.…”

Norethindrone is superior to combined oral contraceptive pills in short-term delay of menses and onset of breakthrough bleeding: a randomized trial

“…It functions as a contraceptive through its release of a progesterone agonist, thickening cervical mucus, expressing glycodelin A and thinning out the endometrial lining. IUDs also create an inflammatory environment in the uterine cavity [18]. By downregulating endometrial estrogen receptors, levonorgestrel induces endometrial thinning, glandular atrophy and stromal decidualization [18–20].…”

“…IUDs also create an inflammatory environment in the uterine cavity [18]. By downregulating endometrial estrogen receptors, levonorgestrel induces endometrial thinning, glandular atrophy and stromal decidualization [18–20]. These devices, which last 3–5 years can produce hypomenorrhea or amenorrhea over the long-term.…”