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Query: UMLS:C0338671 (Steroids)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Progestin implants for contraception are highly effective, safe, and the most convenient choice for many women. Progestin implants currently on the market, preparing for launch, or under investigation are reviewed here. Their basic galenic and pharmacokinetic features, as well as their contraceptive effectiveness, are described. The first progestin-only contraceptive implant placed on the market was Norplant, a multiunit system. Since then, several single- and double-rod implants have been developed, each using one of four different progestins: levonorgestrel, etonogestrel, Nestorone and nomegestrol acetate. Jadelle is similar to Norplant but consists of only two, rather than six, Silastic rods to simplify insertion and removal; nevertheless, levonorgesterel serum levels are identical, and performance is the same for both systems. The single implant systems reviewed here are: Implanon with a 3-year duration; Nestorone implants for breast feeding and non-breast feeding women lasting up to 2 years; and Uniplant, which is effective for 1 year. The advantages and disadvantages of progestin implants, the importance of counseling for increasing user satisfaction, and the future outlook for this contraceptive method are also discussed.
Steroids
PMID:Progestin implants. 1110 76

In the 1980s and 1990s, the litigious climate in the US had a catastrophic effect on sales of many major contraceptives. Although oral contraceptives escaped controversy, the intrauterine device (IUD) and Norplant(R) were two targets of damaging litigation. The IUD was withdrawn from the market in 1985. Since 1994 when the attacks began against Norplant, its US sales have dramatically declined, even though no fault has been found in the method or its development. In general, pharmaceutical companies were extremely hesitant to develop new contraceptives during this period. The bleak outlook, however, began to shift in the late 1990s, as fertility rates began to decrease worldwide and contraceptive users increased. By 2025, 2500 million women will comprise the customer base for contraception. Global pharmaceutical companies are now participating in expanding markets overseas and have launched and continue to develop a range of new long-term reversible, and highly effective, contraceptive products outside the traditional oral contraceptive field. Two new contraceptives on the way to the US market are: Mirena, a levonorgestrel-releasing intrauterine system manufactured by Schering-Leiras; and Implanon, a single implant system manufactured by Organon of the Netherlands. Other birth control methods soon to be launched include: emergency contraceptives, the contraceptive patch, monthly contraceptive injections, mifepristone for medical abortion, and modified oral contraceptives.
Steroids
PMID:The return of the pharmaceutical industry to the market of contraception. 1110 81

Steroids can be administered in at least five different ways: injectables; hormone-releasing intra-uterine devices (IUDs); implants; vaginal rings; and pills. Progestogens which are synthetic steroids, are used as the main bioactive substances. Different progestogens are effective for different periods of time. Progestins in daily oral pills are effective for 24 hours. The effectiveness of a progestogen can be prolonged by incorporating it in a sustained-release system that gradually releases the hormone; therefore they can be effective up to 5 years or more. Two progestogen-only injectables are widely available in the family planning programmes, (DMPA and NET-EN) and two combined injectables, Cyclofem (DMPA + EC), and Mesigyna (NET-EN + EV). The ring is placed by the woman in her vagina, where it gradually releases hormone. Implantable contraceptives are placed just under the skin on the inside of the woman's arm. Implant capsules release the progestogen at a slow, steady rate. There are three implantables available in the market: Implanon; Norplant; and Jadelle. They are effective for 1-5 years, but then must be replaced. Natural and synthetic progestogens were first added to IUDs in the early 1970s. The main problem of long-acting progestogens is the disruption of the menstrual cycle.
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PMID:Long-acting progestogens. 1204 60

Research into contraception is producing new techniques that involve everything from vaccinations to nasal sprays. Steroids are the basis of the conventional contraceptive pill and much current research is on alternative ways of introducing the same drugs into the woman's reproductive system. Norplant is 1 approach. It involves implanting 6 tiny silicone-rubber tubes just beneath the skin of a woman's underarm. The tubes contain a drug, widely used as an ingredient of the contraceptive pill, which is slowly released from the tubes over a period of 5 years. It is understandable that much contraceptive research is focused on the womb. The brain, however, seems a strange place to be concerned with when trying to prevent conception. But it is the brain that controls a woman's ovulation by sending signals to the reproductive system via the pituitary gland. And now it is possible to synthesize chemicals which, when given in the form of a nasal spray, will inhibit ovulation by mimicking the brain's signals to the pituitary gland. It may even be possible to develop drugs which act directly on parts of the brain itself--a prospect we should be aware of, whether we would approve of it or not. There has been such an explosion of knowledge of the neural transmission systems that this may not be so far-fetched as it sounds. Research in China tends to concentrate more on naturally occurring substances--like a new form of female sterilization which involves not anesthetics or surgery but a substance called "mucilage"--1 of the ingredients of birds-nest soup. If mucilage is passed through the cervix into the fallopian tubes it causes them to block up and so prevents the passage of the ovum. There is a Western "high-tech" alternative to this, called methylcyanoacrylate--you might be more familiar with it as "superglue" or "crazy glue." Used carelessly it can stick your fingers together, but this tendency to join human tissues can be more productively used to block up the fallopian tubes. The Chinese are also looking at another natural substance as the basis of the possible "male pill." This is gossypol which occurs in cottonseed. A major reason why most research has been focused on contraception for women is that men present problems of quite a different order of magnitude. While a woman only ovulates once every 28 days or so, male sperm are produced continuously, with 200-400 million of them in each ejaculation. But drugs based on gossypol, which seems to have the effect of reducing the sperm count, may be the answer. Under the auspices of the World Health Organization, research on gossypol and other plants with contraceptive potential is now going on over all the world. Some 350 have been put under the microscope so far and about 30 look worth pursuing.
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PMID:Fertile inventions: new contraceptive techniques. 1226 4

Expression of tissue factor (TF), the primary initiator of hemostasis via thrombin formation, is induced during progesterone (P4)-stimulated decidualization of human endometrial stromal cells (HESCs), and remains elevated in decidualized HESCs of luteal and gestational endometrium. In HESC monolayers, progestins elevate TF mRNA and protein levels and estradiol (E2) plus progestin further enhance TF levels for weeks despite no response to E2 alone. This in vitro model mimics the chronic differential ovarian steroid upregulation of TF levels associated with in vivo decidualization. After incubation of HESCs with E2 plus progestin to elevate TF expression, the antiprogestin RU486 completely reversed this upregulation. Thus, progesterone withdrawal transformed decidualization-associated hemostasis of the luteal phase endometrium to the hemorrhagic milieu of menstruation. Transient transfections with TF promoter constructs containing SP and EGR-1 binding sites before and after inactivation by site-directed mutagenesis revealed that Sp1 mediates basal and progestin-enhanced TF transcriptional activity. Progesterone receptor involvement in TF expression was further confirmed since RU486 was a pure antagonist of progestin-enhanced TF mRNA and protein expression, and progestin-enhanced, but not basal, Sp1-mediated transcriptional activity. Enhanced TF mRNA and protein levels in HESCs require co-incubation with progestin and epidermal growth factor receptor (EGFR) agonist indicating that the EGFR mediates progestin-enhanced TF expression. A peak in the primary angiogenic agent, vascular endothelial growth factor (VEGF) in luteal phase endometrium may be indirectly regulated by P4. Neither E2, nor progestin, nor E2 plus progestin affected VEGF expression in glandular epithelial and stromal cells, whereas thrombin enhanced VEGF mRNA and protein levels in decidualized HESCs, but not in the epithelial cells. Transudation of clotting factors to perivascular decidual cell TF in the luteal phase would generate thrombin, enabling it to act as an autocrine enhancer of VEGF in decidualized HESCs. Abnormal uterine bleeding complicates long-term progestin only contraceptive use. After Norplant administration, endometrial VEGF levels are elevated and TF levels are selectively enhanced in decidualized HESCs at bleeding sites. Over-expressed VEGF causes blood vessels to become leaky, increasing clotting factor access to decidualized HESC-expressed TF to promote feed-forward thrombin and VEGF formation. Since thrombin and VEGF induce angiogenesis via separate endothelial cell receptors, they may synergize to elicit aberrant angiogenesis, and ultimately lead to focal bleeding.
Steroids 2003 Nov
PMID:Progestin-regulated expression of tissue factor in decidual cells: implications in endometrial hemostasis, menstruation and angiogenesis. 1466 77

Depo-medroxyprogesterone acetate (DMPA) is an effective injectable contraceptive with worldwide availability. However, it is associated with a high incidence of breakthrough bleeding (BTB) during the first 6 months of use which often leads to discontinuation. Mifepristone is a progesterone receptor antagonist that has been demonstrated to decrease BTB caused by the levonorgestrel subdermal implant (Norplant). The purpose of this study was to determine if mifepristone would decrease BTB in new starters of DMPA. Twenty regularly cycling women who were new starters of DMPA were randomized to receive 50 mg of mifepristone or placebo every 2 weeks for 24 weeks. Percent days of BTB and number of cycles with bleeding intervals > or =8 and > or =14 days were evaluated using daily bleeding diaries. Ovulation was determined by measuring thrice-weekly urinary metabolites of estrogen and progesterone. Endometrial concentrations of ER and PR were determined by immunohistochemistry. Mifepristone significantly decreased the percent days of BTB and the number of cycles with prolonged bleeding intervals when compared to placebo. No subject ovulated in either group. ER immunostaining increased and PR immunostaining decreased after mifepristone treatment. In conclusion, a 50 mg dose of mifepristone taken every 2 weeks decreases the incidence of BTB in new starters of DMPA. This effect may be due to modulation of endometrial estrogen and progesterone receptors.
Steroids 2003 Nov
PMID:Mifepristone for the prevention of breakthrough bleeding in new starters of depo-medroxyprogesterone acetate. 1466 6

Women with polycystic ovary syndrome (PCOS) have a 2.7-fold increased risk for developing endometrial cancer. A major factor for this increased malignancy risk is prolonged exposure of the endometrium to unopposed estrogen that results from anovulation. Additionally, secretory endometrium of some women with PCOS undergoing ovulation induction or receiving exogenous progestin exhibits progesterone resistance accompanied by dysregulation of gene expression controlling steroid action and cell proliferation. Endometrial surveillance includes transvaginal ultrasound and/or endometrial biopsy to assess thickened endometrium, prolonged amenorrhea, unopposed estrogen exposure or abnormal vaginal bleeding. Medical management for abnormal vaginal bleeding or endometrial hyperplasia consists of estrogen-progestin oral contraceptives, cyclic or continuous progestins or a levonorgestrel-releasing (Mirena) intrauterine device. Lifestyle modification with caloric restriction and exercise is appropriate to treat obesity as a concomitant risk factor for developing endometrial disease. An increased risk of ovarian cancer may also exist in some women with PCOS. There are strong data to suggest that oral contraceptive use is protective against ovarian cancer and increases with the duration of therapy. The mechanism of this protection may be through suppression of gonadotropin secretion rather than the prevention of "incessant ovulation". There is no apparent association of PCOS with breast cancer, although the high prevalence of metabolic dysfunction from obesity is a common denominator for both conditions. Recent data suggest that the use of metformin may be protective for both endometrial and breast cancer. There are insufficient data to evaluate any association between PCOS and vaginal, vulvar and cervical cancer or uterine leiomyosarcoma.
Steroids 2013 Aug
PMID:Cancer risk and PCOS. 2362 28