Progestins in oral contraceptives

Women of reproductive potential prescribed efavirenz should be counseled on its potentially teratogenic effects and the importance of birth control. Additionally, nevirapine, nelfinavir, ritonavir, lopinavir/ritonavir, and tipranavir/ritonavir have been shown to decrease the concentrations of estrogens and/or progestins in oral contraceptives, which could lead to failure.2 For patients prescribed these drugs, barrier forms of contraception are preferred to prevent pregnancy. DepoProvera may be... 

Several progestins are used in combination products. Norgestrel (Ovrette) is a mixture of active and inactive enantiomers levonorgestrel (Norplant) is the active enantiomer. Levonorgestrel and norethindrone are the most potent synthetic progestins in oral contraceptive preparations. 

The amount of estrogens (and progestins) in oral contraceptives has been markedly decreased, significantly diminishing the risks associated with their use. 

Pharmacological Effects of Progestins Used in Oral Contraceptive ... 

Therapeutic indications for the progestational drugs based on pregnanes described above are rather limited. This is particularly true when compared to the reduced estrane-based nor compounds that are used in oral contraceptives. This circumstance, combined with the availability of the half-dozen or so C-19 progestins, posed as a disincentive to further research on the synthesis of new compounds. This is reflected in the pubhcation dates of reports on the synthesis of these compounds. 

Menendez, J. A., Oza, B. P., Colomer, R. and Lupu, R., The estrogenic activity of synthetic progestins used in oral contraceptives enhances fatty acid synthase-dependent breast cancer cell proliferation and survival, Int J Oncol 26 (2005a) 1507-1515. 

Synthetic estrogens have also been developed, and these are often used in oral contraceptives in combination with synthetic progestins. A very potent synthetic estrogen is the compound called ethynylestradiol or novestrol ... 

As of 1994, there were approximately 47 progestin-containing contraceptive dmg formulations sold in the United States for use as oral contraceptives (Table 3). In addition, there are three nonoral contraceptive formulations containing progestins ie, one injectable (Depo-Provera), one as an intrauterine device (lUD) (Progestasert), and one implantable (Norplant). Of the oral formulations, all but two also contain an estrogen component, ethynylestradiol. 

The 1950s and 1960s saw the development of orally active progestins based on the synthesis of steroids that lack the C19-angular methyl substituent (19-norsteroids). The commercial production of these compounds for the regulation of menstmal disorders began in 1957, and for oral contraception in 1960. 

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