Subject(s)
Contraceptives, Oral, Synthetic/classification , Norethindrone/classification , Progesterone/classification , Terminology as Topic , Vasodilation/drug effects , Anticholesteremic Agents/administration & dosage , Atorvastatin , Contraceptives, Oral, Synthetic/administration & dosage , Drug Interactions , Estradiol/administration & dosage , Heptanoic Acids/administration & dosage , Humans , Norethindrone/administration & dosage , Pyrroles/administration & dosageSubject(s)
Contraceptives, Oral, Synthetic/adverse effects , Progesterone Congeners/adverse effects , Thromboembolism/chemically induced , Thrombophlebitis/chemically induced , Adolescent , Adult , Age Factors , Bias , Contraceptives, Oral, Synthetic/classification , Female , Humans , Odds Ratio , Progesterone Congeners/classificationSubject(s)
Androgens , Contraceptives, Oral, Synthetic , Progesterone , Progesterone/antagonists & inhibitors , Progestins , Androgens/chemical synthesis , Androgens/classification , Androgens/therapeutic use , Contraceptives, Oral, Synthetic/chemistry , Contraceptives, Oral, Synthetic/classification , Contraceptives, Oral, Synthetic/therapeutic use , Female , Humans , Methyltestosterone/chemistry , Methyltestosterone/classification , Methyltestosterone/therapeutic use , Mifepristone/chemistry , Mifepristone/classification , Mifepristone/therapeutic use , Progesterone/chemical synthesis , Progesterone/classification , Progesterone/therapeutic use , Progestins/chemical synthesis , Progestins/classification , Progestins/therapeutic use , United States , United States Food and Drug AdministrationABSTRACT
Oral contraceptives include two types of steroids; ethinyl-estradiol as the main estrogenic component which dose vary from 20 to 50 micrograms per tablet (mostly 30 to 35 micrograms) and progestins essentially derivatives of 19 nortestosterone. Derivatives of 19 norprogesterone such as nomegestrol acetate or ST 1435 are not used as oral contraceptives but are being evaluated through parenteral administration, e.g. implants or transdermal systems. The assessment of the pharmacological properties of these progestins indicate a high antigonadotropic and a high antiestrogenic properties for levonorgestrel and for the newer gestagens as well. Therefore very low doses are being used in the current oral contraceptives. However, there is a lower margin of security with the low dose contraceptives than with previous standard combinations and especially when concomitant medications are ingested such as enzyme-inducing agents. Selection of contraceptive methods should be discussed when specific co-medications are necessary.
PIP: Oral contraceptives (OCs) contain two types of steroids: ethinyl estradiol (the estrogenic component [20-50 mcg/pill]) and progestins derived essentially from 19-nortestosterone. The progestins derived from 19-norprogesterone (e.g., nomegestrol acetate or ST 1435) are not yet used in OCs, but are being evaluated for parenteral administration. The study of pharmacologic properties of progestins suggests that levonorgestrel and its derivatives have a powerful antigonadotropic and antiestrogenic effect, which allow them to be effective at very low doses in new OCs. These derivatives are desogestrel, gestodene, and norgestimate. The margin of safety for levonorgestrel and its derivatives is limited, especially when taken with other medication, however. Drugs that reduce the efficacy of OCs include rifampicin, antiepileptic drugs (e.g., phenobarbital), antibiotics (neomycin, lincomycin, and ampicillin), griseofulvin (an enzyme-inducing drug), antimalarials, and antacids. Thus, selection of contraceptive methods must be discussed when certain concomitant medications are required.
