Birth Control Pills (Oral Contraceptives)

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GENERIC NAME:  birth control pills (also known as oral contraceptives, OCs, BCPs, oral contraceptive pills, or OCPs)

BRAND NAMES: see below

DRUG CLASS AND MECHANISM: Oral contraceptives (birth control pills) are medications that prevent pregnancy. They are one method of birth control. Oral contraceptives are hormonal preparations that may contain combinations of the hormones estrogen and progestin or progestin alone. Combinations of estrogen and progestin prevent pregnancy by inhibiting the release of the hormones luteinizing hormone (LH) and follicle stimulating hormone (FSH) from the pituitary gland in the brain. LH and FSH play key roles in the development of the egg and preparation of the lining of the uterus for implantation of the embryo. Progestin also makes the uterine mucus that surrounds the egg more difficult for sperm to penetrate and, therefore, for fertilization to take place. In some women, progestin inhibits ovulation (release of the egg).

There are different types of combination birth control pills that contain estrogen and progestin that are referred to as "monophasic," "biphasic," or "triphasic."

  • Monophasic birth control pills deliver the same amount of estrogen and progestin every day.

  • Biphasic birth control pills deliver the same amount of estrogen every day for the first 21 days of the cycle. During the first half of the cycle, the progestin/estrogen ratio is lower to allow the lining of the uterus (endometrium) to thicken as it normally does during the menstrual cycle. During the second half of the cycle, the progestin/estrogen ratio is higher to allow the normal shedding of the lining of the uterus to occur.

  • Triphasic birth control pills have constant or changing estrogen concentrations and varying progestin concentrations throughout the cycle. There is no evidence that bi- or triphasic oral contraceptives are safer or superior to monophasic oral contraceptives, or vice versa, in their effectiveness for the prevention of pregnancy.

PRESCRIPTION: Yes

GENERIC AVAILABLE: Yes, for some (see below)

PREPARATIONS: Tablets, various amounts (Please see the birth control article for non-oral contraceptives.)

STORAGE: All oral contraceptives should be stored between 15 C (59 F) and 30 C (86 F).

PRESCRIBED FOR: Birth control pills are prescribed to prevent pregnancy. When taken as directed, birth control pills fail in less than one in every 200 users over the first year of use.

Birth control pills also are prescribed to treat mid-cycle pain, which some women experience with ovulation. Birth control pills, while regulating the menstrual cycle, reduce menstrual cramps and heavy bleeding, and because of the reduced bleeding, they may prevent the anemia that can develop in some women. For this reason, they also are sometimes prescribed for a number of conditions that are characterized by excessive bleeding or painful menses.

Doctors sometimes prescribe higher doses of birth control pills for use as a "morning after" pill to be taken up to 72 hours after unprotected intercourse to prevent fertilization and pregnancy.

DOSING: Many of the birth control pills come in easy-to-use dispensers in which the day of the week or a consecutive number (1, 2, 3, etc.) is written on the dispenser with a corresponding tablet for each day or number.

For example, some Ortho-Novum dispensers are labeled "Sunday" next to the first tablet. Thus, the first tablet is to be taken on the first Sunday after menstruation begins (the first Sunday following the first day of a woman's period). If her period begins on Sunday, the first tablet should be taken on that day.

For birth control pills that use consecutive numbers, the first tablet (#1) is taken on the first day of the menstrual period (the first day of bleeding). Tablet #2 is taken on the second day and so on.

Still other packages instruct women to begin on day five of the cycle. For such products, women count from day one of their menstrual cycle (day one is the first day of bleeding). On the fifth day, the first tablet is taken. Tablets then are taken daily.




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