[Combined] oral contraceptive pill (OCP's, aka birth control pills) are drugs taken by mouth for birth control.

• Prevent ovulation by suppressing the release of gonadotropins (FSH, LH), thus inhibiting follicular development and preventing ovulation
• Progestogen negative feedback, decreases the pulse frequency of GnRH release by the hypothalamus, which decreases secretion of FSH and LH by the anterior pituitary. Decreased FSH inhibits follicular development, preventing an increase in estradiol levels. Progestogen negative feedback and the lack of estrogen positive feedback on LH secretion, prevents a mid-cycle LH surge. Inhibition of follicular development and the absence of a LH surge prevent ovulation
• Estrogen was originally included in OCP's for better cycle control, as it stabilizes the endometrium, thereby reducing the incidence of breakthrough bleeding. However, it was found that it also inhibits follicular development, and helps prevent ovulation. Estrogen negative feedback on the anterior pituitary, decreases the secretion of FSH, which inhibits follicular development, and helps prevent ovulation
• Progestogen also inhibits sperm penetration through the cervix into the upper genital tract (uterus and fallopian tubes), by decreasing the water content, and increasing the viscosity of the cervical mucus

Male oral contraceptives are currently not available commercially.

Female oral contraceptives include:

• Taken once per day:
  • Combined oral contraceptive pill, containing estrogen and progestin, including:
    • 1st generation, which are COCP's, containing >=50µg ethinyl estradiol
    • 2nd generation, which are COCP's containng <50µg ethinyl estradiol. Examples include with norethisterone (Norimin), with levonorgestrel (Microgynon, Alesse), with norethisterone (Tri-Cyclen)
    • 3rd generation, which are COCP's containing desogestrel, gestodene, or norgestimate
    • 4th generation, which are COCP's containing drospirenone (Yaz, Yasmin), dienogest, or nomegestrol acetate
  • Progestin-only pill, which use progestogen alone with doses taken continuously and no gaps between packs. Patients may experience irregular light bleeds, and whilst irregular in the 1st few months of taking, usually setles ot a regular pattern in time. The various types include:
    • Norethisterone (Micronor)
    • Etynodiol diacetate
    • Levonorgestrel
    • Desogestrel
    • Lynestrenol
• Emergency contraception pills (morning after pills), taken at the time of intercourse, or within a few days afterwards, including:
  • Yuzpe regimen, using combined oral contraceptives
  • Ulipristal acetate, an antiprogestogen

• Inhibit female fertility, if started within 5 days of the beginning of the menstrual cycle. If started any other time in the menstrual cycle, they provide contraception only after 7 consecutive days using the active pills → backup method of contraception is required
• Pills are just as effective whether taken continuous for prolonged periods of time, or if just initiated
• Non-contraceptive use, including:
  • PCOS
  • Endometriosis
  • Amenorrhea
  • Menstrual cramps
  • Adenomyosis
  • Menorrhagia (excessive menstruation)
  • Menstruation-related anemia
  • PID
  • Dysmenorrhea (painful menstruation)
  • Premenstrual syndrome
  • Irregular menstruation, to induce menstruation on a regular cycle, although it actually suppresses normal menstrual cycle, and then mimics a regular 28-day monthly cycle
  • Female athlete triad, causing menstrual dysfunction, to create menstrual bleeding cycles. However, the underlying cause is energy deficiency, and should be Tx by correcting the imbalance between calories eaten and burned by exercise
  • Mild to moderate acne

• Pre-existing CVD
• Familial tendency to form blood clots (e.g. familial factor V Leiden)
• Severe obesity
• Hypercholesterolemia
• Smokers >35yo
• Liver tumors
• Hepatic adenoma
• Severe cirrhosis of the liver
• Migraine w/ aura
• Known or suspected breast cancer

• COCP should be taken orally at the same time each day. If forgotten for more than 12 hours, protection will be reduced
  • For the 28-pill packs, one is taken each day for the 28 day cycle, where the last week of pills is placebo/sugar pills. They may contain iron supplement, as iron requirements increase during menstruation
  • For the 21-pill packs, one is taken each day for 3 weeks, following by 1 week of no pills
• If pills have been missed:
  • If 1 is missed [or started a new pack 1 day late], take the last pill missed now, even if this means taking 2 pills in one day. Then, carry on taking the rest of the pack as normal. No extra contraception is required
  • If 2+ pills are missed [or started a new pack 2+ days late], take the last pill missed now, even if this means taking 2 pills in one day. Leave any earlier missed pills. Carry on taking the rest of the pack as normal. Use extra contraception (e.g. condoms) for the next 7 days
  • If there has been unprotected sex in the previous 7 days and 2+ pills are missing in the first week of a pack, emergency contraception may be necessary, including either:
    • Morning after pill (aka emergency contraceptive pill), including ulipristal acetate which has to be taken within 3 days of sex, or levonorgestrel which has to be taken within 5 days of sex, both of which prevent or delay ovulation
    • IUD, which can be inserted into the uterus up to 5 days after unprotected sex, or up to 5 days after the earliest time the Pt could have ovulated. It may stop an egg from being fertilized or implanting in the Pt's womb
• Whilst on the COCP, withdrawal bleed will occur during the placebo week, but will still protect from pregnancy during this week

• Mistakes of the user, including:
  • Forgetting to take the pill one day (especially an active pill)
  • Not going to the pharmacy on time to renew the prescription
  • Decreased intestinal absorption of the active pill due to vomiting or diarrhea
  • Drug interactions of the active pill, by:
    • Decreasing contraceptive estrogen or progestogen levels, including:
      • Rifampicin
      • Barbiturates
      • Phenytoin
      • Carbamazepine
    • Impair bacterial flora, including:
      • Ampicillin
      • Doxycycline
• Mistake of those providing instructions, including information regarding:
  • Frequency of intake
• Conscious non-compliance with instructions

• Unintended pregnancy, the probability of pregnancy during the 1st year of "typical" use is 9%, contrasted with 0.3% for "perfect" use
• Spotting, especially during the first few months of use → breakthrough bleeding
• Irregular periods, especially during the first few months of use
• Reductions in menstrual flow, and even amenorrhea
• Leukorrhea (increased vaginal secretions)
• Mastalgia (breast tenderness)
• Increased blinking (32% more)
• In older, high-dose COCP's (not seen in current low-dise formulations):
  • Nausea, vomiting
  • Increased BP
  • Melasma (facial skin discoloration)
• Headache
• Bloating
• Swelling of the ankles/feet, weight gain → fluid retention
• Positive side effects, include improving conditions

• It does NOT protect against STD's → use condoms
• Increased risk of:
  • CVD risk, including:
    • HTN
    • Ischemic stroke
    • DVT
    • PE
  • Breast cancer, which dissapears 7 years after use has stopped
  • Cervical cancer, in those affected w/ HPV
  • Liver cancer
  • Gallstones → excess estrogen increases cholesterol in bile, decreases gallbaldder movement
  • There is insufficiently strong evidence it causes:
    • Weight gain
    • Depression (especially relating to progestin-only contraceptives)
• Decreased risk of:
  • Ovarian cancer
  • Endometrial cancer
  • Colorectal cancer
  • Anemia

• Used by more than 100 million women worldwide
• Use varies depending on country, age, education, and marital status
• 50% of new time users to end the pill before the end of the 1st year, due to breakthrough bleeding or amenorrhea

• Birth control (information regarding prescribing to minors)