Contraceptives Flashcards
The first type of Hormonal Contraceptives are Oral. what are the advantages and disadvantages of oral contraceptives?
Ease of use and efficacy
Disadvantage: inconsistent use may increase failure rate
Combined oral contraceptives contain estrogen and progestin. What are the estrogens and progestins?
Estrogens: Ethinyl Estradiol which is active or Mestranol which is converted in the liver to Ethinyl Estradiol
Progestins: Norethindrone, Norgestrel, Levonorgestrel, Desogesttrel, Norgestimate and Drospirenone
Almost all currently available progestins have some androgen activity. Some adverse effects of oral contraceptives are due to the androgenic activity of the progestin. Progestins vary in their androgenic activity..
Levonorgestrel and Norgestrel: highest androgenic activity
Norethindrone: has lower androgenic activity
Desogestrel and Norgestimate: even lower androgen activity
Drospirenone: has antiandrogenic activity
Combined oral contraceptives are available in monophasic, biphasic and triphasic preparations. What does this mean?
Monophasic: fixed doses of estrogen and progestin in each active pill
Biphasic (Not used often) and Triphasic: Contain varying proportions of one or both hormones during the pill cycle
Why were biphasic and triphasic preparations introduced?
Reduce the amount and total monthly dose of progestins as well as mimic more closely the hormonal changes of the menstrual cycle
–no evidence that bi or tri are superior to mono in prevention of pregnancy
The combined oral contraceptives most commonly used today are what?
Low Dose
—contain 35ug of ethinyl estradiol or less
This reduced dose of estrogen and progestin has decreased adverse effects and risks associated with oral contraceptive used. However, they are more likely to result in contraceptive failure if doses are missed
Continuous combination regimens provide hormone containing pills for 21 days, then?
very low dose estrogen and progestin for an additional 4-7 days
Combination oral contraceptives work primarily before fertilization to prevent conception, by preventing ovulation. How does this occur?
They suppress LH and FSH release and ovulation does not occur
–additionally progestin thickens cervical mucus thus preventing sperm penetration, and induces changes in the endometrium that make implantation of the embryo unlikely.
If the patient starts the combined oral contraceptive on day one of her menstrual cycle what happens?
She will be protected from pregnancy immediately
If she starts the combined oral contraceptive on the fifth day of her period or before, what happens?
She will be protected from pregnancy immediately, unless she has a short menstrual cycle (23 days or less) in which case she will need backup contraception until she has taken the pill for seven days
If the patient starts combined oral contraceptive on any other day of her cycle what will happen?
she will not be protected from pregnancy immediately, and will need backup contraception until she has taken the pill for seven days
In addition to preventing pregnancy, there are several non contraceptive benefits associated with the use of combined oral contraceptive pills, those are?
Reduction in the risk of endometrial cancer
Reduction in the risk of ovarian cancer
Improved regulation of menstruation
Relief of benign breast disease
Prevention of ovarian cysts
Reduction in the risk of symptomatic pelvic inflammatory disease
Improvement of acne control
Next lets go through some adverse effects of oral contraceptives.
- Breakthrough bleeding: most common and is more of a problem with lower doses of estrogen
- Headache: mild and transient ; have been reports of increased frequency of cerebrovascular accidents
- Insulin Resistance: progestins compete with insulin for binding to its receptor, use of current oral contraceptives, which have a low dose progestin dose rarely cause hyperglycemia
- Hirsutism: acne, oily skin are androgenic properties
- Melasma: secondary to estrogen stimulation of melanocyte production
- Amenorrhea
- Dyslipidemia: no effect
- Depression
- Carcinogenicity: decrease endometrial and ovarian cancer
CVS adverse effects are the major adverse effects of birth control, they are rare but serious, what are these effects?
Thromboembolism, Thrombophlebitis, Hypertension, increased incidence of MI and cerebral and coronary thrombosis
- -most common among women who smoke and who are older than 35
- -estrogen increase hepatic production of factor VII, factor X and fibrinogen
Moving on to drug interactions. Explain the effect of Rifampin use on oral contraceptives?
Reduces efficacy by inducing hepatic P450 enzymes and thus increasing the metabolism of estrogen
–use of a backup nonhormonal contraceptive method during the course of rifampin is recommended
What are the other P450 inducers known to cause increased metabolism of combined oral contraceptives?
Carbamazepine, oxcarbazepine, phenytoin, phenobarbital, primidone, topiramate, vigabatrin and St. John’s Wart
What are the absolute contraindications of oral contraceptives?
Pregnancy Thrombophlebitis or thromboembolic disorders Stroke or coronary artery disease Cancer of the breast Abnormal vaginal bleeding Estrogen dependent cancer Benign or malignant tumor of the liver Uncontrolled HTN Diabetes mellitus with vascular disease Age over 35 and smoking greater than 15 cigarettes a day Thrombophilia Migraine with aura Active hepatitis Surgery or orthopedic injury requiring prolonged immobilization
What are the relative contraindications of oral contraceptives ?
Migraine without Aura Hypertension Heart or kidney disease Diabetes Mellitus Gallbladder Disease Cholestasis during pregnancy Sickle cell disease Lactation
Now or women unable to take estrogen containing oral contraceptives, there is an alternative – progestin only contraceptives. What are some features of this type of contraceptives?
Progestin Only (Minipills)
- –contain norethindrone or norgestrel
- -less effectives than combined oral contraceptives
- -have no shown the risk of thromboembolic events as products containing estrogen have.
- -decreased dysmenorrhea, decreased menstrual blood loss and decreased premenstrual syndrome symptoms
Progestin only pills are highly efficacious but block ovulation in only 60 to 80% of cycles, so what contributes to their effectiveness?
Thickening of cervical mucus, which decreases sperm production, and to endometrial alterations that impair implantation
What are some non oral hormonal contraceptives?
Transdermal – patch —- contains ethinyl estradiol and progestin
Transvaginal — ring — ethinyl estradiol and a progestin
Injectable Preparations — depo provera – progestin only that contains depot medroxyprogesterone acetate – given once every 3 months
What are some of the Side Effects of the Depo - Provera injection?
Cons:
menstrual irregularities and weight gain
significant loss of bone mineral density — a black box warning cautions against the risk of potentially irreversible bone mineral density loss associated with long term use.
on discontinuation, the return of fertility can be delayed by approx 10 to 12 months
What are the subdermal progestin implants and IUS?
Subdermal:
–contains progestin and is effective for 3 years and is placed under the skin
IUS:
Levonorgestrel reservoir and is effective for 5 years
What are some non hormonal contraceptive methods?
Barrier Contraceptives
—Condoms
—Diaphragms and Cervical Caps: used along with spermicides to prevent pregnancy
Spermicides: nonoxynol-8, destroys the cell membranes of sperm
Intrauterine Devices (IUDs): does not prevent ovulation
Sterilization: interruption of the fallopian tubes in women or the vas deferens in men
What methods of contraceptive are the most effective?
Oral Combined Contraceptive Pill: 99.9% ; 97%
Mirena: 99.9% ; 99.8%
Implanon: 99.95% ; 99.95%
Progestin Only: 99.5% ; 97%
What are the hormonal methods for emergency postcoital contraception?
Plan B and Next Choice
–levonorgestrel (first tablet within 73 hours of sex and the second 12 hours later)
Ella
–ulipristal acetate: selective progesterone receptor modulator that acts mainly as a progesterone antagonist to inhibit or delay ovulation
What is the non hormonal method for emergency postcoital contraception?
Copper IUD – within 5 days of sex
