Contraceptives Flashcards
Goals of Contraception
- Most common goal = prevention of pregnancy
- Other goals:
- Menstrual cycle regulation
- Reduction of premenstrual symptoms
- Treatment of acne
which oral contraceptives have less side effects
Progesting-only oral contraceptives
- Norethindrone, Norgestrel
Combined oral contraceptives
- Contain a combination of an estrogen and a progestin
- The estrogen is either ethinyl estradiol or mestranol
- Mestranol is a prodrug that is converted to ethinyl estradiol
• Progestins include:
- Norethindrone
- Norgestrel
- Levonorgestrel
- Desogestrel
- Norgestimate
- Drospirenone
• Progestins vary in their androgenic activity (highest to lowest):
• Levonorgestrel and norgestrel: highest • Norethindrone: lower • Third-generation progestins, such as desogestrel and norgestimate: even lower • Drospirenone: antiandrogenic
Combination contraceptives MOA
• Combination oral contraceptives work primarily before
fertilization to prevent conception
• They act by preventing ovulation
• They suppress LH and FSH release and ovulation does
not occur
• Additionally, the progestin thickens cervical mucus thus
preventing sperm penetration, and induces changes in the
endometrium that impair implantation
Benefits of combined oral contraceptives
• Reduction on 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 in acne control
combined oral contraceptives AE
• Concerns about cardiovascular toxicity initially limited the long-term use of these drugs
• The decrease in estrogen and progestin content has led
to a reduction in adverse effects
• Concerns about cardiovascular toxicity initially limited the long-term use of these drugs
Insulin Resistance
• Progestins may cause insulin resistance by competing
with insulin for its receptor
- Hirsutism (androgenic progestins)
- Melasma (melanocyte stimulation by estrogen)
Cardiovascular Disorders
• Estrogens increase production of factor VII, factor X and
fibrinogen, therefore increasing the risk of thromboembolic events
• The risk is increase by obesity, smoking, hypertension and diabetes
combined oral contraceptives
DI:
Liver Enzyme Induction
• Rifampin induces hepatic P450 enzymes and increases
metabolism of estrogen
• Use of a backup nonhormonal contraceptive method
during the course of rifampin therapy is recommended
Types of combined oral contraceptives:
• Continuous combination regimens
- how do they work
provide hormone containing pills for 21 days, then very-low-dose estrogen and progestin for an additional 4-7 days
Types of combined oral contraceptives:
• Extended-cycle formulations
- how do they work
• Extended-cycle formulations increase the number of
hormone-containing pills to 84 days, followed by a 7-day
placebo phase
• This results in four menstrual cycles per year
- good for painful mensturatioon
Types of combined oral contraceptives:
• Most of the formulations available have 21 hormonally
active pills
21 hormonally
active pills followed by 7 placebo pills to allow withdrawal
from bleeding
• This facilitates consistent daily pill intake
•Most common adverse effect of oral contraceptives?
Cause?
Breakthrough Bleeding
• It is more of a problem with lower doses of estrogen
because estrogen stabilizes the endometrium
AE Oral contraceptives: Cardiovascular Disorders - how often does this happen? - what other AE accompany this? - common in which age group?
• Although rare, the most serious adverse effect of oral
contraceptives is cardiovascular disease
• This includes thromboembolism, thrombophlebitis,
hypertension, MI, cerebral and coronary thrombosis
• These adverse effects are most common among women
who smoke and who are older than 35 years
Oral contraceptives decrease or increase carcinogenicity (ENDOMETRIAL OR OVARIAN CANCER)?
DECREASE!
