Week 4: Reproductive Pharmacology: Contraceptive Agents Flashcards
Ethinyl estradiol found in?
- Oral contraceptives
- transdermal patch
- contraceptive ring
Ethinyl estradiol MOA
Estrogens act by negative feedback at the level of the anterior pituitary and hypothalamus inhibiting FSH and LH secretion
Ethinyl estradiol Clinical uses
Contraceptiive agent (multiple routes of administration)
Ethinyl estradiol minor side effects
- Nausea
- edema
- headache
- worsening migraines
- breakthrough bleeding
- increased skin pigmentation
- increased incidence of vaginal infections
- amenorrhea
Ethinyl estradiol Major side effects
- Venous thromboembolism (3x incidence cf. women not taking oral contraceptives)
- Hypertension
- Lipid effects (↑TG, ↑cholesterol, ↑ or no change in HDL, ↓ LDL)
Ethinyl estradiol contraindications
CV risks are greatest in smokers > 35 years old
Ethinyl estradiol drug interactions
Multiple pharmokinetic interactions involving CYP and uridine 5’-diphosphate glucuronosyl transferase (UGT) catalyzed reactions
Progestins found in?
- eg norethindrone or norgestrel in oral contraceptives
- Norelgestromin in transdermal patch
- etonogestrel used in contraceptive ring and subcutaneous implant
- Medroxyprogesterone acetate given as IM depot
- Levonorgestrel used in IUD and given orally for emergency contraception
- administered in combination with ethinyl estradiol or alone
Progestins MOA
- inhibit ovulation
- progestogen negative feedback decreases the pulse frequency of GnRH release by the hypothalamus which decreases the secretion of FSH and LH by the anterior pituitary
- decreased levels of FSH inhibit follicular development
- secondary action: progestins promote secretion of thick cervical mucus which acts as a barrier and inhibits sperm movement past the cervix
Progestins clinical use
Contraceptive agent (multiple routes of administration)
Progestins side effects
- Breakthrough bleeding is the most common adverse effect (up to 25% of patients)
- May increase acne
- headache
Progestins contraindications
No evidence of increased VTE for oral forms
injectable forms (depo forms) may be contraindicated in women with a history of VTE
Ulipristal acetate MOA
- acts as a progesterone receptor agonist/antagonist
- it delays/inhibits ovulation
- may reduce LH release
- may have a direct inhibitory effect on follicular rupture
- may exert effects on endometrium that reduce implantation
Ulipristal acetate clinical use
emergency contraception
Ulipristal acetate side effects
- Self-limited headache
- abdominal pain
- dizziness
- onset of menses earlier or later than expected by a few days
