Pharmacology of Reproduction – Contraception & Hormone Replacement

30 question-and-answer flashcards covering menstrual physiology, reproductive hormones, contraceptive pharmacology, hormone replacement therapy, contraindications, mechanisms, and emergency contraception.

What is the major secretory estrogen produced by the ovary?

Estradiol (E2, 17β-estradiol).

Which synthetic estrogen is most commonly used in combined oral contraceptives and at what daily dose range?

Ethinyl estradiol, typically 0.005–0.03 mg per day (5–30 µg).

How do estrogens exert their genomic effects inside target cells?

They dissociate from SHBG, enter the nucleus, bind estrogen receptors (ER-α or ER-β), and regulate gene transcription.

Give two cardiovascular or metabolic effects of physiological estrogens.

Maintain normal skin/vascular function and decrease bone resorption; also raise plasma triglycerides and increase coagulation factors II, VII, IX, X.

Name two key reproductive actions of progesterone during the menstrual cycle.

Triggers the pre-ovulatory LH surge and converts the proliferative endometrium to a secretory state after ovulation; also supports breast maturation and raises basal body temperature.

Define hypothalamic anovulation and cite one pharmacologic treatment.

Ovulation failure due to low GnRH/gonadotropins from stress, weight loss, exercise, drugs, etc.; treated with low-dose combined hormonal therapy or recombinant FSH for infertility.

Which hormone regimen is recommended for premature ovarian insufficiency (POI)?

Combined estrogen-progestin replacement (often low-dose combined oral contraceptive).

List three long-term medical treatments used in polycystic ovary syndrome (PCOS).

Lifestyle modification; progestin or combined oral contraceptives to reduce androgen excess/endometrial risk; ovulation induction with clomiphene, letrozole, or recombinant FSH.

What is the main medical strategy for symptom control in endometriosis?

Suppression of ovulation with continuous progestin/combined contraceptives or GnRH agonists (plus surgery when indicated).

What are the primary goals of menopausal hormone replacement therapy (HRT)?

Relieve vasomotor symptoms and genitourinary syndrome of menopause and help preserve bone density.

Provide one example of an oral estrogen used in HRT and its usual dose.

17β-Estradiol 2 mg daily (e.g., Estrofem, Zumenon).

What are the two major pharmacologic classes of hormonal contraceptives?

Estrogen-progestin (combined) contraceptives and progestin-only contraceptives.

Describe the principal mechanism of action of combined oral contraceptives (COCs).

They suppress GnRH, thereby inhibiting LH and FSH release, preventing the mid-cycle LH surge and ovulation; progestin also thickens cervical mucus, alters endometrium, and reduces tubal motility.

What is a monophasic combined oral contraceptive regimen?

A fixed hormone dose for 21 days followed by 7 placebo days (or 24 hormone/4 placebo to shorten withdrawal bleeding).

Give three category 4 (absolute) contraindications to combined estrogen-progestin contraception.

(Any three) Age ≥ 35 plus ≥ 15 cigarettes/day; BP ≥ 160/100 mmHg; active VTE; ischemic heart disease or stroke history; migraine with aura; current breast cancer; severe liver disease.

Name two non-contraceptive health benefits of COCs.

Regulation of menstrual cycle disorders and reduction of endometrial/ovarian cancer risk (also relief of pelvic pain, fewer ovarian cysts, improved bone density).

State two common early side effects of combined hormonal contraceptives.

Nausea and breast tenderness (others: headache, unscheduled bleeding).

Give an example of a non-oral combined contraceptive formulation.

Etonogestrel/ethinyl estradiol vaginal ring delivering 0.120 mg/0.015 mg per day (NuvaRing).

List four forms of progestin-only contraception.

Low-dose oral pills (desogestrel 75 µg or drospirenone 4 mg), etonogestrel implant, levonorgestrel-releasing IUDs, and depot medroxyprogesterone acetate injections.

What are the three main mechanisms by which progestin-only methods prevent pregnancy?

Suppress ovulation, thicken cervical mucus to block sperm, and thin the endometrium to impair implantation.

Provide two advantages of progestin-only over combined contraceptives.

Suitable for women with VTE risk, hypertension, obesity, diabetes; safe during breastfeeding; fewer estrogenic side effects; fertility returns quickly after stopping (except DMPA).

Name two absolute contraindications to progestin-only contraception.

Known or suspected breast cancer; undiagnosed abnormal uterine bleeding (also severe active liver disease or tumors).

Which method is considered the most effective emergency contraception (EC)?

Insertion of a copper intrauterine device (IUD) within 5 days of unprotected intercourse.

What is the single-dose regimen for ulipristal acetate used in EC?

One oral dose of 30 mg taken within 120 hours (5 days) after unprotected sex.

How do levonorgestrel and ulipristal acetate act as emergency contraceptives?

They delay or inhibit ovulation and may interfere with sperm/ovum transport; ulipristal is a selective progesterone receptor modulator with stronger ovulation inhibition.

Name three GnRH agonists used to suppress gonadotropin release clinically.

Triptorelin, leuprolide, and goserelin.

What is the therapeutic role of recombinant FSH (e.g., follitropin)?

Induction of ovulation in women with anovulatory infertility (e.g., hypothalamic anovulation or PCOS).

Why do transdermal or vaginal estrogen preparations have fewer hepatic effects than oral ethinyl estradiol?

They bypass first-pass metabolism, reducing stimulation of hepatic synthesis of clotting factors and other proteins.

Which synthetic progestin has both antiandrogenic and antimineralocorticoid properties?

Drospirenone.

What type of agent is tibolone and on which receptors does it act?

A synthetic steroid used for HRT that acts as an agonist at estrogen, progesterone, and androgen receptors (dose 2.5 mg/day).