Oral contraceptives: pharmacology and uses MCQs With Answer

Introduction:

This question bank on Oral contraceptives: pharmacology and uses is designed for M.Pharm students preparing for advanced pharmacology examinations and clinical practice. It focuses on mechanism of action, pharmacokinetics, different formulations, adverse effects, contraindications, drug interactions and non-contraceptive therapeutic uses. Questions emphasize clinically relevant details such as progestin profiles, estrogen-related risks, thromboembolism, metabolic effects, enzyme-mediated interactions and emergency contraception options. Use these MCQs to test critical reasoning, recall of specific drug properties and application of guidelines in patient scenarios. Explanations are omitted to mimic exam conditions; review primary texts and guidelines for detailed rationales.

Q1. Which mechanism is primary for combined oral contraceptives (COCs) to prevent ovulation?

• Direct inhibition of ovarian steroidogenesis
• Inhibition of gonadotropin-releasing hormone receptors in the pituitary
• Suppression of mid-cycle LH surge via negative feedback on hypothalamic-pituitary axis
• Induction of luteal phase endometrial atrophy

Correct Answer: Suppression of mid-cycle LH surge via negative feedback on hypothalamic-pituitary axis

Q2. Which progestin used in oral contraceptives has significant antimineralocorticoid activity and can reduce fluid retention?

• Levonorgestrel
• Desogestrel
• Drospirenone
• Norgestimate

Correct Answer: Drospirenone

Q3. Which pharmacokinetic property of ethinylestradiol contributes most to variable exposure and interactions?

• High renal clearance unchanged
• Extensive first-pass hepatic metabolism and enterohepatic recirculation
• Complete absorption with no metabolism
• Primary excretion via bile as unchanged drug

Correct Answer: Extensive first-pass hepatic metabolism and enterohepatic recirculation

Q4. Which enzyme induction by rifampicin most affects oral contraceptive efficacy?

• CYP2D6 induction
• CYP3A4 induction
• CYP1A2 inhibition
• UDP-glucuronosyltransferase inhibition

Correct Answer: CYP3A4 induction

Q5. Which adverse effect is most strongly associated with estrogen component of COCs?

• Acne exacerbation
• Venous thromboembolism due to increased hepatic synthesis of clotting factors
• Amenorrhea caused by endometrial atrophy
• Insomnia

Correct Answer: Venous thromboembolism due to increased hepatic synthesis of clotting factors

Q6. Which contraceptive pill formulation is preferred in breastfeeding women to minimize effects on milk supply?

• Combined oral contraceptive with ethinylestradiol and levonorgestrel
• Progestin-only pill (mini‑pill)
• High-dose estrogen oral contraceptive
• Transdermal estradiol patch

Correct Answer: Progestin-only pill (mini‑pill)

Q7. Which progestin is associated with higher risk of acne and androgenic effects due to strong androgen receptor agonism?

• Drospirenone
• Cyproterone acetate
• Levonorgestrel
• Dienogest

Correct Answer: Levonorgestrel

Q8. What is the primary mechanism by which progestin-only pills prevent pregnancy?

• Inhibition of ovulation in all cycles
• Thickening of cervical mucus and alteration of endometrium
• Blocking uterine tubal motility
• Increasing basal body temperature to prevent implantation

Correct Answer: Thickening of cervical mucus and alteration of endometrium

Q9. Which emergency contraceptive remains effective up to 120 hours after unprotected intercourse and acts as a selective progesterone receptor modulator?

• Levonorgestrel single dose
• Ulipristal acetate
• Yuzpe regimen (combined estrogen-progestin)
• Mifepristone low dose

Correct Answer: Ulipristal acetate

Q10. Which patient condition is an absolute contraindication to estrogen-containing oral contraceptives?

• Well-controlled hypertension
• History of deep vein thrombosis or pulmonary embolism
• Migraine without aura in a 25-year-old
• Smoking 5 cigarettes/day at age 28

Correct Answer: History of deep vein thrombosis or pulmonary embolism

Q11. Combined oral contraceptives can have beneficial effects in which gynecologic condition by suppressing ovulation and reducing ectopic tissue growth?

• Polycystic ovary syndrome with desire for fertility immediately
• Endometriosis to reduce pelvic pain and lesion progression
• Acute pelvic inflammatory disease requiring antibiotics
• Uterine fibroid acute torsion

Correct Answer: Endometriosis to reduce pelvic pain and lesion progression

Q12. Which pharmacodynamic effect explains why combined oral contraceptives may increase serum triglycerides?

• Estrogen-induced hepatic VLDL synthesis
• Progestin-mediated lipoprotein lipase activation
• Estrogen-induced inhibition of hepatic lipase only
• Direct intestinal absorption enhancement of fats

Correct Answer: Estrogen-induced hepatic VLDL synthesis

Q13. A woman on a COC develops breakthrough bleeding and missed pills are excluded. Which pharmacologic reason is most likely?

• Excessive estrogen leading to endometrial overgrowth
• Inadequate progestin effect causing endometrial instability
• Complete suppression of endometrium causing atrophy
• Interaction with proton pump inhibitors

Correct Answer: Inadequate progestin effect causing endometrial instability

Q14. Which oral contraceptive option has the best compliance advantage of once-weekly dosing rather than daily?

• Combined oral contraceptive pill
• Transdermal contraceptive patch
• Progestin-only oral pill
• Depot medroxyprogesterone (intramuscular) every 12 weeks

Correct Answer: Depot medroxyprogesterone (intramuscular) every 12 weeks

Q15. Which interaction reduces the efficacy of oral contraceptives and may warrant alternative or backup contraception?

• Co-administration with ibuprofen
• Coadministration with strong CYP3A4 inducers like carbamazepine, phenytoin or rifampicin
• Use with topical corticosteroids
• Co-administration with high-dose vitamin C

Correct Answer: Coadministration with strong CYP3A4 inducers like carbamazepine, phenytoin or rifampicin

Q16. Which metabolic effect is commonly observed with progestin-dominant contraceptives compared to estrogen-containing COCs?

• Improved HDL cholesterol levels
• Increased insulin resistance and possible adverse effects on glucose tolerance
• Marked reduction in LDL cholesterol
• Significant reduction in triglycerides

Correct Answer: Increased insulin resistance and possible adverse effects on glucose tolerance

Q17. Which oral progestin is associated with a higher risk of ovulation suppression when used as a progestin-only pill?

• Norethindrone
• Desogestrel
• Norgestrel
• Medroxyprogesterone acetate oral

Correct Answer: Desogestrel

Q18. Which statement about the Yuzpe regimen for emergency contraception is correct?

• It uses a single high dose of levonorgestrel only
• It combines estrogen and progestin in two doses within 72 hours and has more side effects than levonorgestrel-only regimens
• It is effective up to 120 hours and is preferred over ulipristal acetate
• It functions by inducing uterine contractions to expel the fertilized ovum

Correct Answer: It combines estrogen and progestin in two doses within 72 hours and has more side effects than levonorgestrel-only regimens

Q19. Which oral contraceptive choice is most appropriate for a woman with heavy menstrual bleeding (menorrhagia) seeking contraception?

• Non-hormonal barrier method
• Combined oral contraceptive with cyclic high-dose estrogen
• Levonorgestrel-releasing intrauterine system (IUS) — though not oral, provides superior menorrhagia control
• Progestin-only daily pill containing norethindrone with no effect on bleeding

Correct Answer: Levonorgestrel-releasing intrauterine system (IUS) — though not oral, provides superior menorrhagia control

Q20. Which laboratory change is most likely to be observed in women on combined estrogen-progestin oral contraceptives?

• Decreased synthesis of sex hormone-binding globulin (SHBG)
• Increased SHBG and decreased free testosterone levels
• Marked increase in free thyroid hormone levels due to displacement
• Significant decrease in hepatic albumin synthesis

Correct Answer: Increased SHBG and decreased free testosterone levels

Download