Levonorgestrel MCQs With Answer — This concise introduction is tailored for B. Pharm students studying levonorgestrel pharmacology, formulations, dosing, and clinical applications. Key concepts covered include mechanism of action (ovulation inhibition, cervical mucus alteration, endometrial effects), pharmacokinetics (absorption, CYP3A4 metabolism, half‑life, protein binding), emergency contraception dosing, LNG‑IUS function, adverse effects, drug interactions, contraindications, and counseling points such as efficacy in high BMI and lactation safety. These MCQs emphasize clinical pharmacology, formulation differences, monitoring, and patient counseling to prepare you for exams and practice. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which is the primary mechanism by which levonorgestrel emergency contraception prevents pregnancy?
- Prevents sperm capacitation
- Delays or inhibits ovulation
- Acts as a spermicide in the uterus
- Causes immediate implantation failure
Correct Answer: Delays or inhibits ovulation
Q2. What is the commonly recommended single oral dose of levonorgestrel for emergency contraception?
- 0.75 mg once
- 0.75 mg followed by 0.75 mg after 12 hours
- 1.5 mg single oral dose
- 3.0 mg single oral dose
Correct Answer: 1.5 mg single oral dose
Q3. Levonorgestrel is best described as which of the following chemically?
- An estrogen receptor agonist
- The active levorotatory enantiomer of norgestrel
- A natural progesterone molecule
- A racemic mixture of progestins
Correct Answer: The active levorotatory enantiomer of norgestrel
Q4. What is the typical elimination half‑life range of levonorgestrel in plasma?
- 1–3 hours
- 6–8 hours
- Approximately 24–32 hours
- Over 72 hours
Correct Answer: Approximately 24–32 hours
Q5. Which hepatic enzyme system primarily metabolizes levonorgestrel?
- CYP2D6
- CYP3A4
- CYP1A2
- Renal dehydrogenases (no CYP involvement)
Correct Answer: CYP3A4
Q6. Levonorgestrel in plasma is mainly bound to which proteins?
- Only albumin
- Only alpha-1 acid glycoprotein
- Sex hormone–binding globulin (SHBG) and albumin
- Globulins only
Correct Answer: Sex hormone–binding globulin (SHBG) and albumin
Q7. Approximately what is the initial daily release rate of levonorgestrel from a commonly used LNG‑IUS (e.g., Mirena)?
- 5 µg/day
- 20 µg/day
- 100 µg/day
- 500 µg/day
Correct Answer: 20 µg/day
Q8. What is the primary local contraceptive effect of the levonorgestrel intrauterine system (LNG‑IUS)?
- Systemic ovulation suppression only
- Profound local endometrial suppression and altered endometrial receptivity
- Increased sperm motility
- Release of spermicidal agents
Correct Answer: Profound local endometrial suppression and altered endometrial receptivity
Q9. Within how many hours after unprotected intercourse is levonorgestrel emergency contraception most effective?
- Within 24 hours only
- Within 72 hours (3 days)
- Only effective after 5 days
- Effectiveness is equal up to 10 days
Correct Answer: Within 72 hours (3 days)
Q10. Which concomitant medication is known to reduce levonorgestrel effectiveness by inducing hepatic metabolism?
- Rifampin
- Amoxicillin
- Metformin
- Loratadine
Correct Answer: Rifampin
Q11. What is the general recommendation regarding levonorgestrel emergency contraception use in breastfeeding women?
- Contraindicated during breastfeeding
- Considered safe during breastfeeding with minimal exposure in milk
- Must stop breastfeeding for 7 days after dose
- Requires milk expression and discard for 24 hours
Correct Answer: Considered safe during breastfeeding with minimal exposure in milk
Q12. Levonorgestrel exhibits which off‑target hormonal activity that may contribute to side effects?
- Strong estrogenic activity
- Antiandrogenic activity
- Moderate androgenic activity
- Thyroid receptor antagonism
Correct Answer: Moderate androgenic activity
Q13. Which condition is an absolute contraindication to inserting a levonorgestrel IUS?
- History of migraine without aura
- Current pregnancy
- Previous cesarean section
- Mild hypertension
Correct Answer: Current pregnancy
Q14. Which adverse effect is most commonly reported after taking oral levonorgestrel emergency contraception?
- Permanent infertility
- Irregular bleeding and spotting
- Severe liver failure
- Renal impairment
Correct Answer: Irregular bleeding and spotting
Q15. At the hypothalamic–pituitary level, levonorgestrel emergency contraception primarily prevents pregnancy by:
- Stimulating FSH release
- Inhibiting the LH surge required for ovulation
- Increasing prolactin secretion
- Blocking GnRH receptors permanently
Correct Answer: Inhibiting the LH surge required for ovulation
Q16. Which of the following formulations is levonorgestrel available in clinically?
- Oral emergency contraceptive tablets only
- Intrauterine system only
- Oral tablets, LNG‑IUS, and subdermal implants
- Transdermal patch only
Correct Answer: Oral tablets, LNG‑IUS, and subdermal implants
Q17. Compared to combined estrogen–progestin contraceptives, levonorgestrel‑only methods have which effect on venous thromboembolism (VTE) risk?
- Much higher VTE risk
- Similar VTE risk
- Lower VTE risk
- Guaranteed VTE prevention
Correct Answer: Lower VTE risk
Q18. How would you describe the oral bioavailability of levonorgestrel?
- Very low (<10%)
- Moderate (30–50%)
- High (>90%)
- Zero, it is not absorbed orally
Correct Answer: High (>90%)
Q19. If a patient vomits within 2 hours of taking levonorgestrel emergency contraception, what is the recommended action?
- No action needed; dose still effective
- Repeat the dose as soon as possible
- Switch to copper IUD only
- Prescribe broad‑spectrum antibiotics
Correct Answer: Repeat the dose as soon as possible
Q20. Access-wise, levonorgestrel emergency contraception is typically classified in many countries as:
- Prescription‑only medication everywhere
- Over‑the‑counter (OTC) availability in many countries
- Hospital inpatient use only
- Controlled opioid class
Correct Answer: Over‑the‑counter (OTC) availability in many countries
Q21. Levonorgestrel exerts its contraceptive effects primarily through binding to which receptor?
- Estrogen receptor
- Progesterone receptor
- Glucocorticoid receptor
- Insulin receptor
Correct Answer: Progesterone receptor
Q22. Which menstrual change may occur after taking levonorgestrel emergency contraception?
- No change in cycle timing is possible
- Immediate permanent amenorrhea
- Menstrual delay or temporary irregular bleeding
- Onset of ovulation within 24 hours
Correct Answer: Menstrual delay or temporary irregular bleeding
Q23. What routine laboratory monitoring is required for patients using levonorgestrel emergency contraception?
- Baseline liver function tests
- Complete blood count every month
- No routine laboratory monitoring required
- Coagulation profile every 3 months
Correct Answer: No routine laboratory monitoring required
Q24. Levonorgestrel emergency contraception is most effective when taken at which menstrual phase?
- After implantation has occurred
- During the luteal phase after ovulation only
- Before ovulation or before the LH surge
- On the day of expected menses only
Correct Answer: Before ovulation or before the LH surge
Q25. Relative to estrogenic effects, levonorgestrel demonstrates which activity profile?
- Strong estrogenic activity and no progestogenic effect
- Minimal estrogenic activity with primary progestogenic action
- Equal estrogenic and anti‑estrogenic activity
- Exclusive mineralocorticoid activity
Correct Answer: Minimal estrogenic activity with primary progestogenic action
Q26. Does levonorgestrel prevent pregnancy by reliably preventing implantation of a fertilized ovum?
- Yes, its primary action is to prevent implantation
- No, its primary action is preventing or delaying ovulation rather than implantation
- It dissolves the fertilized ovum directly
- It converts endometrium to bone tissue
Correct Answer: No, its primary action is preventing or delaying ovulation rather than implantation
Q27. How are levonorgestrel metabolites primarily eliminated from the body?
- Excreted unchanged in urine only
- Excreted as metabolites in urine and feces
- Exhaled via the lungs
- Stored permanently in adipose tissue
Correct Answer: Excreted as metabolites in urine and feces
Q28. Which therapeutic benefit is commonly achieved with levonorgestrel IUS placement beyond contraception?
- Worsening of heavy menstrual bleeding
- Reduction in menstrual blood loss and treatment of heavy menstrual bleeding
- Guaranteed cure of endometriosis
- Permanent sterility within 24 hours
Correct Answer: Reduction in menstrual blood loss and treatment of heavy menstrual bleeding
Q29. In case of suspected levonorgestrel overdose, what is the usual management?
- Administer naloxone immediately
- Perform hemodialysis emergently
- Provide symptomatic and supportive treatment
- Induce emesis and repeat dosing
Correct Answer: Provide symptomatic and supportive treatment
Q30. Which counseling point regarding levonorgestrel emergency contraception and body weight/BMI is important for patients?
- Efficacy is unchanged regardless of BMI
- May be less effective in women with high body mass index (BMI)
- Should be doubled automatically in obese patients
- BMI has no clinical relevance to hormonal contraception
Correct Answer: May be less effective in women with high body mass index (BMI)
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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