Tadalafil MCQs With Answer

Tadalafil MCQs With Answer provides B.Pharm students a focused review of tadalafil’s pharmacology, clinical uses, and safety. This set emphasizes key topics: tadalafil as a PDE5 inhibitor, mechanism of action, pharmacokinetics (absorption, half-life ~17.5 hours, CYP3A4 metabolism), dosing strategies for ED, BPH and PAH, adverse effects (headache, back pain, dyspepsia), and important drug interactions (nitrates, alpha-blockers, CYP3A4 inhibitors). Questions target patient counseling, monitoring, contraindications, and formulation differences versus other PDE5 inhibitors. Designed for exam preparation and clinical pharmacy practice, the resource blends depth with clarity for efficient learning. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What is the primary mechanism of action of tadalafil?

• Selective inhibition of phosphodiesterase type 5 (PDE5)
• Stimulation of guanylate cyclase
• Inhibition of nitric oxide synthase
• Blockade of alpha-adrenergic receptors

Correct Answer: Selective inhibition of phosphodiesterase type 5 (PDE5)

Q2. Which clinical indications are officially associated with tadalafil?

• Erectile dysfunction, benign prostatic hyperplasia, and pulmonary arterial hypertension
• Hypertension and diabetes mellitus
• Asthma and chronic obstructive pulmonary disease
• Depression and anxiety disorders

Correct Answer: Erectile dysfunction, benign prostatic hyperplasia, and pulmonary arterial hypertension

Q3. What are common brand names for tadalafil formulations?

• Cialis and Adcirca
• Viagra and Revatio
• Levitra and Staxyn
• Proscar and Flomax

Correct Answer: Cialis and Adcirca

Q4. Approximately how long after oral dosing does tadalafil typically begin to take effect?

• About 30 minutes
• Less than 5 minutes
• More than 24 hours
• After 12 hours

Correct Answer: About 30 minutes

Q5. What is the commonly cited duration of tadalafil’s pharmacologic effect following a single dose?

• Up to 36 hours
• 4–6 hours
• 8–10 hours
• Less than 2 hours

Correct Answer: Up to 36 hours

Q6. Which enzyme system is primarily responsible for tadalafil metabolism?

• CYP3A4
• CYP2D6
• UDP-glucuronosyltransferase (UGT1A1)
• CYP1A2

Correct Answer: CYP3A4

Q7. What is the approximate elimination half-life of tadalafil in healthy adults?

• About 17.5 hours
• 2–4 hours
• 48–72 hours
• 30–60 minutes

Correct Answer: About 17.5 hours

Q8. Which medication class is absolutely contraindicated with tadalafil due to risk of severe hypotension?

• Nitrates
• Beta-blockers
• ACE inhibitors
• Calcium channel blockers

Correct Answer: Nitrates

Q9. Co-administration of tadalafil with which of the following requires caution because of additive hypotensive effects?

• Alpha-adrenergic blockers (alpha-blockers)
• Antacids
• Antihistamines
• Topical corticosteroids

Correct Answer: Alpha-adrenergic blockers (alpha-blockers)

Q10. How does a high-fat meal affect tadalafil absorption?

• Absorption is not significantly affected by food
• High-fat meal dramatically reduces absorption
• Food increases bioavailability fivefold
• Must be taken only on empty stomach for effect

Correct Answer: Absorption is not significantly affected by food

Q11. What is the approximate plasma protein binding of tadalafil?

• About 94% bound to plasma proteins
• Less than 10% bound
• Approximately 50% bound
• Fully unbound in plasma

Correct Answer: About 94% bound to plasma proteins

Q12. Inhibition of which secondary phosphodiesterase isoenzyme by tadalafil is associated with musculoskeletal adverse effects like myalgia and back pain?

• PDE11
• PDE2
• PDE4
• PDE7

Correct Answer: PDE11

Q13. What is a typical initial as-needed dosing recommendation for tadalafil in erectile dysfunction for most patients?

• 10 mg taken prior to anticipated sexual activity
• 100 mg taken daily
• 0.5 mg intravenously
• 50 mg once weekly

Correct Answer: 10 mg taken prior to anticipated sexual activity

Q14. Tadalafil is primarily metabolized to inactive metabolites and eliminated via which routes?

• Feces and urine after hepatic metabolism
• Exhaled air unchanged
• Only breast milk excretion
• Predominantly biliary excretion of parent drug without metabolism

Correct Answer: Feces and urine after hepatic metabolism

Q15. What counseling point should be emphasized regarding erections and tadalafil use?

• Seek emergency care if an erection lasts longer than 4 hours (risk of priapism)
• It is safe to use multiple doses within one hour if needed
• Tadalafil prevents sexually transmitted infections
• Discontinue sexual activity if erection occurs

Correct Answer: Seek emergency care if an erection lasts longer than 4 hours (risk of priapism)

Q16. Which adverse effect is most frequently reported with tadalafil therapy?

• Headache
• Severe neutropenia
• Renal failure
• Hyperglycemia

Correct Answer: Headache

Q17. Which vasodilator used for pulmonary hypertension is contraindicated with tadalafil due to risk of hypotension and syncope?

• Riociguat
• Sildenafil
• Prostaglandin E1 analogs
• Endothelin receptor antagonists

Correct Answer: Riociguat

Q18. Is tadalafil recommended for use in pregnant or breastfeeding women?

• No, tadalafil is not recommended in pregnancy or lactation due to lack of established safety
• Yes, it is first-line therapy in pregnancy
• Only recommended in breastfeeding women, not during pregnancy
• Recommended as vitamin supplement during pregnancy

Correct Answer: No, tadalafil is not recommended in pregnancy or lactation due to lack of established safety

Q19. Tadalafil increases levels of which intracellular mediator to promote smooth muscle relaxation in the corpus cavernosum?

• cGMP (cyclic guanosine monophosphate)
• cAMP (cyclic adenosine monophosphate)
• IP3 (inositol trisphosphate)
• Calcium ions

Correct Answer: cGMP (cyclic guanosine monophosphate)

Q20. Compared with sildenafil, a key clinical advantage of tadalafil is:

• Longer duration of action allowing once-daily or as-needed dosing up to 36 hours
• Faster onset in under one minute
• Complete lack of drug interactions
• Renal elimination without hepatic metabolism

Correct Answer: Longer duration of action allowing once-daily or as-needed dosing up to 36 hours

Q21. Which laboratory or clinical event should prompt immediate evaluation in a patient taking tadalafil?

• Sudden loss of vision in one or both eyes (possible NAION)
• Slight fatigue after exercise
• Temporary mild hiccups
• Seasonal allergy symptoms

Correct Answer: Sudden loss of vision in one or both eyes (possible NAION)

Q22. How should tadalafil dosing be adjusted when coadministered with strong CYP3A4 inhibitors?

• Reduce dose or avoid use due to increased tadalafil exposure
• No adjustment is necessary
• Double the dose because metabolism is increased
• Switch to an intravenous formulation

Correct Answer: Reduce dose or avoid use due to increased tadalafil exposure

Q23. Which patient population requires special consideration and possible dose adjustment when prescribing tadalafil?

• Patients with severe renal or hepatic impairment
• Healthy young adults under 30 with no comorbidities
• Patients who are avid marathon runners only
• Patients with seasonal allergies

Correct Answer: Patients with severe renal or hepatic impairment

Q24. Which effect is NOT commonly associated with tadalafil therapy?

• Significant neutropenia
• Flushing
• Nasal congestion
• Dyspepsia

Correct Answer: Significant neutropenia

Q25. For benign prostatic hyperplasia (BPH) symptom management, tadalafil is typically used as:

• Once-daily low-dose therapy (e.g., 5 mg)
• Intravenous bolus before surgery
• Topical cream applied to the scrotum
• Weekly intramuscular injection

Correct Answer: Once-daily low-dose therapy (e.g., 5 mg)

Q26. Which statement about tadalafil pharmacokinetics is TRUE?

• Tadalafil has high oral bioavailability and a long half-life supporting once-daily dosing options
• Tadalafil is minimally absorbed and requires parenteral administration
• Tadalafil is excreted entirely unchanged in urine
• Tadalafil immediately converts to active metabolites that prolong effect indefinitely

Correct Answer: Tadalafil has high oral bioavailability and a long half-life supporting once-daily dosing options

Q27. Which monitoring parameter is particularly relevant when a patient on tadalafil begins an alpha-blocker?

• Blood pressure for symptomatic hypotension
• Serum potassium for hyperkalemia
• Complete blood count for anemia
• Thyroid function tests for hypothyroidism

Correct Answer: Blood pressure for symptomatic hypotension

Q28. What is the recommended action if a patient on tadalafil experiences priapism lasting more than 4 hours?

• Seek emergency medical treatment immediately to prevent permanent tissue damage
• Wait at least 24 hours and reassess
• Take another dose of tadalafil to relieve the condition
• Apply local heat and ignore it

Correct Answer: Seek emergency medical treatment immediately to prevent permanent tissue damage

Q29. Which pharmacologic property explains why tadalafil may cause back pain in some patients?

• Partial inhibition of PDE11 in skeletal muscle leading to myalgia/back pain
• Direct nephrotoxic effect on kidney tissue
• Inhibition of acetylcholinesterase in neuromuscular junctions
• Excessive thyroid hormone release

Correct Answer: Partial inhibition of PDE11 in skeletal muscle leading to myalgia/back pain

Q30. As a B.Pharm student counseling a patient, which point about tadalafil safety should you emphasize?

• Avoid nitrates and report any sudden visual or hearing changes; seek immediate care for erections >4 hours
• It cures sexually transmitted infections
• It can be safely combined with any erectile agent for greater effect
• There is no need to inform other healthcare providers when taking tadalafil

Correct Answer: Avoid nitrates and report any sudden visual or hearing changes; seek immediate care for erections >4 hours

G S Sachin

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.

Mail- Sachin@pharmacyfreak.com