SNLE Pharmacology 2 — Questions and Answers
Question 1: What is the 'first-pass effect' in pharmacology?
- Significant drug metabolism by the liver before reaching systemic circulation after oral administration (Correct answer)
- The first dose being more effective than subsequent doses
- The first sign of drug toxicity
- The initial drug distribution phase
Correct answer: Significant drug metabolism by the liver before reaching systemic circulation after oral administration
After oral ingestion, drugs absorbed from the gut pass through the portal circulation to the liver where they may be extensively metabolized before reaching systemic circulation. This reduces bioavailability (e.g., nitrates, morphine, propranolol have high first-pass effect and require higher oral doses or alternative routes).
Question 2: A patient is prescribed warfarin. Which food significantly increases bleeding risk?
- Excessive consumption of cranberry juice (Correct answer)
- Vitamin K-rich foods
- High-protein foods
- Calcium-rich dairy products
Correct answer: Excessive consumption of cranberry juice
Cranberry juice contains compounds that inhibit CYP2C9, the enzyme that metabolizes warfarin, leading to increased warfarin levels and INR elevation. This significantly increases bleeding risk. Vitamin K-rich foods (green leafy vegetables) actually reduce warfarin's anticoagulant effect.
Question 3: What is the mechanism of action of beta-blocker medications?
- Block beta-adrenergic receptors, reducing heart rate, contractility, and blood pressure (Correct answer)
- Increase heart rate and contractility
- Dilate peripheral blood vessels only
- Block calcium channels in cardiac cells
Correct answer: Block beta-adrenergic receptors, reducing heart rate, contractility, and blood pressure
Beta-blockers competitively block beta-1 receptors in the heart (reducing heart rate and contractility) and beta-2 receptors in bronchi and blood vessels. They reduce cardiac oxygen demand and blood pressure. Used for hypertension, angina, heart failure, and dysrhythmias.
Question 4: A patient on gentamicin therapy requires monitoring of which parameters?
- Renal function (creatinine, BUN) and hearing (ototoxicity) (Correct answer)
- Liver enzymes only
- Blood glucose
- Coagulation studies
Correct answer: Renal function (creatinine, BUN) and hearing (ototoxicity)
Aminoglycosides (gentamicin, tobramycin, amikacin) are nephrotoxic (damage renal tubular cells) and ototoxic (damage cochlear and vestibular hair cells). Peak and trough drug levels, creatinine, BUN, urine output, and audiologic testing are required during therapy.
Question 5: What is the correct action when a patient reports a new rash after receiving a medication?
- Stop the medication, assess severity, notify the physician, and document the reaction as an allergy (Correct answer)
- Continue the medication and document the rash
- Reduce the dose and observe
- Apply topical steroid without reporting
Correct answer: Stop the medication, assess severity, notify the physician, and document the reaction as an allergy
A new rash after drug administration may represent an allergic reaction ranging from mild to anaphylactic. The drug should be held, severity assessed (mild urticaria vs. angioedema, bronchospasm, hypotension suggesting anaphylaxis), the physician notified, and the reaction documented as an allergy in the medical record.
Question 6: Which medication requires a daily weight to be taken and reported?
- Digoxin and diuretics (Correct answer)
- Antibiotics
- Antipsychotics
- Vitamin supplements
Correct answer: Digoxin and diuretics
Daily weight monitoring is essential for patients on digoxin (to detect fluid retention from heart failure) and diuretics (to monitor fluid balance — rapid weight gain indicates fluid retention; rapid loss indicates over-diuresis). A weight gain of >1 kg/day should be reported.
SNLE Pharmacology 2
What is the 'first-pass effect' in pharmacology?