PTCB Pharmacology #2 2 — Questions and Answers
Question 1: Which drug suffix is characteristic of calcium channel blockers (dihydropyridine class)?
- -olol
- -statin
- -pril
- -dipine (Correct answer)
Correct answer: -dipine
Dihydropyridine calcium channel blockers end in "-dipine" (amlodipine, nifedipine, felodipine). Non-dihydropyridines (verapamil, diltiazem) have different suffixes.
Question 2: Albuterol (ProAir, Ventolin) primarily acts on which receptor?
- Beta-1 adrenergic
- Alpha-1 adrenergic
- Muscarinic
- Beta-2 adrenergic (Correct answer)
Correct answer: Beta-2 adrenergic
Albuterol is a selective beta-2 adrenergic agonist that causes bronchodilation by relaxing airway smooth muscle. It is the most common rescue inhaler for asthma and COPD.
Question 3: Which term describes a drug that binds to a receptor and produces a response?
- Antagonist
- Inhibitor
- Agonist (Correct answer)
- Partial antagonist
Correct answer: Agonist
An agonist binds to a receptor and activates it to produce a pharmacological response. An antagonist binds but does not activate the receptor, blocking agonist effects.
Question 4: Loop diuretics like furosemide primarily cause loss of which electrolyte?
- Sodium only
- Calcium
- Potassium and sodium (Correct answer)
- Potassium only
Correct answer: Potassium and sodium
Loop diuretics cause loss of sodium, chloride, potassium, magnesium, and calcium. Hypokalemia is the most clinically significant electrolyte disturbance, requiring monitoring and supplementation.
Question 5: Which class of antibiotic inhibits cell wall synthesis by binding to penicillin-binding proteins (PBPs)?
- Aminoglycosides
- Fluoroquinolones
- Tetracyclines
- Beta-lactams (Correct answer)
Correct answer: Beta-lactams
Beta-lactam antibiotics (penicillins, cephalosporins, carbapenems) inhibit bacterial cell wall synthesis by binding to and inactivating penicillin-binding proteins (PBPs).
Question 6: What is the term for the concentration of a drug at which 50% of the maximum response is achieved?
- LD50
- MIC
- ED50 (EC50) (Correct answer)
- TD50
Correct answer: ED50 (EC50)
EC50 (or ED50) is the drug concentration (or dose) producing 50% of maximal effect on the dose-response curve. LD50 = lethal dose in 50% of animals; TD50 = toxic dose in 50%.
PTCB Pharmacology #2 2
Which drug suffix is characteristic of calcium channel blockers (dihydropyridine class)?