PTCB Pharmacology #1 2 — Questions and Answers
Question 1: Which drug class do "-pril" suffix drugs belong to?
- ARBs
- Beta-blockers
- ACE inhibitors (Correct answer)
- Calcium channel blockers
Correct answer: ACE inhibitors
Drugs ending in "-pril" (lisinopril, enalapril, ramipril, benazepril) are ACE inhibitors that prevent conversion of angiotensin I to angiotensin II.
Question 2: What is the primary mechanism of proton pump inhibitors (PPIs)?
- Neutralize stomach acid
- Block histamine H2 receptors
- Irreversibly inhibit H+/K+ ATPase enzyme in parietal cells (Correct answer)
- Coat stomach mucosa
Correct answer: Irreversibly inhibit H+/K+ ATPase enzyme in parietal cells
PPIs irreversibly bind and inhibit the H+/K+ ATPase (proton pump) in gastric parietal cells, providing potent and long-lasting acid suppression of 80–95%.
Question 3: Thiazide diuretics like hydrochlorothiazide work primarily by:
- Inhibiting carbonic anhydrase in the proximal tubule
- Blocking aldosterone receptors in the collecting duct
- Inhibiting sodium reabsorption in the distal convoluted tubule (Correct answer)
- Blocking sodium-potassium-chloride cotransporter in the loop of Henle
Correct answer: Inhibiting sodium reabsorption in the distal convoluted tubule
Thiazide diuretics inhibit the NaCl cotransporter in the distal convoluted tubule, reducing sodium reabsorption. Loop diuretics (furosemide) block the Na-K-2Cl transporter in the thick ascending limb.
Question 4: Benzodiazepines exert their sedative effects by:
- Blocking NMDA glutamate receptors
- Enhancing GABA-A receptor activity by increasing chloride channel opening frequency (Correct answer)
- Inhibiting serotonin reuptake
- Activating mu-opioid receptors
Correct answer: Enhancing GABA-A receptor activity by increasing chloride channel opening frequency
Benzodiazepines bind to GABA-A receptors at a site distinct from GABA, enhancing the effect of GABA by increasing the frequency of chloride channel opening, producing sedation, anxiolysis, and muscle relaxation.
Question 5: Which of the following correctly describes pharmacokinetics?
- The study of drug mechanisms on the body
- What the body does to the drug: absorption, distribution, metabolism, excretion (Correct answer)
- The study of drug-receptor interactions
- The measure of drug toxicity at the cellular level
Correct answer: What the body does to the drug: absorption, distribution, metabolism, excretion
Pharmacokinetics (PK) describes what the body does to a drug: Absorption, Distribution, Metabolism, and Excretion (ADME). Pharmacodynamics (PD) describes what the drug does to the body.
Question 6: Which receptor do beta-blockers primarily block to reduce heart rate?
- Alpha-1 adrenergic receptors
- Muscarinic (M2) receptors
- Beta-1 adrenergic receptors (Correct answer)
- Beta-2 adrenergic receptors
Correct answer: Beta-1 adrenergic receptors
Beta-1 adrenergic receptors are predominant in the heart. Blocking these receptors reduces heart rate (negative chronotropy), contractility (negative inotropy), and blood pressure.
PTCB Pharmacology #1 2
Which drug class do "-pril" suffix drugs belong to?