B.Pharm. Bachelor of Pharmacy Bachelor of Pharmacy (B.Pharm.) 4 — Questions and Answers
Question 1: Which class of antibiotics works by inhibiting bacterial cell wall synthesis by blocking transpeptidation?
- Aminoglycosides
- Fluoroquinolones
- Beta-lactams (Correct answer)
- Macrolides
Correct answer: Beta-lactams
Beta-lactam antibiotics inhibit transpeptidases (penicillin-binding proteins), preventing cross-linking of peptidoglycan strands in the bacterial cell wall.
Question 2: A patient with renal impairment would require dose adjustment for which of the following drugs?
- Propranolol
- Diazepam
- Gentamicin (Correct answer)
- Haloperidol
Correct answer: Gentamicin
Gentamicin is primarily eliminated unchanged by the kidneys, so renal impairment leads to drug accumulation and nephrotoxicity or ototoxicity if not dose-adjusted.
Question 3: Which excipient in tablet formulation is classified as a disintegrant?
- Magnesium stearate
- Microcrystalline cellulose
- Croscarmellose sodium (Correct answer)
- Povidone
Correct answer: Croscarmellose sodium
Croscarmellose sodium is a superdisintegrant that swells rapidly upon contact with water, breaking tablets apart to release the drug for dissolution.
Question 4: Selective serotonin reuptake inhibitors (SSRIs) treat depression by:
- Inhibiting monoamine oxidase
- Blocking serotonin receptors postsynaptically
- Preventing reuptake of serotonin into the presynaptic neuron (Correct answer)
- Increasing serotonin synthesis
Correct answer: Preventing reuptake of serotonin into the presynaptic neuron
SSRIs block the serotonin transporter (SERT) on presynaptic neurons, preventing serotonin reuptake and increasing its availability in the synaptic cleft.
Question 5: Which process in drug metabolism typically converts lipophilic drugs to more polar metabolites for excretion?
- Phase I reactions only
- Phase II reactions only
- Both Phase I and Phase II reactions (Correct answer)
- Biliary excretion
Correct answer: Both Phase I and Phase II reactions
Phase I reactions (oxidation, reduction, hydrolysis) introduce functional groups, and Phase II reactions (conjugation) add large polar moieties, collectively increasing drug hydrophilicity for renal excretion.
Question 6: What is the primary purpose of the USP dissolution test for solid oral dosage forms?
- To assess tablet hardness and friability
- To measure the rate and extent of drug release from the dosage form (Correct answer)
- To determine drug stability under stress conditions
- To evaluate tablet appearance and color uniformity
Correct answer: To measure the rate and extent of drug release from the dosage form
The USP dissolution test measures the rate and extent of drug release from solid dosage forms, serving as an in vitro surrogate for in vivo drug absorption.
Question 7: A loop diuretic like furosemide exerts its effect by blocking which transporter in the kidney?
- Na+/K+-ATPase in collecting duct
- Na+-Cl- cotransporter in distal tubule
- Na+/K+/2Cl- cotransporter in thick ascending limb (Correct answer)
- Aquaporin-2 channels in collecting duct
Correct answer: Na+/K+/2Cl- cotransporter in thick ascending limb
Furosemide inhibits the Na+/K+/2Cl- cotransporter (NKCC2) in the thick ascending limb of the loop of Henle, preventing sodium and water reabsorption.
B.Pharm. Bachelor of Pharmacy Bachelor of Pharmacy (B.Pharm.) 4
Which class of antibiotics works by inhibiting bacterial cell wall synthesis by blocking transpeptidation?