Home/Quiz/Pharmacology MCQs : General Pharmacology, CNS Drugs & Antimicrobial Agents Pharmacology MCQs : General Pharmacology, CNS Drugs & Antimicrobial Agents Welcome to your Pharmacology MCQs : General Pharmacology, CNS Drugs & Antimicrobial Agents 1. A patient receives an oral drug that undergoes extensive first-pass metabolism in the liver. Compared with an equivalent intravenous dose, what happens to its bioavailability? It is reduced It is increased to 100% It is unchanged in every patient It becomes independent of dose It is determined only by renal clearance None Hint 2. A drug produces the same maximal therapeutic effect as another drug but requires a lower dose to achieve a given response. Which property is greater? Potency Efficacy Toxicity only Half-life only Clearance None Hint 3. A patient receives a drug that binds a receptor and prevents an agonist from producing its effect. Increasing the agonist concentration overcomes the inhibition. What type of antagonist is this? Competitive antagonist Irreversible antagonist Physiologic antagonist Chemical antagonist Partial agonist only None Hint 4. A patient is treated with a drug that produces a submaximal response even when all available receptors are occupied. What is this drug? Partial agonist Full agonist Competitive antagonist Inverse agonist only Enzyme inhibitor with no receptor action None Hint 5. A patient taking a drug with a narrow therapeutic index develops toxicity after a small dose increase. What does a narrow therapeutic index imply? Therapeutic and toxic concentrations are relatively close The drug has no adverse effects The drug is never metabolized The drug is always ineffective orally The drug cannot cross membranes None Hint 6. A drug has a plasma half-life of 8 hours and is administered repeatedly at a fixed interval. Approximately when is near steady-state concentration generally reached? After about 4–5 half-lives After one half-life After 10 minutes Immediately after the first dose Only after 20 half-lives None Hint 7. A patient with severe renal impairment receives a drug that is primarily eliminated unchanged by the kidneys. What adjustment is commonly required? Reduce the dose or extend the dosing interval Always double the dose Increase the dosing frequency Stop all hepatic metabolism Increase the loading dose indefinitely None Hint 8. A drug is extensively protein bound in plasma. Another medication displaces it from albumin, transiently increasing its free fraction. Which fraction is pharmacologically active? Free unbound drug Albumin-bound drug only Metabolized drug only Renal filtrate only Drug stored in bone only None Hint 9. A patient receives an intravenous loading dose of a drug with a very large volume of distribution. Which property does the large volume of distribution suggest? Extensive distribution into tissues Complete confinement to plasma Exclusive renal elimination No tissue binding Zero lipid solubility None Hint 10. A patient taking a prodrug requires hepatic metabolism to produce its active metabolite. Which process is responsible for conversion of the parent compound? Drug metabolism Glomerular filtration only Receptor downregulation Protein synthesis by ribosomes Passive diffusion only None Hint 11. A patient develops severe toxicity after repeated dosing of a drug because its clearance is markedly reduced. Which pharmacokinetic parameter has most directly changed? Clearance Bioavailability only Volume of distribution only Receptor affinity Efficacy None Hint 12. A drug follows first-order elimination. Which statement best describes this process? A constant fraction is eliminated per unit time A constant amount is eliminated per unit time Elimination is independent of concentration The drug cannot be metabolized Only renal secretion is possible None Hint 13. A patient overdoses on a drug that follows capacity-limited elimination at high concentrations. Which pharmacokinetic feature may occur? Zero-order elimination over part of the concentration range Complete absence of metabolism Infinite clearance Instantaneous renal excretion No change in half-life None Hint 14. A drug has a high hepatic extraction ratio and is given intravenously. Which factor has a major influence on its hepatic clearance? Hepatic blood flow Urinary pH only Plasma calcium only Gastric emptying only Bone mineral density None Hint 15. A patient develops a drug reaction that is predictable, dose-related, and related to the known pharmacologic action of the medication. How is this adverse effect classified? Type A adverse drug reaction Type B adverse drug reaction Idiosyncratic allergy only Withdrawal reaction Placebo reaction None Hint 16. A patient develops an unpredictable severe reaction to a drug that is not related to its usual pharmacologic effect. Which classification best fits? Type B adverse drug reaction Type A adverse drug reaction Therapeutic effect Dose adjustment Drug tolerance None Hint 17. A patient taking a receptor agonist chronically requires progressively larger doses to obtain the same response. What phenomenon has developed? Tolerance Idiosyncrasy Hypersensitivity First-pass effect Bioavailability None Hint 18. A patient abruptly stops long-term treatment with a centrally acting drug and develops symptoms related to rebound overactivity. What process is occurring? Withdrawal First-pass metabolism Therapeutic drug monitoring Loading Bioavailability enhancement None Hint 19. A patient has a genetic enzyme variant that causes unusually slow metabolism of a medication, resulting in increased plasma concentration at standard doses. Which concept explains this? Pharmacogenetic variation Receptor desensitization Tachyphylaxis First-pass effect Placebo effect None Hint 20. A patient receives a drug by intravenous bolus. Which pharmacokinetic process occurs first before the drug can distribute to tissues? Direct entry into systemic circulation Gastrointestinal absorption First-pass hepatic metabolism Intestinal degradation Biliary excretion None Hint 21. A patient with generalized tonic-clonic seizures is started on a medication that increases the frequency of GABA-A receptor chloride-channel opening. Which drug is most consistent with this mechanism? Benzodiazepine Fluoxetine Haloperidol Levodopa Lithium None Hint 22. A patient with status epilepticus requires an intravenous medication for rapid seizure termination. Which drug is commonly used initially? Lorazepam Fluoxetine Haloperidol Donepezil Levodopa None Hint 23. A patient with epilepsy is treated with a drug that blocks voltage-gated sodium channels and is associated with gingival hyperplasia. Which drug is most likely? Phenytoin Valproate Ethosuximide Gabapentin Levetiracetam None Hint 24. A child has absence seizures characterized by brief episodes of staring with a 3-Hz spike-and-wave EEG pattern. Which drug is classically effective? Ethosuximide Phenytoin Carbamazepine Diazepam only Levodopa None Hint 25. A patient with bipolar disorder develops manic episodes and is treated with a mood stabilizer that can cause nephrogenic diabetes insipidus. Which drug is most likely? Lithium Fluoxetine Haloperidol Carbamazepine only Buspirone None Hint 26. A patient with major depressive disorder is started on an SSRI. Which adverse effect is particularly associated with this drug class? Sexual dysfunction Severe gingival hyperplasia Marked nephrotoxicity in all patients Irreversible hearing loss Bronchospasm in every patient None Hint 27. A patient taking an SSRI is prescribed a monoamine oxidase inhibitor without an adequate washout period and develops agitation, hyperthermia, and clonus. Which syndrome is most likely? Serotonin syndrome Neuroleptic malignant syndrome Malignant hyperthermia Cholinergic crisis Anticholinergic syndrome None Hint 28. A patient treated with a typical antipsychotic develops rigidity, tremor, and bradykinesia. Which adverse effect is most likely? Extrapyramidal symptoms Nephrogenic diabetes insipidus Ototoxicity Peptic ulcer disease Hypoglycemia None Hint 29. A patient taking an antipsychotic develops fever, severe muscle rigidity, altered mental status, and markedly elevated creatine kinase. Which syndrome is most likely? Neuroleptic malignant syndrome Serotonin syndrome Lithium toxicity Cholinergic crisis Opioid withdrawal None Hint 30. A patient with Parkinson disease has bradykinesia and rigidity. Which drug is converted in the brain to dopamine and is usually combined with a peripheral decarboxylase inhibitor? Levodopa Haloperidol Fluoxetine Donepezil Phenytoin None Hint 31. A patient receiving levodopa develops nausea and orthostatic hypotension. Which strategy reduces peripheral conversion of levodopa? Add carbidopa Add haloperidol Add phenytoin Add atropine Add fluoxetine None Hint 32. A patient with Alzheimer disease is prescribed a drug that inhibits acetylcholinesterase and modestly improves cognitive symptoms. Which drug is most likely? Donepezil Levodopa Haloperidol Phenytoin Diazepam None Hint 33. A patient with neuropathic pain is treated with a drug that binds the alpha-2-delta subunit of voltage-gated calcium channels. Which drug is most likely? Gabapentin Haloperidol Fluoxetine Levodopa Ethosuximide None Hint 34. A patient receives morphine after surgery and develops respiratory depression and pinpoint pupils. Which receptor mediates most of these effects? Mu-opioid receptor Dopamine D2 receptor GABA-B receptor NMDA receptor only Muscarinic M3 receptor None Hint 35. A patient with opioid overdose is unconscious with respiratory depression and miosis. Which antidote should be administered? Naloxone Flumazenil Atropine Physostigmine Protamine None Hint 36. A patient with generalized anxiety disorder needs a non-benzodiazepine medication that enhances serotonin 5-HT1A signaling and has delayed onset. Which drug is most likely? Buspirone Diazepam Haloperidol Lithium Phenobarbital None Hint 37. A patient taking a benzodiazepine for several months wants to stop abruptly. Why should withdrawal be considered? Abrupt discontinuation can cause anxiety, insomnia, and seizures It always causes severe hypoglycemia It causes permanent hypertension in all patients It causes iron deficiency It prevents GABA synthesis permanently None Hint 38. A patient with Parkinson disease develops dyskinesias and hallucinations after prolonged dopaminergic therapy. Which class of medication may be used to reduce motor complications by stimulating dopamine receptors? Dopamine agonists D2 antagonists Muscarinic antagonists only SSRIs Opioid antagonists None Hint 39. A patient with major depressive disorder is started on an SNRI. Which neurotransmitters are primarily increased in the synaptic cleft? Serotonin and norepinephrine Dopamine and GABA only Acetylcholine and glutamate only Histamine and glycine Endorphins only None Hint 40. A patient with insomnia is prescribed a short-acting benzodiazepine-like drug that acts at the GABA-A receptor. Which drug is most likely? Zolpidem Fluoxetine Lithium Haloperidol Levodopa None Hint 41. A patient with bacterial pneumonia is prescribed a beta-lactam antibiotic. What is the primary antimicrobial action of penicillins? Inhibition of bacterial cell-wall peptidoglycan cross-linking Inhibition of human ribosomal protein synthesis Blockade of viral reverse transcriptase Inhibition of fungal ergosterol synthesis Inhibition of folate absorption in humans None Hint 42. A patient with severe immediate hypersensitivity to penicillin requires treatment for a bacterial infection. Which concern is most important when selecting another beta-lactam? Potential cross-reactivity with certain beta-lactams Guaranteed cross-reactivity with every antibiotic Immediate renal failure from all cephalosporins Universal ototoxicity Loss of all antibacterial activity None Hint 43. A patient receives vancomycin for a serious infection caused by resistant gram-positive organisms. What bacterial structure does vancomycin primarily target? Cell-wall peptidoglycan precursor 30S ribosomal subunit DNA gyrase RNA polymerase Folate reductase None Hint 44. A hospitalized patient develops a serious gram-negative infection and is treated with an aminoglycoside. Which mechanism explains its antibacterial effect? Irreversible inhibition of the 30S ribosomal subunit Inhibition of cell-wall transpeptidation Inhibition of fungal ergosterol Blockade of viral DNA polymerase Inhibition of folate synthesis at DHFR only None Hint 45. A patient treated with gentamicin develops rising serum creatinine and hearing difficulty. Which adverse effects are classically associated with aminoglycosides? Nephrotoxicity and ototoxicity Severe hypoglycemia and rash only Aplastic anemia only Pulmonary fibrosis only Hyperthyroidism None Hint 46. A patient with atypical pneumonia is prescribed azithromycin. Which bacterial target is inhibited by macrolides? 50S ribosomal subunit 30S ribosomal subunit DNA gyrase Dihydrofolate reductase Cell membrane sterols None Hint 47. A patient taking a macrolide develops palpitations and QT prolongation. Which adverse effect is relevant to this antibiotic class? QT interval prolongation Severe nephrogenic diabetes insipidus Gingival hyperplasia Permanent bone marrow aplasia in all patients Severe hyperkalemia None Hint 48. A patient with a serious MRSA infection receives linezolid. Which adverse effect becomes important during prolonged therapy? Myelosuppression Gingival hyperplasia Nephrogenic diabetes insipidus Hyperthyroidism Cataracts in every patient None Hint 49. A patient with tuberculosis is started on rifampin. Which characteristic is important when counseling the patient? Orange-red discoloration of body fluids Severe gingival hyperplasia Permanent hearing loss in every patient Marked hypoglycemia Nephrotic syndrome in all patients None Hint 50. A patient with tuberculosis develops peripheral neuropathy during isoniazid therapy. Which supplement helps prevent this complication? Pyridoxine (vitamin B6) Vitamin C Vitamin K Vitamin D Folic acid only None Hint 51. A patient receiving ethambutol for tuberculosis develops difficulty distinguishing red from green. Which toxicity is suspected? Optic neuritis Ototoxicity Nephrotoxicity Hepatic failure only Peripheral neuropathy from B6 deficiency None Hint 52. A patient with tuberculosis develops hyperuricemia and joint pain during therapy with pyrazinamide. Which adverse effect is most characteristic? Hyperuricemia Optic neuritis Red-orange body fluids Severe QT prolongation only Gray baby syndrome None Hint 53. A patient with a urinary tract infection is treated with trimethoprim-sulfamethoxazole. Which metabolic pathway is targeted sequentially by these drugs? Bacterial folate synthesis Bacterial cell-wall synthesis Fungal ergosterol synthesis Viral protease synthesis Human cholesterol synthesis None Hint 54. A patient receiving trimethoprim develops elevated serum creatinine without a comparable decline in true glomerular filtration. What can explain this finding? Reduced tubular secretion of creatinine Direct destruction of all glomeruli Increased creatinine production from muscle Complete renal artery obstruction Increased erythropoietin release None Hint 55. A patient with a serious anaerobic infection receives metronidazole. Which adverse effect is classically associated with this drug? A disulfiram-like reaction with alcohol Permanent deafness in all patients Gingival hyperplasia Severe hypocalcemia Nephrogenic diabetes insipidus None Hint 56. A patient receives a fluoroquinolone for a susceptible bacterial infection. Which bacterial enzyme is inhibited? DNA gyrase and topoisomerase IV Dihydrofolate reductase only 50S ribosome Peptidoglycan transpeptidase RNA polymerase only None Hint 57. A teenager taking a fluoroquinolone develops severe tendon pain. Which adverse effect is classically associated with this drug class? Tendinopathy and tendon rupture Gingival hyperplasia Nephrogenic diabetes insipidus Aplastic anemia in all patients Permanent red-green color blindness None Hint 58. A patient with severe infection receives chloramphenicol. Which serious hematologic adverse effect is associated with this drug? Aplastic anemia Polycythemia Thrombocytosis Sickle-cell crisis Iron overload None Hint 59. A neonate treated with chloramphenicol develops abdominal distension, cyanosis, and cardiovascular collapse. Which syndrome is most likely? Gray baby syndrome Red man syndrome Serotonin syndrome Neuroleptic malignant syndrome Reye syndrome None Hint 60. A patient with Clostridioides difficile-associated diarrhea is treated with an oral drug that remains largely within the intestinal lumen. Which drug is commonly used for initial therapy? Vancomycin Gentamicin Rifampin Isoniazid Acyclovir None Hint 61. A patient with herpes simplex infection is treated with acyclovir. Which viral enzyme is important for selective activation of the drug? Viral thymidine kinase Viral neuraminidase Bacterial beta-lactamase Human carbonic anhydrase Fungal catalase None Hint 62. A patient with influenza receives oseltamivir early in the illness. Which viral protein is inhibited? Neuraminidase Reverse transcriptase Integrase Protease only DNA gyrase None Hint 63. A patient with HIV is treated with a drug that inhibits reverse transcriptase after phosphorylation inside infected cells. Which class is this? Nucleoside reverse transcriptase inhibitor Protease inhibitor Integrase inhibitor Neuraminidase inhibitor Beta-lactam antibiotic None Hint 64. A patient with HIV is treated with a drug that prevents integration of viral DNA into the host genome. Which class is being used? Integrase inhibitor Macrolide NRTI Protease inhibitor Sulfonamide None Hint 65. A patient develops oral candidiasis after prolonged broad-spectrum antibiotic use. Which antifungal targets ergosterol synthesis by inhibiting fungal CYP-dependent enzymes? Azole Echinocandin Amphotericin B Flucytosine Terbinafine only None Hint 66. A patient with invasive fungal infection receives amphotericin B. Which mechanism explains its antifungal action? Binding ergosterol and forming membrane pores Inhibiting bacterial cell-wall transpeptidase Blocking viral neuraminidase Inhibiting human ribosomes Blocking folate synthesis None Hint 67. A patient develops fever, chills, and hypotension during an infusion of amphotericin B. Which adverse effect is characteristic? Infusion-related reactions Gingival hyperplasia Tendon rupture Red-green color blindness Gray baby syndrome None Hint 68. A patient with a serious infection caused by resistant gram-positive cocci receives daptomycin. Why is daptomycin not used for pneumonia? Pulmonary surfactant inactivates it It cannot enter the bloodstream It is only active against fungi It is destroyed by gastric acid It inhibits human alveolar cells directly None Hint 69. A patient with severe infection is treated with tetracycline. Which ribosomal subunit is inhibited? 30S 50S 60S 80S 70S mitochondrial only None Hint 70. A child receives tetracycline during tooth development. Which adverse effect is a major concern? Permanent tooth discoloration and impaired bone growth Aplastic anemia in all patients Severe optic neuritis Orange urine Gray baby syndrome None Hint 71. A patient with an infection caused by an anaerobic organism receives clindamycin. Which serious complication should be considered? Clostridioides difficile colitis Optic neuritis Nephrogenic diabetes insipidus Tendon rupture Hyperthyroidism None Hint 72. A patient with a urinary tract infection caused by a susceptible gram-negative organism is treated with a drug that inhibits bacterial folate synthesis by competing with PABA. Which drug is most likely? Sulfamethoxazole Vancomycin Acyclovir Azithromycin Gentamicin None Hint 73. A patient with bacterial meningitis receives ceftriaxone. Which property makes ceftriaxone useful in this setting? Good penetration into cerebrospinal fluid during meningeal inflammation Complete absence of protein binding Exclusive activity against fungi Inhibition of viral reverse transcriptase No renal or biliary elimination None Hint 1 out of 37 Time's up
