All Free Pharmacology MCQs with Answers

Every Pharmacology question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.

476 questions · page 4 of 24

  • A. 1% to 10%
  • B. 10% to 20%
  • C. 20% to 30
  • D. 30% to 40%

Explanation: Reported penicillin allergy varies widely among populations, commonly around 1% to 10%.

Correct answer: 1% to 10%
  • A. Inhibiting the binding of aminoacyl tRNA to the ribosomal complex
  • B. Inhibiting peptidyl transferase
  • C. Inactivating elongation factors
  • D. Causing misreading of mRNA

Explanation: Tetracyclines bind the bacterial 30S ribosomal subunit and block attachment of aminoacyl-tRNA to the acceptor site.

Correct answer: Inhibiting the binding of aminoacyl tRNA to the ribosomal complex
  • A. Piperacillin
  • B. Mezlocillin
  • C. Azlocillin
  • D. Flucloxacillin

Explanation: Piperacillin, mezlocillin and azlocillin are ureidopenicillins with extended Gram-negative activity.

Correct answer: Flucloxacillin
  • A. A long acting macrolide
  • B. Short action quinolone
  • C. Short acting macrolide
  • D. Long acting polypeptide

Explanation: Roxithromycin is a semisynthetic, long-acting macrolide related to erythromycin.

Correct answer: A long acting macrolide
  • A. Active against pseudomonas aeruginose
  • B. Inhibits Beta-lactamase
  • C. It is a ureido penicillin
  • D. Given parenterally

Explanation: Piperacillin is a ureidopenicillin active against organisms such as Pseudomonas and is administered parenterally.

Correct answer: Inhibits Beta-lactamase
  • A. Cephadroxil
  • B. Cefepime
  • C. Cefotaxime
  • D. Cefoperazone

Explanation: Cephadroxil is an oral first-generation cephalosporin. Cefotaxime and cefoperazone are third generation, while cefepime is fourth…

Correct answer: Cephadroxil
  • A. Sulphonamide
  • B. Carbamide
  • C. Cephalosporins
  • D. Ofloxacin

Explanation: Cephalosporins contain the beta-lactam ring and inhibit bacterial cell-wall synthesis.

Correct answer: Cephalosporins
  • A. Inhibition of bacterial protein synthesis by binding to subunit of bacterial ribosomes
  • B. Inhibition of cell wall peptidoglycan synthesis by competitive inhibition of transpetidases
  • C. Reduced drug causes strand breaks in DNA
  • D. Inhibition of DNA synthesis by inhibiting DNA-Dependent RNA polymerase

Explanation: Beta-lactams bind penicillin-binding proteins and competitively inhibit transpeptidases, preventing cross-linking of peptidoglycan in the…

Correct answer: Inhibition of cell wall peptidoglycan synthesis by competitive inhibition of transpetidases
  • A. Fungal
  • B. Viral
  • C. Bacterial
  • D. Rickettesial

Explanation: Amphotericin B is a polyene antifungal that binds ergosterol in fungal cell membranes and forms pores.

Correct answer: Fungal
  • A. Rifampicin
  • B. Vancomycin
  • C. Chloramphenicol
  • D. Tetracycline

Explanation: Rapid intravenous infusion of vancomycin can cause histamine release, producing flushing and erythema of the face and upper body known as…

Correct answer: Vancomycin
  • A. Enfuvirtide
  • B. Lamivudine
  • C. Efavirenz
  • D. Ritonavir

Explanation: Lamivudine inhibits reverse transcriptase in HIV and also suppresses hepatitis B virus polymerase, so it has activity against both…

Correct answer: Lamivudine
  • A. Intravenous Penicillin G
  • B. Antihistamines
  • C. Tetracyclines
  • D. Steroids

Explanation: The Jarisch-Herxheimer reaction is an acute inflammatory response after treatment of spirochetal infection, often causing fever, chills…

Correct answer: Antihistamines
  • A. is a broad spectrum antiprotozoal drug
  • B. Active against bacteroides and clostridium
  • C. An effective alternative for infection caused by aerobic gram positive cocci
  • D. May cause peripheral neuropathy on prolonged use

Explanation: Metronidazole is active against anaerobes such as Bacteroides and Clostridium and against several protozoa, but it does not effectively…

Correct answer: An effective alternative for infection caused by aerobic gram positive cocci
  • A. Red
  • B. Green
  • C. Yellow
  • D. Brown

Explanation: Tetracycline incorporated into developing teeth produces yellow staining and can show yellow fluorescence under ultraviolet light.

Correct answer: Yellow
  • A. Penicillin is inactivated by erythromycin
  • B. Erythromycin exerts its effects extracellularly
  • C. Erythromycin enhances the B-lactamases activity
  • D. Penicillin is only effective against growing cells

Explanation: Penicillins kill actively growing bacteria, whereas erythromycin is bacteriostatic and inhibits their growth, so the two effects can be…

Correct answer: Penicillin is only effective against growing cells
  • A. Enfuvirtide
  • B. Nelfinavir
  • C. Efavirenz
  • D. Etanercept:

Explanation: Enfuvirtide is a fusion inhibitor that binds HIV gp41 and prevents fusion of the viral envelope with the host-cell membrane.

Correct answer: Enfuvirtide
  • A. Metronidazole
  • B. Diloxanide furoate
  • C. Quinidochlor
  • D. Furazolidone

Explanation: Asymptomatic intestinal amoebic cyst carriage requires a luminal amoebicide, and diloxanide furoate is a standard effective choice.

Correct answer: Diloxanide furoate
  • A. Cefeperazone
  • B. Cefuroxime
  • C. Cefoxitin
  • D. Cefadroxil

Explanation: Cefoperazone is a third-generation cephalosporin; the option spells it "Cefeperazone." Cefuroxime is second generation, while cefoxitin…

Correct answer: Cefeperazone
  • A. Thiamine
  • B. Pyridoxine
  • C. Niacin
  • D. Riboflavin

Explanation: Isoniazid depletes pyridoxine, or vitamin B6, producing peripheral neuropathy and sometimes seizures.

Correct answer: Pyridoxine
  • A. Bacterial meningitis
  • B. Rickettsial infection
  • C. Syphilis
  • D. Anthrax

Explanation: Penicillin G is used for syphilis, susceptible meningitis, and anthrax, but it has no useful activity against rickettsiae.

Correct answer: Rickettsial infection