Q- Which one of the following regional anesthetics can cause methemoglobinemia if given in a large dose?
A-Bupivacaine
B-Cocaine
C-Prilocaine
D-Procaine
C-Prilocaine- Prilocaine is the most commonly associated local anesthetic with methemoglobinemia, especially when used in high doses. This occurs due to its metabolite, o-toluidine, which oxidizes hemoglobin to methemoglobin, reducing oxygen transport.
Q- Which of the following is the mechanism of antimicrobial action of cephalosporins?
A-Binding to the 30S Ribosomal Subunit
B-Inhibition of beta-lactamase
C-Inhibition of transpeptidation reactions
D-Interference with the synthesis of ergosterol
C-Inhibition of transpeptidation reactions- Cephalosporins are β-lactam antibiotics that work by inhibiting bacterial cell wall synthesis. They achieve this by binding to penicillin-binding proteins (PBPs) on bacterial cell walls. They inhibit transpeptidation of peptidoglycan strands, which is crucial for cell wall stability leading to bacterial cell lysis due to weakened structural integrity.
Q- Which one of the following medications is a non-selective beta receptor agonist?
A-Dobutamine
B-Isoproterenol
C-Norepinephrine
D-Terbutaline
B-Isoproterenol- It stimulates both β1 and β2 adrenergic receptors. β1 activation Increases heart rate (positive chronotropic effect) and cardiac contractility (positive inotropic effect). β2 activation causes vasodilation and bronchodilation.
