Repeated USMLE Questions- Pharmacology MCQs- 282

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Q- Which of the following is the effect of digoxin on a case of heart failure?

A- Decreased stroke volume and vagal activity

B- Increased stroke volume and cardiac output

C- Increased sympathetic tone and decreased vagal activity

D- Rapid conduction through AV node

B- Increased stroke volume and cardiac output- Digoxin effect on a failing heart includes also decreased sympathetic tone and increased vagal activity resulting in delayed conduction through AV node and inhibition of SA node.

 

Q- Which of the following is the mechanism of action of flumazenil in the treatment of lorazepam toxicity?

A- Competitive inhibition at benzodiazepine receptors

B- Inhibition of alpha adrenoceptors

C- Noncompetitive inhibition of benzodiazepine receptors

D- Stimulation of dopamine receptors

A- Competitive inhibition at benzodiazepine receptors- Flumazenil reverses the action of benzodiazepines on GABA receptors.

 

Q- Which of the following is the role of infliximab in the management of rheumatoid arthritis?

A- Inhibition of dihydrofolate reductase

B- It is a TNF-alpha receptor agonist

C- It is a TNF-alpha receptor antagonist

D- It neutralizes the activity of TNF-alpha by binding to soluble forms of it

D- It neutralizes the activity of TNF-alpha by binding to soluble forms of it- It prevents the effective binding of TNF-alpha with its receptors so, it is not direct receptor antagonist.

 

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