WBR0881

Author	[[PageAuthor::Rim Halaby, M.D. [1]]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pharmacology
Sub Category	SubCategory::Hematology
Prompt	[[Prompt::A new drug is being developed for the treatment of intermittent claudication. One of the main studied mechanisms of action of this drug is the inhibition of phosphodiesterase III leading to arterial vasodilation to improve blood flow to ischemic areas and decrease the symptoms of claudication. What would you expect drugs with a similar mechanism of action to have as added benefit?]]
Answer A	AnswerA::Slowing of atherosclerotic vessel changes
Answer A Explanation	AnswerAExp::
Answer B	AnswerB::Inhibition of platelet aggregation
Answer B Explanation	AnswerBExp::
Answer C	AnswerC::Conversion of plasminogen to plasmin
Answer C Explanation	AnswerCExp::
Answer D	AnswerD::Dulling of inflammatory response
Answer D Explanation	AnswerDExp::
Answer E	AnswerE::Curing erectile dysfunction
Answer E Explanation	AnswerEExp::
Right Answer	RightAnswer::B
Explanation	[[Explanation::Phosphodiesterase III (PDE3) inhibitors such as cilostazol and dipyridamole are potent vasodilators that can be used in the treatment on intermittent claudication. By inhibiting PDE3, cAMP accumulates leading to the activation of protein kinase A (PKA). PKA in turn leads to the inhibition of myosin light-chain kinase (MLCK) causing the vascular smooth muscle to relax. Another important effect of PDE3 inhibition and cAMP accumulation is the inhibition of platelet aggregation. PDE3 inhibitors have also been used clinically for TIA and stroke prevention and have been shown to be a potent antithrombotic agent when compared to aspirin or ADP receptor blockers. Learning objective: References: Educational Objective: References: ]]
Approved	Approved::No
Keyword	WBRKeyword::Dipyridamole, WBRKeyword::cilostazol, WBRKeyword::PDE3 inhibitors
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::