This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Pharmacology
Nitroglycerine is used in Angina pectoris. The mechanism of action is primarily a 
Select and explain. 
A. Arteriolar dilator, B. Post capillary venodilator, C. Increase oxygen myocardial demand, D. Decrease myocardial work load
B: Post capillary venodilator
Answer: B: Post capillary venodilator 
Explanation: (Post capillary venodilator): (540 KDT 7th edition)NITRATES (GTN, Nitroglycerine)* Most prominent action is exerted on vascular smooth muscleNitrates dilate veins more than arteries|Peripheral pooling of blood|Decreased venous return (ie preload on heart is reduced)|End diastolic size and pressure are reduced|Decreased cardiac work* Nitroglycerine are used sublingually because terminates first pass metabolism* *** Nitroglycerine is effective when retained sublingually because it is non-ionic and has very high lipid solubility (22-Goodman)