Review of Pharmacology - 9E (2015)

Review of Pharmacology
Cardiovascular System
200
66. Ans. (a) Pregnancy induced hypertension (Ref: Katzung 11/e p173)
‘Methyl-dopa was widely used in past but is now used primarily for hypertension in pregnancy
67. Ans. (d) Nifedipine (Ref: Katzung 10/e p175; KDT 6/e p543)
Nifedipine, amlodipine like calcium channel blockers can be used for hypertension.
68. Ans. (d) Atenolol (Ref: CMDT-2014/429)
• Beta blockers are no longer considered to be the first line antihypertensive agents. According to JNC-8, ACE inhibitors,
calcium channel blockers and diuretics are first line agents.
69. Ans. (d) Prazosin (Ref: CMDT-2010/409)
• Prazosin should be avoided as first choice because of risk of postural hypotension.
70. Ans. (c) Prazosin completely antagonizes its action (Ref: KDT 6/e p546)
• Clonidine is an a 2
agonist that acts by decreasing the central sympathetic outflow.
• Sedation, dry mouth and rebound hypertension are the principal adverse effects associated with clonidine.
• Prazosin is an a 1
selective blocker, therefore it is not able to block a 2
mediated actions.
71. Ans. (d) Nifedipine (Ref: Katzung 10/e p145, 179; KDT 11/e p185)
Nifedipine can be used rarely for the rapid control of blood pressure but the route of administration is sub-lingual. Fenoldopam
is a D 1
agonist used i.v. for hypertensive emergencies whereas urapidil is an α blocker. Enalaprilat (not enalparil)
can also be used for the same indication.
72. Ans. (b) Stimulation of guanylate cyclase (Ref: KDT 6/e p549)
Sodium nitroprusside acts by releasing nitric oxide (NO). This stimulates guanylate cyclase and results in the elevation of
cGMP, which is a potent vasodilator.
73. Ans. (a) Sodium nitroprusside (Ref: KDT 11/e p185)
It is the first choice drug for hypertensive emergencies.
74. Ans. (b) Beta blockers (Ref: KK Sharma 2007/619; KDT 6/e p139)
75. Ans. (b) ACE-inhibitors (Ref: KDT 5/e p450; KDT 6/e p484)
• ACE inhibitors and ARBs have fetopathic potential, therefore are contra-indicated in pregnancy.
76. Ans. (b) It causes dilation of both arteries and veins (Ref: KDT 6/e p540, 547, 548)
Hydralazine is a predominantly arteriolar dilator that relaxes blood vessels by releasing NO and opening K + channels.
There is compensatory increase in plasma renin activity with all vasodilators. Postural hypotension is predominanty
caused by dilatation of veins and is not a significant feature of hydralazine.
77. Ans. (b) Increase in LDL cholesterol on prolonged use (Ref: KDT 6/e p546)
Clonidine is a selective α 2
agonist that acts by decreasing central sympathetic outflow. Vasodilators can result in reflex
increase in renin release. This can be prevented by combining vasodilators with clonidine or b-blockers. Sedation and
dry mouth are prominent adverse effects of clonidine and a-methyldopa. These drugs decrease LDL and increase HDLcholesterol.
78. Ans. (a) Continued till the day of operation (Ref: CMDT 2014/47)
Before surgery, antihypertensive drugs should be continued till the day of surgery.
79. Ans. (b) Verapamil (Ref: KDT 6/e p484, 541, 544)
Thiazides and beta blockers should be avoided in diabetes mellitus whereas ACE inhibitors should not be given to a
patient with bilateral renal artery stenosis. Therefore, CCBs like verapamil are best agents to manage hypertension in
such a patient.
80. Ans. (a) Losartan; (b) Captopril; (c) Amlodipine (Ref: KDT 6/e p551)
• ACE inhibitors (e.g. captopril) and AT 1
antagonists (e.g. losartan) are first choice antihypertensive drugs for diabetic
patients.
• Calcium channel blockers (like amlodipine) and a-blockers (like prazosin) are also safe in diabetics.
• Thiazides and b-blockers should be avoided in diabetes mellitus.
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