Review of Pharmacology - 9E (2015)

Review of Pharmacology
59. Ans. (b) Glimepiride; (d) Rosiglitazone; (e) Repaglinide (Ref: KDT 6/e p269-270;CMDT 2010/1092)
• Metformin (a biguanide) being excreted unchanged by kidneys is contraindicated in renal failure. Its excretion
is impaired in renal failure resulting in raised plasma level. It can block hepatic uptake of lactate to provoke
lactic acidosis. Renal failure affects not only lactate removal by kidneys but also metformin excretion.
• Glimepride (All sulfonylurease except chlorpropamide) is completely metabolized by the liver to relatively
inactive metabolic products.
• Repaglinide undergoes complete metabolism in liver to inactive biliary products. It is useful in patients with
renal impairment or elderly.
• Rosiglitazone is primarily metabolized by CYP. It is less likely to cause hepatotoxicity than troglitazone. It is
contraindicated in liver disease and CHF.
Endocrinology
60. Ans. (b) Hypoglycemia (Ref: KDT 6/e p262)
61. Ans. (b) Glipizide (Ref: KDT 6/e p266)
62. Ans. (a) Acarbose (Ref: KDT 6/e p270)
• It is an alpha-glucosidase inhibitor.
• It inhibits the breakdown of complex carbohydrates to simple carbohydrates and thus decreases their absorption.
63. Ans. (c) An old man with severe bradycardia and hypotension resulting from ingestion of overdose of atenolol
(Ref: KDT 6/e p274)
• Glucagon is the antidote of β-blocker poisoning. It acts by increasing cAMP in the heart via stimulation of glucagon
receptors. Cyclic AMP stimulates the heart.
• Calcium gluconate can also be used for the treatment of β-blocker poisoning.
64. Ans. (b) Enzymatic receptor (Ref: KDT 6/e p258)
Insulin acts by stimulation of tyrosine kinase receptors.
65. Ans. (b) Subcutaneous (Ref: KDT 6/e p259)
66. Ans. (b) Rapidly absorbed (Ref: KDT 6/e p261)
Human insulin has rapid absorption and shorter duration of action than pork or beef insulin.
67. Ans. (a) Is more potent (Ref: KDT 6/e p266)
Second generation (like glipizide) sulfonylureas are more potent than first generation agents (like chlorpropamide).
• Chlorpropamide is the longest acting sulfonylurea.
• Sulfonylureas can cause hypoglycemia (even in non-diabetics) due to release of insulin.
68. Ans. (b) It is less liable to cause lactic acidosis (Ref: KDT 6/e p269)
Incidence of lactic acidosis is more with phenformin and that of megaloblastic anemia (due to interference with vitamin B 12
absorption) is more with metformin.
69. Ans. (b) Type 1 diabetics (Ref: KDT 6/e p266)
• Sulfonylureas decrease blood glucose in diabetics as well as non-diabetics.
• It requires at least 30% of functional beta cells for their action.
• Insulin is the only treatment for type 1 diabetes.
70. Ans. (d) All of the above (Ref: KDT 6/e p267)
71. Ans. (a) Non-diabetics (Ref: KDT 6/e p269)
• Metformin is the drug of choice for the treatment of obese diabetic patients, as it causes weight loss.
• It does not cause release of insulin, therefore less chances of hypoglycemia.
72. Ans. (b) Taken just before a meal, it limits post-prandial hyperglycemia in type 2 diabetes mellitus (Ref: KDT 6/e p269)
• Nateglinide and repaglinide are short acting oral hypoglycemic agents.
• These are used to limit the post-prandial hyperglycemia.
• Like sulfonylureas, these drugs also act by blocking K + channels in the β-cells of pancreas that lead to depolarization
and release of insulin.
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73. Ans. (d) They are used first in most cases of uncomplicated mild to moderate type 2 diabetes (Ref: KDT 6/e p271)
74. Ans. (b) Glipizide (Ref: KDT 6/e p266, 267)
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