Endocrine & Metabolic Drugs Practice Exam Answers

Endocrine & Metabolic Drugs Practice Exam Answers

 

What is the mechanism of action of insulin?

 

Insulin binds to insulin receptors on target cells, activating a tyrosine kinase signaling pathway, which increases glucose uptake by cells via GLUT-4 transporters.

Explanation: Insulin facilitates glucose entry into muscle and fat cells, reducing blood glucose levels.

 

What is the primary function of glucagon?

 

Glucagon increases blood glucose levels by stimulating glycogenolysis and gluconeogenesis in the liver.

Explanation: Glucagon is the counter-regulatory hormone to insulin, essential during hypoglycemia.

 

Name a long-acting insulin preparation.

 

Insulin glargine.

Explanation: Insulin glargine has a prolonged duration due to its formulation, allowing for once-daily dosing.

 

What class of drugs does metformin belong to?

 

Biguanides.

Explanation: Metformin improves insulin sensitivity and decreases hepatic glucose production.

 

What are thiazolidinediones (TZDs), and how do they work?

 

TZDs (e.g., pioglitazone) enhance insulin sensitivity by activating PPAR-gamma receptors.

Explanation: These drugs target adipose tissue, muscle, and liver, improving glucose uptake and utilization.

 

What is the first-line therapy for Type 2 Diabetes Mellitus?

 

Metformin.

Explanation: Metformin is preferred due to its efficacy, safety profile, and cardiovascular benefits.

 

Name two side effects of sulfonylureas.

 

Hypoglycemia and weight gain.

Explanation: Sulfonylureas stimulate insulin release, which can cause these adverse effects.

 

What is the mechanism of SGLT-2 inhibitors like empagliflozin?

 

Inhibition of sodium-glucose co-transporter 2 in the renal tubules reduces glucose reabsorption.

Explanation: SGLT-2 inhibitors lower blood glucose levels by promoting glucosuria.

 

Which GLP-1 receptor agonist has cardiovascular benefits?

 

Liraglutide.

Explanation: Liraglutide improves glycemic control and reduces the risk of major adverse cardiovascular events.

 

What is the role of DPP-4 inhibitors in diabetes?

 

They prevent the degradation of incretins, enhancing insulin secretion and reducing glucagon levels.

Explanation: DPP-4 inhibitors like sitagliptin are used as adjuncts to improve glycemic control.

 

What is the drug of choice for hypothyroidism?

 

Levothyroxine.

Explanation: Levothyroxine is synthetic T4, which is converted to active T3 in the body.

 

What is the mechanism of action of methimazole?

 

It inhibits thyroid peroxidase, reducing the synthesis of thyroid hormones.

Explanation: Methimazole is used in hyperthyroidism to block thyroid hormone production.

 

Which drug is used in a thyroid storm?

 

Propranolol.

Explanation: Beta-blockers reduce the peripheral effects of thyroid hormones and control symptoms.

 

Why is iodine used before thyroid surgery?

 

To decrease thyroid vascularity and hormone release.

Explanation: Lugol’s iodine reduces surgical complications and thyroid hormone levels.

 

Name a radioactive iodine isotope used for hyperthyroidism.

 

I-131.

Explanation: I-131 destroys overactive thyroid tissue by emitting beta radiation.

 

What is the mechanism of bisphosphonates?

 

Bisphosphonates inhibit osteoclast-mediated bone resorption.

Explanation: Drugs like alendronate prevent bone loss in osteoporosis.

 

Name a monoclonal antibody used in osteoporosis treatment.

 

Denosumab.

Explanation: Denosumab inhibits RANKL, reducing osteoclast activity and bone resorption.

 

What is the primary side effect of bisphosphonates?

 

Esophageal irritation.

Explanation: Patients are advised to stay upright for 30 minutes after taking the drug.

 

What is the role of teriparatide in osteoporosis?

 

It is a recombinant PTH analog that stimulates bone formation.

Explanation: Teriparatide increases osteoblast activity, unlike other treatments that mainly prevent bone resorption.

 

Why is vitamin D supplementation essential in osteoporosis?

 

It aids calcium absorption from the gastrointestinal tract.

Explanation: Adequate calcium and vitamin D levels are necessary for effective osteoporosis management.