Agents Used In Dyslidemias

Question 1

Name a few statin drugs.

Answer 1

Lovastatin, Fluvastatin, Pravastatin, Simvastatin, Atorvastatin, Rosuvastatin

Question 2

Name the bile acid binding resins.

Answer 2

Cholestyramine, Colestipol, Colesevelam

Question 3

How do statins work?

Answer 3

They inhibit the rate limiting step in cholesterol synthesis.
The conversion of HMG-CoA into mevalonate.

Statins are competitive inhibitors of HMG-CoA reductase.

Question 4

Name some side effect of statins.

Answer 4

• Myopathy, myalgia (patient complains of muscle pain) - Monitor CK!
• Rarely Rhabdomyolsis, usually only seen if statins are taken in combination with other drugs.
• Hepatotoxicity - check liver function tests (aminotransferases)

Question 5

Name some drug interactions of statins.

Answer 5

-gemfibrozil
(increased risk of rhabdomyolysis if taken with statins)
-cytochrome P450 inhibitors
(enhance toxicity of statins, inhibit breakdown therefore toxic build up of statins e.g. Macrolides, ketonazole, grapefruit!!!)

Question 6

What is the mechanism of the resins?

Answer 6

They bind bile acids in the intestinal lumen and prevent their reabsorption.

(Bile is made from cholesterol, and normally about 95% of cholesterol is reabsorbed from the GI as part of the enterohepatic circulation)

Question 7

What are the effects of resins?

Answer 7

Since they prevent reabsorption of bile acids -> decrease in bile acids is sensed by liver -> results in

1. enhanced conversion of cholesterol to bile acids in liver
2. Modest increase in plasma triglycerides
3. Increased uptake of LDL and IDL from plasma due to up-regulation of LDL receptors in liver.

Question 8

Resins are without effect in patients with…?

Answer 8

Homozygous familial hypercholesterolemia, who have no functioning receptors
( but may be useful in those with residual receptor function and in patients with heterozygous states)

Question 9

What are some of the therapeutic uses of resins?

Answer 9

• elevated LDL, like in primary hypercholesterolemia
  (If resins are used in patients with combined hyperlipidemias, may cause an increase in VLDLso requires addition of a fibrate or niacin)
• relieving pruritus, in patients who have cholestasis
  -digitalis toxicity, bc they bind digitalis glycosides

Question 10

Which drug has the greatest effect (increase) on HDL levels?

Answer 10

Niacin