ANTILIPEMICS

LILLEY, READING & WORKBOOK: CHAP 28

Cardiovascular System

Antilipemics

Drugs used to lower lipid levels

Triglycerides and Cholesterol

Two primary forms of lipids in the blood

Water-insoluble fats that must be bound to apolipoproteins, specialized lipid-carrying proteins

Lipoprotein is the combination of triglyceride or cholesterol with a polipoprotein

Lipoproteins

Very-low-density lipoprotein (VLDL) Produced by the liver Transports endogenous lipids to the cells

Low-density lipoprotein (LDL)

High-density lipoprotein (HDL) Responsible for “recycling” of cholesterol Also known as “good cholesterol”

Coronary Heart Disease

The risk of CHD in patients with cholesterol levels of 300 mg/dL is three to four times greater than that in patients with levels less than 200 mg/dL

Coronary Heart DiseasePositive Risk Factors

Age Male 45 years or older Female 55 years or older, or women with premature

menopause not on estrogen replacement therapy

Family history: history of premature CHDCurrent cigarette smokerHypertension

BP 140/90 or higher, or on antihypertensive medication

Low HDL levels: less than 35 mg/dLDiabetes mellitus

Treatment Guidelines

Antilipemic drugs are used as an adjunct to diet therapy

Drug choice based on the specific lipid profile of the patient

All reasonable non-drug means of controlling blood cholesterol levels (e.g., diet, exercise) should be tried for at least 6 months and found to fail before drug therapy is considered

Antilipemics

HMG-CoA reductase inhibitors (HMGs, or statins)

Bile acid sequestrantsNiacin (nicotinic acid)Fibric acid derivativesCholesterol absorption inhibitorCombination drugs

Antilipemics: HMG-CoA Reductase

Inhibitors (HMGs, or statins)

Most potent LDL reducers

lovastatin (Mevacor)pravastatin (Pravachol)simvastatin (Zocor)atorvastatin (Lipitor)fluvastatin (Lescol)

HMG-CoA Reductase Inhibitors (statins)

Indications

First-line drug therapy for hypercholesterolemia

Treatment of types IIa and IIb hyperlipidemias Reduce LDL levels by 30% to 40% Increase HDL levels by 2% to 15% Reduce triglycerides by 10% to 30%

HMG-CoA Reductase Inhibitors (statins)

Adverse effects

Mild, transient GI disturbancesRashHeadacheMyopathy (muscle pain), possibly leading to

the serious condition rhabdomyolysisElevations in liver enzymes or liver disease

Bile Acid Sequestrants

cholestyramine (Questran)

colestipol hydrochloride (Colestid)

colesevelam (tablet form)

Also called bile acid–binding resins and ion-exchange resins

Bile Acid Sequestrants

Mechanism of actionPrevent resorption of bile acids from small intestineBile acids are necessary for absorption

of cholesterol

IndicationsType II hyperlipoproteinemiaRelief of pruritus associated with partial

biliary obstruction (cholestyramine)May be used along with statins

Bile Acid Sequestrants

Adverse effects

Constipation

Heartburn, nausea, belching, bloating These adverse effects tend to disappear over

time

Niacin (Nicotinic Acid)

Vitamin B3

Lipid-lowering properties require much higher doses than when used as a vitamin

Effective, inexpensive, often used in combination with other lipid-lowering drugs

Niacin (Nicotinic Acid)

Mechanism of actionIncreases activity of lipase, which breaks down lipidsReduces the metabolism of cholesterol and

triglycerides

IndicationsEffective in lowering triglyceride, total serum

cholesterol, and LDL levelsIncreases HDL levelsEffective in the treatment of types IIa, IIb, III, IV, and

V hyperlipidemias

Niacin (Nicotinic Acid)

Adverse effects

Flushing (due to histamine release)PruritusGI distress

Fibric Acid Derivatives

Also known as fibrates

gemfibrozil (Lopid)fenofibrate (Tricor)

Fibric Acid Derivatives

Mechanism of actionActivate lipase, which breaks down cholesterolSuppress release of free fatty acid from the adipose

tissue, inhibit synthesis of triglycerides in the liver, and increase the secretion of cholesterol in the bile

IndicationsTreatment of types III, IV, and V hyperlipidemias

Drug EffectsDecrease the triglyceride levelsIncrease HDL by as much as 25%

Fibric Acid Derivatives

Adverse effects

Abdominal discomfort, diarrhea, nauseaBlurred vision, headacheIncreased risk of gallstonesProlonged prothrombin timeLiver studies may show increased

function

Cholesterol Absorption Inhibitor

ezetimibe (Zetia)

Inhibits absorption of cholesterol and related sterols from the small intestine

Results in reduced total cholesterol, LDL, triglylceride levels

Also increases HDL levelsWorks well when taken with a statin drug

Nursing Implications Patient Education

Before beginning therapy, obtain a thorough health and medication history

Assess dietary patterns, exercise level, weight, height, VS, tobacco and alcohol use, family history

Assess for contraindications, conditions that require cautious use, and drug interactions

Nursing Implications Patient Education

Contraindications include biliary obstruction, liver dysfunction, active liver disease

Obtain baseline liver function studies

Patients on long-term therapy may need supplemental fat-soluble vitamins (A, D, K)

Take with meals to decrease GI upset

Nursing Implications Patient Education

Patient must be counseled concerning diet and nutrition on an ongoing basis

Instruct on proper procedure for taking the medications

Powder forms must be taken with a liquid, mixed thoroughly but not stirred, and NEVER taken dry

Nursing Implications Patient Education

Other medications should be taken 1 hour before or 4 to 6 hours after meals to avoid interference with absorption

Clofibrate often causes constipation; instruct patients to increase fiber and fluid intake to offset this effect

Nursing Implications Patient Education

To minimize adverse effects of niacin, start on low initial dose and gradually increase it, and take with meals

Small doses of aspirin or NSAIDs may be taken 30 minutes before niacin to minimize cutaneous flushing

Inform patients that these drugs may take several weeks to show effectiveness

Nursing Implications Patient Education

Instruct patients to report persistent GI upset, constipation, abnormal or unusual bleeding, and yellow discoloration of the skin

Monitor for adverse effects, including increased liver enzyme studies

Monitor for therapeutic effects Reduced cholesterol and triglyceride levels

Review

In addition to drug therapy, the patient should be encouraged to do which of the following to treat hyperlipidemia? (Select all that apply.)

1. Reduce cholesterol and fats in diet.2. Reduce weight.3. Decrease exercise.4. Increase use of polyunsaturated andmonounsaturated fats.

Review

Before initiating a statin drug, the premedication

assessment should include:

1. complete blood count (CBC).2. liver function studies.3. bleeding time.4. gastrointestinal (GI) series.

Review

Ezetimibe (Zetia) acts by:

1. an unknown mechanism of action.2. binding bile acids in the intestines.3. removing fat-soluble vitamins.4. blocking absorption of cholesterol bythe small intestines.