HMG-CoA inhibitors are antihyperlipidemic. They are a fungal metabolite that inhibits the enzyme that catalyzes the first step in the cholesterol synthesis pathway in humans, resuling in a decrease in serum cholesterol and serum LDLs (associated with increased risk of CAD); either an increase or no change in serum HDLs (associated with decreased risk of CAD); and a decrease in triglycerides.

Indications

Adjunct to diet in the treatment of elevated total and LDL cholesterol in patients with primary hypercholesterolemia (types IIa and IIb) whose response to dietary restriction of saturated fat and cholesterol and other non pharmacologic measures has not been ad- equate

Primary prevention of coronary events (lovastatin, pravastatin)

Secondary prevention of CV events (fluvastatin, lovastatin, pravastatin, simvastatin)

Contraindications and cautions

Contraindicated with allergy to HMG-CoA inhibitors, fungal byproducts, pregnancy, or lactation, concurrent gemfibrozil therapy.

Use cautiously with impaired hepatic function, cataracts.

Adverse effects

CNS: Headache, blurred vision, dizziness, insomnia, fatigue, muscle cramps, cataracts

GI: Flatulence, abdominal pain, cramps, constipation, nausea, vomiting, heartburn, elevations of CK, alkaline phosphatase, and transaminases

Musculoskeletal: Rhabdomyolysis with possible renal failure

Interactions

Drug-drug

Monitor patients receiving HMG-CoA inhibitors for possible severe myopathy or rhabdomyolysis if taken with cyclosporine, erythromycin, gemfibrozil, niacin, azole antifungals Drug-food

Risk of increased serum levels if combined with grapefruit juice

Nursing considerations

Assessment

History: Allergy to HMG-CoA inhibitors, fungal byproducts; impaired hepatic function; cataracts; pregnancy; lactation

Physical: Orientation, affect, ophthalmologic examination; liver evaluation; lipid studies, LFTs

Interventions

Administer drug at bedtime; highest rates of cholesterol synthesis are between midnight and 5 AM.

Consult with dietitian about low-cholesterol diets.

Arrange for diet and exercise consultation.

Arrange for regular follow-up during longterm therapy.

Provide comfort measures to deal with headache, muscle cramps, nausea.

Arrange for periodic ophthalmologic exam- ination to check for cataract development.

Offer support and encouragement to deal with disease, diet, drug therapy, and follow-up.

Teaching points

Take these drugs at bedtime.

Institute appropriate diet changes.

Use contraceptive measures to avoid pregnancy while using these drugs.

Avoid grapefruit juice while taking these drugs.

You may experience these side effects: Nausea (eat frequent small meals); headache, muscle and joint aches and pains (may lessen with time).

Have periodic ophthalmic examinations while you are using these drugs.

Report severe GI upset, changes in vision, unusual bleeding or bruising, dark urine or light-colored stools; muscle pain, weakness.

Representative drugs

atorvastatin

fluvastatin

lovastatin

pitavastatin

pravastatin

rosuvastatin

simvastatin