SIMVASTATIN
| SIMVASTATIN (sim-vah-sta'-tin) Zocor Classifications: antilipemic; hmg-coa reductase inhibitor (statin); Therapeutic: antihyperlipemic; statin Prototype: Lovastatin Pregnancy Category: X |
Availability
5 mg, 10 mg, 20 mg, 40 mg, 80 mg tablets
Action
Inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase; similar in action to lovastatin but more potent. HMG-CoA reductase inhibitors increase HDL cholesterol, and decrease LDL cholesterol, and total cholesterol synthesis.
Therapeutic Effect
Effectiveness indicated by decreased serum triglycerides, decreased LDL, cholesterol, and modest increases in HDL cholesterol.
Uses
Hypercholesterolemia (alone or in combination with bile acid sequestrants), familial hypercholesterolemia. Reduces risk of coronary death and nonfatal MI.
Contraindications
Hypersensitivity to simvastatin; active liver disease, hepatic encephalopathy, hepatitis, jaundice, rhabdomyolysis; cholestasis; pregnancy (category X), children <10 y, lactation.
Cautious Use
Homozygous familial hypercholesterolemia, history of liver disease, alcoholics; renal disease, renal impairment; seizure disorder.
Route & Dosage
| Hypercholesterolemia Adult: PO 5–40 mg q.d. (max: 80 mg q.d.). Patients taking danazol or cyclosporine should not exceed 10 mg q.d. |
Administration
Oral- Adjust dosage usually at 4-wk intervals.
- Give in the evening.
- Store at 15°–30° C (59°–86° F).
Adverse Effects (≥1%)
CV: Angina. CNS: Dizziness, headache, vertigo, asthenia, fatigue, insomnia. GI: Nausea, diarrhea, vomiting, abdominal pain, constipation, flatulence, heartburn, transient elevations in liver transaminases, transient elevations in CPK. Body as a Whole: Fatigue. Respiratory: Rhinitis, cough.Interactions
Drug: May increase PT when administered with warfarin; cyclosporine, gemfibrozil, fenofibrate, clofibrate, antilipemic doses of niacin, fluconazole, itraconazole, ketoconazole, miconazole, nefazodone, nelfinavir, ritonavir, saquinavir, sildenafil, tacrolimus, clarithromycin, erythromycin, telithromycin may increase serum levels and increase risk of myopathy, rhabdomyolysis and acute kidney failure. Food: Grapefruit juice (>1 qt/d) may increase risk of myopathy, rhabdomyolysis. Herbal: Peppermint oil may increase plasma concentrations. St. John's wort may decrease efficacy.Pharmacokinetics
Absorption: Rapidly from GI tract. Onset: 2 wk. Peak: 4–6 wk. Distribution: 95% protein bound; achieves high liver concentrations; crosses placenta. Metabolism: Extensive first-pass metabolism in liver to its active metabolite. Elimination: 13% in urine, 60% in bile and feces.Nursing Implications
Assessment & Drug Effects
- Lab tests: Obtain baseline and periodic (q6mo) liver function during the first year and yearly thereafter. Monitor cholesterol levels throughout therapy.
- Monitor coagulation studies with patients receiving concurrent warfarin therapy. PT may be prolonged.
- Assess for and report unexplained muscle pain. Determine CPK level at onset of muscle pain.
Patient & Family Education
- Report unexplained muscle pain, tenderness, or weakness, especially if accompanied by malaise or fever, to physician.
- Report signs of bleeding to physician promptly when taking concurrent warfarin.
- Moderate intake of grapefruit juice while taking this medication.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug