Mechanism of effect
Lovastatin is a specific inhibitor of HMG-CoA reductase, the enzyme which catalyzes the conversion of HMG-CoA to mevalonate. The conversion of HMG-CoA to mevalonate is an early step in the biosynthetic pathway for cholesterol.
Pharmacodynamic
Lovastatin lowers hepatic cholesterol synthesis by competitively inhibiting HMG-CoA reductase,
Pharmacokinetics
Studies suggest that <5% of the oral dose reaches the general circulation as active inhibitors. Time to peak serum concentration is 2-4 hours. Lovastatin is able to cross the blood-brain-barrier and placenta. Lovastatin and its β-hydroxyacid metabolites are highly protein bound (>95%).Lovastatin undergoes extensive first-pass extraction in the liver. 83% of the orally administered dose is excreted in bile and 10% is excreted in urine. Half life: 3 hours.
Dosage
Usual Adult Dose for Hyperlipidemia Initial dose: 20 mg orally once a day with the evening meal. Maintenance dose: 10 to 80 mg orally once a day or in 1 or 2 divided doses. Comment: Lower doses are suggested for a smaller reduction in cholesterol level. Usual Pediatric Dose for Heterozygous Familial Hypercholesterolemia Initial: 10 to 17 years: 10 mg orally once a day Maintenance: 10 to 17 years: 10 to 40 mg orally once a day Comments: Dosage adjustments should be made no earlier than every 4 weeks, adding no more than 10 mg to the current dose each time.
Drug contraindications
Pregnancy , Lactation , hypersensitivity to drug or its components. , Active liver diseaseSide effects
nausea , Headache , constipation , abdominal pain , dizziness , Blurred vision , Hepatic dysfunction , rash , Diarrhea , dyspepsia , myalgia , Arthralgia , flatulence , hepatitisInteractions
Ipratropium bromide , Imatinib , Bosentan , Zafirlukast , Cyclosporine , Amiodarone , Erythromycin , Itraconazole , Danazol , Diltiazem , Fluconazole , Warfarin , Verapamil , Voriconazole , Ketoconazole , Clarithromycin , Clofibrate , Diltigel , Disulfiram , Bisoprolol , Rifabutin , Rifapentine , Darunavir , Nefazodone , ritonavir , saquinavir , nelfinavir , Prednisolone , Mifepristone , Indinavir , Daptomycin , Idelalisib , Efavirenz , Tipranavir , Etravirine , Darifenacin , Mibefradil , Nicardipine , cobicistat , Delavirdine , Oxiconazole , Butabarbital , ELBASVIR/GRAZOPREVIR , Troleandomycin , Nitrendipine , riociguat , tucatinib , Ombitasvir, Paritaprevir, and RitonavirAlerts
1-Lovastatin, like other inhibitors of HMG-CoA reductase, occasionally causes myopathy manifested as muscle pain, tenderness or weakness with creatine kinase (CK) above 10 times the upper limit of normal (ULN). 2-Liver Dysfunction may occure.
Points of recommendation
1-It is recommended that liver function tests be performed prior to initiation of therapy in patients with a history of liver disease, or when otherwise clinically indicated. Discontinuation of lovastatin therapy is recommended if liver function tests (AST or ALT) persist at three times the upper limit of normal or greater. 2-Extended-release tablets of lovastatin should be swallowed whole and not chewed or crushed. 3-Patients should be advised to report promptly unexplained muscle pain, tenderness, or weakness particularly if accompanied by malaise or fever or if muscle signs and symptoms persist after discountinuing Lovastatin
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