HMG-COA reductase inhibitors include- Fluvastatin, Lovastatin, Pravastatin, Simvastatin

Refer - Lovastatin 

Immunosuppressive drugs (cyclosporin), itraconazole, gemfibrozil, niacin, or erythromycin with concurrent simvastatin may increase risk of rhabdomyolysis & acute renal failure. Simvastatin may slightly enhance the anticoagulant effect of warfarin.

Prothrombin time must be closely monitored in patients taking statins with anticoagulants. Simvastatin may cause slight elevation of serum digoxin when used concurrently.

Cholestyramine or colestipol may decrease the bioavailabilty of simvastatin when used concurrently. It is suggested that simvastatin be given 4 hrs after cholestyramine or colestipol.

Primary hypercholesterolaemias 

HMG-COA reductase inhibitors include- Fluvastatin, Lovastatin, Pravastatin, Simvastatin

INFORMATION UP DATE

Adverse reactions are usually mild and transcient. These include headache, nausea, flatulance, heart burn, diarrhoea/constipation, abdominal pain, cramps, rarely myopathy features like myalgia, & muscle weakness have been reported.

Rhabdomyolysis with acute renal failure may also occur.

Elevation of the plasma concentration of the muscle isozyme of creatinine phosphokinase & serum transamminases reported. Hypersensitivity, lens opacities, blurring of vision, dizziness, loss of libido, erecetile dyfunction, depression, insomnia & upper respiratory symptoms, are also reported..

Hypersensitivity, active liver disease or unexplained persistent elevations of serum transamminases.

Pregnacy and lactation.

Dosage:

Initial dose- 5 to 10mg once daily in the evening. Consider starting dose of 5mg/day

Elderly- consider starting dose of 5mg/day.

1. May cause photosentivity (sensitivity to sunlight) . Avoid prolonged exposure to the sun and othe ultraviolet light.

2. Use sunscreens and wear protective clothing until tolerance is determined

3. Promptly report unexplained muscle pain, tenderness or weakness, especially if accompanied by fever or malaise

4. Follow dietary recommendations.

5. Take lovastatin with meals, fluvastatin and simvastatin may be taken without regrads to meals.

Pharmacology:

Simavastatin is an HMG-CoA reductase inhibitor derived synthetically from fermented product of Aspergillus terreus. It is a prodrug which is activated in the liver by hydrolysis to form the active beta-hydroxyacid derivative. This active form is a competitive and reversible inhibitor of HMG-CoA reductase, the enzyme responsible for conversion of HMG-CoA to mevalonic acid, an early and rate-limiting step in the biosynthesis of cholestrol.

Pharmacokinetics:

Folowing absoption from thr GIT, simvastatin undergoes extensive first pass metabolism in liver, its primary site of action. Consequently, the availability of the drug to the general circulation is low and variable. Under 5% of the oral dose has been reported to reach the circulation as the active metabolite. Both simvastin and its beta-hydoxyacid metabolite are highly protein bound (95%). Simvastin is eliminated 13% in urine and 60% via the rectal route.

Simvastatin may be taken without regard to meals.

No data on pregnant women. Given to women of child bearing age only if they are highly unlikely to conceive.

Lactation:

Simvastatin is excreted in human breast milk. Because of the potential for serious adverse reactions in nursing infants, caution women taking these drugs not to nurse their infants.

Children:

Safety and efficacy in individuals below 18 years old have not been established