Dissolution of Gallstones with Simvastatin, an HMG CoA Reductase Inhibitor

The aim of this study was to determine whether12 months of therapy with Simvastatin, an HMG CoAreductase inhibitor, would dissolve gallstones.Twenty-seven subjects entered the study, all had afasting oral cholecystogram, ultrasound examination,and fasting serum lipids prior to therapy. In addition,22 subjects had their gallbladder ejection fraction,after CCK, determined by radionucleotide scanning. Eleven subjects had the cholesterol saturationindex (CSI) of bile calculated before and at the end of12 months of therapy. Of the 27 subjects, 26 completed12 months of treatment with Simvastatin 20 mg daily. There was a significant fall in thetotal serum cholesterol (27%, P < 0.0001), LDLcholesterol (31%, P < 0.0001), triglyceride (34%, P< 0.0001) but no change in HDL after 12 months oftherapy. Simvastatin treatment resulted in a 28% fall in the CSI ofbile at the end of therapy (P < 0.01). Theconcentrations of individual bile acids did not changewith therapy, and apart from a slight but significantincrease in arachidonate, there were no othersignificant changes in the fatty acid composition of thebiliary phospholipids. After 12 months of Simvastatintherapy there was a small decrease in the gallstonediameter but complete dissolution of gallstones was notachieved in any subjects. In conclusion 12 months oftherapy with Simvastatin was effective in lowering theserum lipids and the CSI of bile but was not effective in dissolving gallstones.