Simvastatin
Simvastatin is a statin that inhibits HMG-CoA reductase, the enzyme governing cholesterol synthesis in the liver, prompting the liver to clear more LDL cholesterol from the blood. It is used to lower cholesterol, with LDL and total cholesterol tracking the response.
It suits evening dosing and can be taken with or without food, but grapefruit is avoided: it blocks the enzyme that breaks simvastatin down, so blood levels climb and with them the risk of muscle damage. The same mechanism rules out clarithromycin and itraconazole, and amlodipine raises levels enough to warrant caution. ALT is monitored for liver strain, and creatine kinase is the test used when muscle symptoms suggest myopathy; the drug also depletes coenzyme Q10. It is not used in pregnancy, since cholesterol is essential to fetal development.
Unexplained muscle pain, tenderness or weakness, particularly alongside dark urine or fever, should be assessed by a doctor without delay, as should jaundice, dark urine with abdominal pain, or unusual tiredness. Pregnancy, planned or confirmed, is a reason to see a doctor rather than stopping or continuing alone.
Reference information, not medical advice. Discuss any change with your doctor.