Prescription medications

Statins lower LDL-C and total cholesterol (on average, by up to 60% and 40%, respectively), and raise HDL (on average, by up to 10%). They may also lower triglycerides (TG) (on average, by up to 45%). Some statin medications may also result in a lower TC/HDL ratio. Statins work by blocking cholesterol production in the liver.

Most people will be able to reach their cholesterol targets by taking a statin alone. In some cases, combination therapy (i.e., more than one medication) may be needed. Statins are often combined with other cholesterol-lowering medications in the resin class or cholesterol absorption inhibitor class.

Statins available in Canada include atorvastatin, fluvastatin, lovastatin, pravastatin, rosuvastatin, and simvastatin.

The main side effects of statins are mild stomach upset, headache, muscle soreness, and muscle pain. Side effects may be associated with people taking higher statin doses, or people who are already at risk of side effects due to their pre-existing medical conditions or other medications. Muscle pain may be a sign of muscle damage caused by these medications. People who notice muscle pain should see their doctor right away. Pregnant or breast-feeding women should not use statins, as these medications may harm the baby. People with liver disease should not take statins, as they make liver damage worse. All people taking a statin need to have regular tests to check their liver function.

In general, statins should not be used with gemfibrozil, as this increases the risk of muscle damage. Statins may also increase the effects of warfarin, a blood-thinning medication. Atorvastatin, lovastatin, and simvastatin also interact with erythromycin, cyclosporine, diltiazem, medications for people who are HIV-positive, and niacin. Fluvastatin interacts with cimetidine, ranitidine, omeprazole, and rifampin. Rosuvastatin should be taken two hours apart from antacids, and should not be taken with cyclosporine. Consult your pharmacist or doctor if you are concerned that one of your medications may be interacting with your statin.

Cholesterol absorption inhibitors are a new type of medication to help treat high cholesterol. Ezetimibe is the only medication in this group that is currently available in Canada. Ezetimibe works by blocking cholesterol from being absorbed in the intestine; in one study, it blocked up to 54% of cholesterol. It may be used alone or along with a statin to lower LDL-C and TG and to increase HDL-C.

Ezetimibe should not be used by people with severe liver disease. The effects of this medication during pregnancy are unclear, so it should be used with caution by mothers-to-be. Children under 10 should not use ezetimibe.

The main side effects are headache, abdominal pain, and diarrhea. Ezetimibe should not be used with fibrates. People taking cyclosporine (a medication taken after people receive an organ transplant) should have their cyclosporine levels checked if they are taking ezetimibe. People taking a resin (see below) should take it 2 hours before or 4 hours after ezetimibe. Otherwise, the resin will block ezetimibe from being absorbed into the body.

Resins lower LDL (on average, by up to 30%) and raise HDL (on average, by up to 3%). They work by decreasing the absorption of cholesterol and increasing the breakdown of LDL. The two resins available in Canada are cholestyramine and colestipol.

The main side effects are constipation, bloating, gas, and a feeling of fullness. Resins also increase TG. People taking resins should have their liver function checked on a regular basis. Resins, on the advice of a physician, can be used for lowering cholesterol in women who are pregnant and in children (over two years of age).

Resins can block the absorption of other medications and fat-soluble vitamins (vitamins A, D, E, and K). They should be given one to two hours before or four hours after other medications.

Fibrates lower TG (on average, by up to 50%) and increase HDL (on average, by up to 30%). Some fibrates (such as the newer medications bezafibrate and fenofibrate) also lower LDL (on average, by up to 10%). There are four fibrates available in Canada: bezafibrate, fenofibrate, gemfibrozil, and clofibrate. They work by blocking cholesterol production and increasing cholesterol breakdown.

The main side effects are nausea, abdominal pain, gas, and muscle aches. People taking this medication should have their liver and kidney functions checked on a regular basis. People with poor kidney function may need a lower dose. Fibrates can increase the effects of blood thinners, such as warfarin. Gemfibrozil may increase the risk of muscle damage if taken with a statin.

For additional information on treatment of high cholesterol, click here.