Antihyperlipidemics are medications used to treat increased levels of lipids in the blood, like cholesterol, particularly low density lipoprotein, or LDL cholesterol; as well as triglycerides. Therefore, they’re also indicated in coronary artery disease therapy. Antihyperlipidemics include different classes of medications, among which are bile acid sequestrants, like cholestyramine, colesevelam and colestipol, as well as cholesterol absorption inhibitors like ezetimibe. All of them are administered orally.
Once administered, bile acid sequestrants, which are positively charged molecules, bind to the negatively charged bile acid in the intestine, preventing it from being reabsorbed. In turn, the liver compensates by increasing the production of bile salts, which uses up a lot of cholesterol. To get more cholesterol from the rest of the body, the liver increases uptake of LDLs, lowering its levels in the blood. The downside is that this also increases endogenous cholesterol and triglyceride synthesis.
And then cholesterol absorption inhibitors work by blocking a transport protein that mediates cholesterol absorption in the small intestine. This medication is mainly used to treat high levels of LDL and is typically used in combination with other lipid lowering agents like statins.
Common side effects of bile acid sequestrants include gastrointestinal disturbances, mostly constipation, abdominal pain, bloating, and nausea; and they can decrease absorption of fat soluble vitamins such as A,D,E and K; and with decreased vitamin K absorption, increased bleeding risk can ensue. Similarly, all bile acid sequestrants can decrease the absorption and effect of fat-soluble medications like digoxin, oral contraceptives and warfarin. Side effects of ezetimibe include headache, arthralgias, and myalgias; and rarely, rhabdomyolysis.
As far as contraindications go, bile acid sequestrants shouldn’t be used in clients with complete biliary obstruction or hypertriglyceridemia; and colesevelam in particular shouldn’t be used in clients with a history of bowel obstruction, type 1 diabetes, or pancreatitis. Cholestyramine should also be used with caution during pregnancy, and in clients with renal impairment. Ezetimibe is contraindicated in clients with severe hepatic disease who are also taking a statin, and should be used with caution when renal impairment is present.
Alright, if a client with dyslipidemia is prescribed a bile acid sequestrant like colesevelam as part of their antihyperlipidemic therapy, start by performing a baseline assessment, including vital signs, current nutritional habits, and cardiovascular status; making note of any signs of coronary artery disease, such as chest pain or shortness of breath. Lastly, review your client’s laboratory test results, including renal and hepatic function, blood glucose, and lipid panel, which includes total cholesterol, triglycerides, HDL, and LDL.
