Understanding Triglycerides and Cholesterol

Triglycerides and Cholesterol

• Lipids are water-insoluble fats that require binding to apolipoproteins for transport.
• The liver is a key organ for lipid metabolism and cholesterol production.
• Lipoprotein is a combination of triglyceride or cholesterol with apolipoprotein.
• Very-low-density lipoprotein (VLDL) is produced by the liver and transports endogenous lipids for the cells.
• Low-density lipoprotein (LDL) and High-density lipoprotein (HDL) are present
• HDL is responsible for "recycling" cholesterol and is termed "good cholesterol."

Cholesterol and Coronary Heart Disease Risk

• Low HDL levels are less than 40 mg/dL.
• Total cholesterol levels of 300 mg/dL is three to four times greater than levels in patients with levels less than 200 mg/dL.
• Increased cholesterol leads to an increased incidence of death.

Treatment Guidelines

• Antilipemic drugs are used to lower lipid levels as an addition to diet therapy.
• Drug choice depends on the patient's lipid profile.
• Antilipemics are recommended for those with clinical atherosclerotic cardiovascular disease.
• Antilipemics are recommended for those with LDL cholesterol ≥ 190mg/dL.
• Antilipemics are recommended for diabetics aged 40-75 with LDL levels between 70 to 189mg/dL without CVD.
• Antilipemics are recommended for those without CVD or diabetes but with LDL levels between 70 to 189mg/dL and high CVD risk factors within 10 years.
• Non-drug approaches should be attempted for at least 6 months before considering drug therapy.

Antilipemics

• Classes of antilipemic drugs include HMG-CoA reductase inhibitors (HMGs or statins).
• Bile acid sequestrants are a class of antilipemics
• Niacin (vitamin B3 or nicotinic acid) is a type of antilipemic
• Fibric acid derivatives (fibrates)
• Cholesterol absorption inhibitors (Zetia) can be used as antilipemics
• Herbal medications can be used as antilipemics

HMG-CoA Reductase Inhibitors

• HMG-CoA reductase inhibitors (HMGs, or statins) are potent LDL reducers
• Examples of HMG-CoA reductase inhibitors include pravastatin (Pravachol), simvastatin (Zocor), atorvastatin (Lipitor), fluvastatin (Lescol), rosuvastatin (Crestor), and pitavastatin (Livalo).
• HMG-CoA reductase inhibitors should be administered orally in the evening with food.
• Baseline cholesterol, HDL, LDL, triglycerides, as well as renal and liver function tests should be monitored before and periodically during therapy.
• Effects may take 6-8 weeks to appear.

HMG-CoA Reductase Inhibitors Action and Side Effects

• HMG-CoA reductase inhibitors inhibit HMG-CoA reductase, used by the liver to produce cholesterol.
• HMG-CoA reductase inhibitors decrease the rate of cholesterol production.
• First-line drug therapy for hypercholesterolemia
• HMG-CoA reductase inhibitors reduce LDL levels, increase HDL levels, and reduce triglycerides.
• HMG-CoA reductase inhibitors can cause mild, transient GI disturbances, rash, headache, or myopathy (muscle pain), potentially leading to rhabdomyolysis.
• HMG-CoA reductase inhibitors can cause elevated liver enzymes or liver disease and peripheral neuropathy.

HMG-CoA Reductase Inhibitors Interactions

• HMG-CoA reductase inhibitors interact with oral anticoagulants and various drugs, including erythromycin, antifungals, verapamil, diltiazem, HIV protease inhibitors, and amiodarone.
• Grapefruit juice delays metabolism of statins.

Bile Acid Sequestrants

• Bile acid sequestrants may be used with statins as second-line drugs
• Examples of bile acid sequestrants include cholestyramine (Questran), colestipol hydrochloride (Colestid), and colesevelam (Welchol).
• Colesevelam (Welchol) is available in tablet form.
• Cholestyramine (Questran) is supplied as a powder.
• Colesevelam (Welchol should be taken orally in tablet form with food and 8oz of water, and not with other medications.

Bile Acid Sequestrants Action and Side Effects

• Bile acid sequestrants act by preventing the reabsorption of bile acids from the small intestine, which are needed for cholesterol absorption.
• Bile acid sequestrants can cause constipation, heartburn, nausea, belching, and bloating which can get better over time.

Niacin

• Niacin is also known as Vitamin B3
• Niacin is effective, inexpensive and often used in combination with other lipid-lowering drugs
• Niacin will decrease triglycerides, total serum cholesterol, and LDL levels, and increase HDL levels

Niacin Action and Side Effects

• Niacin increases activity of lipase, which breaks down lipids
• Niacin reduces the metabolism of cholesterol and triglycerides
• Niacin will cause flushing (caused by histamine release), pruritus, GI distress, hyperglycemia, and hepatotoxicity

Fibric Acid Derivatives

• Fibric acid derivatives (fibrates) include gemfibrozil (Lopid) and fenofibrate (Tricor)
• Fibric acid derivatives decrease triglyceride levels and increase HDL.

Fibric Acid Derivatives Action and Side Effects

• Fibric acid derivatives activate lipase, which breaks down cholesterol.
• Fibric acid derivatives suppress the release of free fatty acid from adipose tissue.
• Fibric acid derivatives inhibit the synthesis of triglycerides in the liver.
• Fibric acid derivatives increase the secretion of cholesterol in the bile.
• Fibric acid derivatives may cause abdominal discomfort, diarrhea, nausea, blurred vision, headache, increased risk of gallstones, prolonged prothrombin time, abnormal liver studies, and myopathy.

Fibric Acid Derivatives Interactions

• Fibric acid derivatives will interact with oral anticoagulants and statins
• The risk for myositis, myalgias, and rhabdomyolysis is increased when taking fibric acid derivatives
• Fibric acid derivatives can cause decreased hemoglobin levels, hematocrit value, and white blood cell counts
• Fibric acid derivatives may lead to increased activated clotting time, lactate dehydrogenase levels, and bilirubin levels

Cholesterol Absorption Inhibitor

• Ezetimibe (Zetia) is a cholesterol absorption inhibitor
• Ezetimibe is often combined with a statin drug
• Ezetimibe is recommended when patients have not responded to other therapies
• Ezetimibe can lower total cholesterol, LDL, and triglyceride levels, and can increase HDL levels

Cholesterol Absorption Inhibitor Action and Side Effects

• Cholesterol absorption inhibitors inhibit the absorption of cholesterol secreted in the bile and from food
• Cholesterol absorption inhibitors can cause hepatitis and myopathy
• Cholesterol absorption inhibitors are contraindicated in patients who have mild to severe liver disorders

Herbal Products: Omega-3 Fatty Acids

• Omega-3 fatty acids are a herbal product that are used to reduce cholesterol and may cause rash, belching, and allergic reactions
• Omega-3 may have potential interactions with anticoagulant drugs

Herbal Products: Garlic

• Garlic is a herbal product that is a lipid reducer but can cause adverse effects of dermatitis, vomiting, diarrhea, flatulence, and antiplatelet activity
• Garlic can interact with warfarin and diazepam, and may enhance bleeding when taken with NSAIDs

Herbal Products: Flax

• Flax is a herbal product where both the seed and oil of the flax plant are used to lower cholesterol
• Flax may cause diarrhea and allergic reactions
• Flax may interact with antidiabetic and anticoagulant drugs

Nursing Implications

• Contraindications include biliary obstruction, liver dysfunction, and active liver disease
• Baseline liver function studies should be obtained
• Patients on long-term therapy may need supplemental fat-soluble vitamins (A, D, K)
• Take with meals to decrease GI upset
• Powder forms must be taken with a liquid, mixed thoroughly but not stirred, and NEVER taken dry
• Other medications should be taken 1 hour before or 4 to 6 hours after meals to avoid interference with absorption
• To minimize adverse effects of niacin, start on a low initial dose and gradually increase it, and take with meals
• Small doses of aspirin or NSAIDs may be taken 30 minutes before niacin to minimize cutaneous flushing
• Patients should be informed that these drugs may take several weeks to show effectiveness
• Patients should report persistent GI upset, constipation, abnormal or unusual bleeding, and yellow discoloration of the skin
• Monitor for adverse and therapeutic effects, including liver enzyme studies, reduced cholesterol, and reduced triglyceride levels

SDOH

• Zocor costs $195.65 without insurance.
• Generic lipitor costs $126.99 without insurance.
• Cholestyramine costs $148.99
• Lipid panel can range from $200 to $843 without insurance and $19 with private insurance or Medicare