Chapter 27 Antilipemic Drugs Copyright © 2014 by Mosby, an imprint of Elsevier Inc. Triglycerides and Cholesterol Two primary forms of lipids in the blood Water-insoluble fats that must be bound to apolipoproteins, specialized lipid-carrying proteins Lipoprotein is the combination of triglyceride or cholesterol with apolipoprotein Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 2 Lipoproteins Very-low-density lipoprotein (VLDL) Produced by the liver Transports endogenous lipids to the cells Low-density lipoprotein (LDL) High-density lipoprotein (HDL) Responsible for “recycling” of cholesterol Also known as “good cholesterol” Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 3 Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 4 Cholesterol and Coronary Heart Disease (CHD) The risk of CHD in patients with cholesterol levels of 300 mg/dL is three to four times greater than that in patients with levels less than 200 mg/dL. Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 5 Hyperlipidemias and Treatment Guidelines Antilipemic drugs Drugs used to lower lipid levels Used as an adjunct to diet therapy Drug choice based on the specific lipid profile of the patient (phenotyping) Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 6 Hyperlipidemias Treatment and Guidelines (cont’d) All reasonable nondrug means of controlling blood cholesterol levels (e.g., diet, exercise) should be tried for at least 6 months and found to fail before drug therapy is considered Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 7 Antilipemics HMG-CoA reductase inhibitors (HMGs, or statins) Bile acid sequestrants B vitamin niacin (vitamin B3, nicotinic acid) Fibric acid derivatives (fibrates) Cholesterol absorption inhibitor (Zetia) Combination drugs (Vytorin) Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 8 Antilipemics: HMG-CoA Reductase Inhibitors (HMGs, or statins) Most potent LDL reducers pravastatin (Pravachol) simvastatin (Zocor) atorvastatin (Lipitor) fluvastatin (Lescol) rosuvastatin (Crestor) pitavastatin (Livalo) Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 9 HMG-CoA Reductase Inhibitors: Mechanism of Action Inhibit HMG-CoA reductase, which is used by the liver to produce cholesterol Lower the rate of cholesterol production Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 10 HMG-CoA Reductase Inhibitors: Indications First-line drug therapy for hypercholesterolemia Treatment of types IIa and IIb hyperlipidemias Reduces LDL levels by 30% to 40% Increases HDL levels by 2% to 15% Reduces triglycerides by 10% to 30% Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 11 HMG-CoA Reductase Inhibitors: Adverse Effects Mild, transient GI disturbances Rash Headache Myopathy (muscle pain), possibly leading to the serious condition rhabdomyolysis Elevations in liver enzymes or liver disease Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 12 HMG-CoA Reductase Inhibitors: Interactions Oral anticoagulants Drugs metabolized by CYP3A4 erythromycin Azole antifungals verapamil diltiazem HIV protease inhibitors amiodarone Grapefruit juice Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 13 Classroom Response Question A patient with a new prescription for a HMGCoA (statin) drug is instructed to take the medication with the evening meal or at bedtime. The patient asks why it must be taken at this time of day. The reason is: A. The medication is better absorbed at this time. B. This timeframe correlates better with the natural diurnal rhythm of cholesterol production. C. There will be fewer adverse effects if taken at night instead of with the morning meal. D. This timing reduces the incidence of myopathy. Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 14 Bile Acid Sequestrants cholestyramine (Questran) colestipol (Colestid) colesevelam (Welchol) Also called bile acid–binding resins and ion-exchange resins Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 15 Bile Acid Sequestrants: Mechanism of Action Prevent resorption of bile acids from small intestine Bile acids are necessary for absorption of cholesterol Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 16 Bile Acid Sequestrants: Indications Type II hyperlipoproteinemia Relief of pruritus associated with partial biliary obstruction (cholestyramine) May be used along with statins Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 17 Bile Acid Sequestrants: Adverse Effects Constipation Heartburn, nausea, belching, bloating These adverse effects tend to disappear over time Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 18 Niacin (Nicotinic Acid) Vitamin B3 Lipid-lowering properties require much higher doses than when used as a vitamin Effective, inexpensive, often used in combination with other lipid-lowering drugs Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 19 Niacin: Mechanism of Action Thought to increase activity of lipase, which breaks down lipids Reduces the metabolism or catabolism of cholesterol and triglycerides Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 20 Niacin: Indications Effective in lowering triglyceride, total serum cholesterol, and LDL levels Increases HDL levels Effective in the treatment of types IIa, IIb, III, IV, and V hyperlipidemias Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 21 Niacin: Adverse Effects Flushing (caused by histamine release) Pruritus GI distress Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 22 Classroom Response Question A patient will be taking niacin as part of antilipemic therapy. The best way to avoid problems with flushing or pruritus would be to: A. take the medication at bedtime. B. take the medication with a small dose of a steroid. C. take the medication with a full glass of water on an empty stomach. D. start with a low initial dose, and then increase it gradually. Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 23 Fibric Acid Derivatives Also known as fibrates gemfibrozil (Lopid) fenofibrate (Tricor) Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 24 Fibric Acid Derivatives: Mechanism of Action Believed to work by activating lipase, which breaks down cholesterol Also suppress the release of free fatty acid from adipose tissue, inhibit synthesis of triglycerides in the liver, and increase secretion of cholesterol in the bile Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 25 Fibric Acid Derivatives: Indications Treatment of types III, IV, and V hyperlipidemias The fibric acid derivatives gemfibrozil and fenofibrate decrease the triglyceride level and increase the HDL cholesterol level by as much as 25% Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 26 Fibric Acid Derivatives: Adverse Effects Abdominal discomfort, diarrhea, nausea Blurred vision, headache Increased risk of gallstones Prolonged prothrombin time Liver studies may show increased enzyme levels Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 27 Fibric Acid Derivatives: Interactions Oral anticoagulants Statins Risk for myositis, myalgias, and rhabdomyolysis is increased Laboratory test reactions Decreased hemoglobin level, hematocrit value, and white blood cell count Increased activated clotting time, lactate dehydrogenase level, and bilirubin level Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 28 Cholesterol Absorption Inhibitor ezetimibe (Zetia) Inhibits absorption of cholesterol and related sterols from the small intestine Results in reduced total cholesterol, LDL, and triglyceride levels Also increases HDL levels Often combined with a statin drug Clinical trials continue • Currently recommended only when patients have not responded to other therapy Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 29 Herbal Product: Garlic Used as an antispasmodic, antihypertensive, antiplatelet, lipid reducer Adverse effects: dermatitis, vomiting, diarrhea, flatulence, antiplatelet activity Possible interactions with warfarin, diazepam May enhance bleeding when taken with NSAIDs Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 30 Classroom Response Question A patient wants to take garlic tablets to improve his cholesterol levels. Which condition would be a contraindication? A. Hypertension B. Bowel obstruction C. Sinus infection D. Scheduled surgery Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 31 Herbal Product: Flax Both the seed and oil of the plant are used Uses: atherosclerosis, hypercholesterolemia, GI distress, menopausal symptoms May cause diarrhea and allergic reactions Possible interactions: antidiabetic drugs, anticoagulant drugs Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 32 Herbal Product: Omega-3 Fatty Acids Fish oil products Used to reduce cholesterol May cause rash, belching, allergic reactions Potential interactions with anticoagulant drugs Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 33 Nursing Implications Before beginning therapy, obtain a thorough health and medication history Assess dietary patterns, exercise level, weight, height, vital signs, tobacco and alcohol use, family history Assess for contraindications, conditions that require cautious use, and drug interactions Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 34 Classroom Response Question Which patient would benefit from administration of simvastatin (Zocor) 80 mg? A. A patient newly diagnosed with hyperlipidemia B. A patient with muscle aches who was taking another antilipidemic drug C. A patient who is taking verapamil D. A patient who has already been taking simvastatin (Zocor) for 12 months with no evidence of myopathy Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 35 Nursing Implications (cont’d) Contraindications include biliary obstruction, liver dysfunction, active liver disease Obtain baseline liver function studies Patients on long-term therapy may need supplemental fat-soluble vitamins (A, D, K) Refer to guidelines regarding administration times and meals Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 36 Nursing Implications (cont’d) Counsel patient concerning diet and nutrition on an ongoing basis Instruct patient on proper procedure for taking the medications Powder forms must be taken with a liquid, mixed thoroughly but not stirred, and never taken dry Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 37 Nursing Implications (cont’d) 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 low initial dose and gradually increase it, and take with meals Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 38 Classroom Response Question Before administering niacin, it is most important for the nurse to assess the patient for A. allergy to erythromycin. B. gout. C. coronary artery disease. D. hypothyroidism. Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 39 Nursing Implications (cont’d) Small doses of aspirin or NSAIDs may be taken 30 minutes before niacin to minimize cutaneous flushing Provide teaching regarding use of NSAIDs and aspirin Inform patients that these drugs may take several weeks to show effectiveness Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 40 Nursing Implications (cont’d) Instruct patients to report persistent GI upset, constipation, abnormal or unusual bleeding, and yellow discoloration of the skin Monitor for adverse effects, including increased liver enzyme studies Monitor for therapeutic effects Reduced cholesterol and triglyceride levels Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 41