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Pharmacology · chapter 21 · Lipid-Lowering Drugs

Bile Acid Sequestrants, Fibrates, and Niacin

The 14 things this section of the textbook says that you are most likely to be asked about — quoted word for word, not retold. Then 6 practice questions with the reasoning.

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Key points

  1. How bile acid sequestrants lower cholesterol

    Bile acid sequestrants work by binding to bile acids in the intestine, which reduces their absorption and decreases the amount of bile acids available in the body. The body compensates for this by producing more bile acids from cholesterol, effectively decreasing the amount of cholesterol that remains.

  2. Give with meals

    These drugs are orally administered and are not absorbed into the systemic circulation; therefore, they are best taken with meals so that they will encounter the bile acids upon secretion.

  3. Adverse effects of fibrates

    Adverse effects of fibrates include increased serum transaminase, creatine phosphokinase (CPK), and creatinine levels; myopathy; cholelithiasis; and venous thrombosis.

  4. Fenofibrate forms are not interchangeable

    The various fenofibrate dosage forms are not bioequivalent and cannot be substituted for each other or for fenofibric acid on a milligram-per-milligram basis; they use different types of medication delivery technology to ensure absorption, including micronized particles, nanocrystals, and different salt forms.

  5. Gemfibrozil with statins

    The concomitant use of gemfibrozil and rosuvastatin or simvastatin is contraindicated because of the risk of myopathy and rhabdomyolysis. If the client needs to take both a fibrate and a statin, it is safer to use a fenofibric acid derivative.

  6. Gemfibrozil with warfarin

    Concomitant use with warfarin places the client at risk for bleeding, so frequent monitoring of the international normalized ratio is recommended until stabilization.

  7. The "gem" abbreviation error

    For example, gemfibrozil could be abbreviated as “gem.” This could be confused with gemcitabine, a chemotherapy agent, with severe consequences.

  8. Flush-free niacin does not work

    Some of these dietary supplements are marketed as “flush-free” niacin; however, these flush-free versions have been shown to contain no free nicotinic acid and should not be used to treat dyslipidemia (National Institutes of Health, 2022).

  9. Constipation with bile acid sequestrants

    Constipation is the most common one; it can be severe and can aggravate hemorrhoids. Clients can minimize constipation by starting doses cautiously, taking one per day.

  10. Fat-soluble vitamins and bleeding

    With long-term therapy of high doses, absorption of some fat-soluble nutrients may be decreased, and supplementation of vitamins A, D, E, and K may be needed. In extreme cases, bleeding can occur due to an induced deficiency of vitamin K, which is needed for the synthesis of clotting factors.

  11. Timing other drugs around sequestrants

    Because of this, it is recommended that clients take other drugs at least 1 hour before or 3–4 hours after taking a bile acid sequestrant (Grundy et al., 2019).

  12. Sequestrant contraindications

    Because of the high incidence of constipation, bile acid sequestrants are contraindicated in clients with a history of bowel obstruction. Because these drugs can increase triglycerides, they also are contraindicated in clients who have baseline hypertriglyceridemia or a history of pancreatitis due to hypertriglyceridemia.

  13. Niacin flushing and its cause

    The most limiting adverse effect of niacin is flushing, which is most prominent in the immediate-release preparations. This occurs because niacin increases prostaglandins in capillaries, leading to cutaneous vasodilation.

  14. Serious niacin adverse effects

    Significant adverse effects include hepatotoxicity, insulin resistance, hyperglycemia, and hyperuricemia (National Institutes of Health, 2022).

Terms to know

Bile acid sequestrants
Bile acid sequestrants are a class of drugs that lower cholesterol.
Niacin
Niacin (vitamin B 3) is a water-soluble vitamin.
lipoprotein lipase
The primary result of this activation is lower triglyceride levels via increased expression of lipoprotein lipase, an enzyme that breaks down triglycerides.

Practice questions

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Every question here, with the answer

  1. A client takes cholestyramine with breakfast and is also prescribed another oral medication each morning. How should the nurse schedule the other medication?

    1. Give it at least 1 hour before or 3–4 hours after the cholestyramine.
    2. Give it 15 minutes after the cholestyramine.
    3. Give it together with the cholestyramine so both are taken with food.
    4. Crush it and mix it into the cholestyramine powder.

    Answer: Give it at least 1 hour before or 3–4 hours after the cholestyramine.

    Bile acid sequestrants can interfere with the absorption of other drugs, so other drugs are given at least 1 hour before or 3–4 hours after. Giving them together, shortly after, or mixed in the powder exposes the drug to binding.

  2. A client taking simvastatin has a new prescription for gemfibrozil. What is the nurse's priority action?

    1. Clarify the order with the health care provider because the combination is contraindicated.
    2. Give both drugs at bedtime.
    3. Give gemfibrozil with a high-fat meal.
    4. Teach the client to report flushing.

    Answer: Clarify the order with the health care provider because the combination is contraindicated.

    Gemfibrozil with rosuvastatin or simvastatin is contraindicated because of the risk of myopathy and rhabdomyolysis; if a fibrate and a statin are both needed, a fenofibric acid derivative is safer. The other actions ignore the dangerous interaction.

  3. A nurse is teaching a client who is starting extended-release niacin. Which instructions should the nurse include? Select all that apply.

    1. Flushing means you are allergic and should stop the drug.
    2. Avoid alcoholic beverages around the time of your dose.
    3. Switch to a flush-free niacin supplement if flushing bothers you.
    4. Avoid hot drinks around the time of your dose.
    5. Ask your health care provider about taking an NSAID before your niacin.

    Answer: Avoid alcoholic beverages around the time of your dose., Avoid hot drinks around the time of your dose., Ask your health care provider about taking an NSAID before your niacin.

    Avoiding hot drinks and alcohol and taking an NSAID beforehand if directed all reduce flushing. Flush-free niacin contains no free nicotinic acid and should not be used for dyslipidemia, and flushing is an expected effect from prostaglandins, not an allergy.

  4. A client has taken high-dose colestipol for several years. Which finding should the nurse report as a possible complication of long-term therapy?

    1. Frequent urination at night
    2. Persistent dry cough
    3. Facial flushing after each dose
    4. Bleeding gums and easy bruising

    Answer: Bleeding gums and easy bruising

    Long-term high-dose therapy can reduce absorption of fat-soluble vitamins, and in extreme cases vitamin K deficiency causes bleeding. Flushing is linked to niacin, and the other findings are not described for this class.

  5. Which client conditions are contraindications to a bile acid sequestrant? Select all that apply.

    1. Baseline hypertriglyceridemia
    2. Primary hyperlipidemia
    3. History of pancreatitis due to hypertriglyceridemia
    4. History of bowel obstruction
    5. Type 2 diabetes

    Answer: Baseline hypertriglyceridemia, History of pancreatitis due to hypertriglyceridemia, History of bowel obstruction

    Sequestrants cause constipation, so bowel obstruction is a contraindication, and because they can raise triglycerides they are contraindicated in hypertriglyceridemia or pancreatitis from it. Colesevelam is even approved for blood sugar reduction in type 2 diabetes, and primary hyperlipidemia is what these drugs treat.

  6. A client taking fenofibrate is also started on a statin. Which assessment is most important for the nurse to monitor?

    1. Muscle pain or weakness
    2. Facial flushing
    3. Dry mouth
    4. Hair loss

    Answer: Muscle pain or weakness

    Myopathy is a common adverse effect of fibrates, especially when combined with statins, so the nurse monitors for muscle-related adverse effects. Flushing belongs to niacin, and the other findings are not described in the section.

Where every quote comes from

Section 21.3 Bile Acid Sequestrants, Fibrates, and Niacin of Pharmacology for Nurses by Tina Barbour-Taylor, Leah Mueller (Sabato), Donna Paris, Dorie Weaver, OpenStax, 2024. Read the whole section free at openstax.org.

The textbook is licensed under CC BY-NC-SA 4.0. This page quotes it word for word and adds the headings, the order and the practice questions; references to the book's figures and stray spaces left by its formatting are removed. The page is shared under the same licence. Nothing here is sold.