Antilipemic Drugs,Thyroid and Antithyroid Drugs, Women’s Health Drugs

Chapter 16: Antilipemic Drugs

Overview

  • Pages Covered: 430-444

Cholesterol Homeostasis

  • Importance of Cholesterol in the Body:

    • Helps in cell formation.

    • Synthesis of hormones, bile acids, and vitamin D.

  • Sources of Cholesterol:

    • Food: Dietary intake.

    • Endogenous: Produced by the body itself.

Blood Transport of Cholesterol (Lipoproteins)

  • Types of Lipoproteins and Their Functions:

    • Chylomicrons: Deliver lipids to tissues.

    • VLDL (Very Low-Density Lipoprotein): Transported from liver.

    • LDL (Low-Density Lipoprotein): Known as "bad cholesterol"; contributes to plaque buildup in arteries.

    • HDL (High-Density Lipoprotein): Known as "good cholesterol"; helps remove cholesterol from the bloodstream.

  • Factors Influencing Cholesterol Balance in the Body:

    • Dietary intake and hepatic (liver) production.

    • Hormonal influences on lipid metabolism.

    • Feedback loops that regulate cholesterol levels.

  • System-Level Control:

    • Mechanisms by which cells control cholesterol elimination.

Hyperlipidemias and Treatment Guidelines

  • Definition of Hyperlipidemia:

    • Condition characterized by elevated blood lipids.

  • When Should Treatment Be Considered?

    • Overall assessment: Consider the whole patient and lifestyle factors.

    • Lifestyle Changes: First line of treatment.

    • Medications: Initiated if lifestyle changes are insufficient.

  • Guiding Sources:

    • Guidelines may consider the connection to metabolic syndrome.

    • Importance of regular monitoring and follow-up.

HMG-COA Reductase Inhibitors (Statins)

  • Overview of Statins:

    • Most common class of drugs used to treat hyperlipidemia.

  • Examples:

    • Atorvastatin (Lipitor): Widely used, long-acting statin.

    • Simvastatin (Zocor): Commonly prescribed, shorter-acting statin.

  • Mechanism of Action:

    • Inhibit HMG-COA reductase, resulting in increased LDL receptors that pull LDL cholesterol from the bloodstream.

  • Drug Effects:

    • Lower LDL cholesterol, total cholesterol, and triglycerides.

    • Higher HDL cholesterol levels.

  • Indications for Use:

    • Primarily used to treat primary hypercholesterolemia.

  • Contraindications:

    • Active liver disease.

    • Pregnancy.

  • Common Side Effects:

    • Myalgia (muscle pain).

    • Mild gastrointestinal (GI) upset.

  • Adverse Effects:

    • Myopathy and rhabdomyolysis.

    • Hepatotoxicity: if it occurs, the drug should be stopped, hydration initiated, and kidney function as well as liver enzymes monitored.

  • Drug Interactions:

    • CYP3A4 inhibitors such as some antifungals and macrolide antibiotics.

  • Nursing Considerations and Patient Teaching:

    • Obtain baseline liver function tests (LFTs).

    • Emphasize lifestyle changes alongside medication.

    • Advise taking medication at the same time every day (usually evening).

    • Avoid grapefruit juice due to interaction with statins.

Bile Acid Sequestrants

  • Common Drugs:

    • Cholestyramine (Questran)

    • Colestipol (Colestid)

    • Colesevelam (Welchol): Newer and often better tolerated.

  • Mechanism of Action:

    • Binds to bile acids in the intestine, causing the liver to utilize more cholesterol to synthesize new bile acids.

  • Drug Effects:

    • Lower LDL cholesterol and raise HDL cholesterol.

  • Indications for Use:

    • Primarily used for primary hypercholesterolemia.

  • Contraindications:

    • Bowel obstruction.

    • Triglycerides above 400 mg/dL.

  • Side Effects:

    • Gastrointestinal symptoms.

    • Vitamin deficiencies due to malabsorption.

  • Adverse Effects:

    • Rare instances of bowel obstruction.

  • Drug Interactions:

    • Interference with the absorption of other medications such as warfarin, digoxin, and fat-soluble vitamins (A, D, E, K).

  • Nursing Considerations and Patient Teaching:

    • Encourage taking with plenty of fluids.

    • Instruct patients to take other medications 1 hour before or 4 hours after bile acid sequestrant administration.

    • Recommend a high fiber diet.

    • Advise against swallowing the powder dry.

Niacin (Vitamin B3)

  • Mechanism of Action:

    • Inhibits hepatic synthesis of VLDL, resulting in decreased LDL production.

    • Decreases clearance of HDL, which raises HDL levels.

  • Drug Effects:

    • Lowers LDL and triglycerides, raises HDL.

  • Indication for Use:

    • Primary hyperlipidemia.

  • Contraindications:

    • Liver disease.

    • Peptic ulcer disease.

    • Gout.

  • Common Side Effects:

    • Flushing (most frequent side effect).

    • Gastrointestinal upset.

  • Adverse Effects:

    • Hepatotoxicity.

    • Hyperuricemia.

  • Drug Interactions:

    • Other lipid-lowering medications.

    • Antihypertensive drugs.

  • Nursing Considerations and Patient Teaching:

    • Educate patients to expect flushing and to consider taking aspirin (ASA) beforehand.

    • Advise against hot drinks or alcohol consumption.

    • Monitor liver function tests (LFTs).

    • Encourage lifestyle modifications.

Fibric Acid Derivatives (Fibrates)

  • Most Common Drugs:

    • Gemfibrozil (Lopid)

    • Fenofibrate (Tricor)

  • Mechanism of Action:

    • Increases lipoprotein lipase activity, enhancing the breakdown of triglyceride-rich lipoproteins.

  • Drug Effects:

    • Lowers triglycerides as the primary effect, lowers LDL, and modestly raises HDL.

  • Indications for Use:

    • Severe hypertriglyceridemia.

  • Contraindications:

    • Severe liver and kidney disease.

  • Common Side Effects:

    • Gastrointestinal upset.

    • Rash and headache.

  • Adverse Effects:

    • Myopathy and rhabdomyolysis, especially when used with statins.

    • Hepatotoxicity and gallstones (cholelithiasis).

  • Drug Interactions:

    • Caution when combined with statins, anticoagulants, and bile acid sequestrants.

  • Nursing Considerations and Patient Teaching:

    • Assess liver function tests (LFTs) and kidney function.

    • Monitor for gallbladder disease.

    • Take fibrates with meals for better absorption.

    • Patients may need additional medications (like a statin) alongside fibrates.

    • Encourage lifestyle changes.

Miscellaneous Antilipemic Drugs

  • Cholesterol Absorption Inhibitor:

    • Ezetimibe (Zetia): Blocks the absorption of cholesterol in the small intestine, leading to lower LDL levels.

    • Side Effects: GI-related.

  • PCKSK9 Inhibitors:

    • Alirocumab (Praluent) and Evolcumab (Repatha): Block PCSK9, increasing LDL receptor availability which improves cholesterol clearance from the blood.

    • Indication: For patients who do not respond satisfactorily to statins and ezetimibe.

    • Side Effects: Related to injection-site reactions.

    • Challenges: Costly and may require prior authorization for coverage.

    • Nursing Considerations and Patient Teaching:

    • Regular lipid panel monitoring.

    • Discuss cost and access to medications.

    • Encourage lifestyle changes.

Chapter 22: Thyroid and Antithyroid Drugs

Overview

  • Pages Covered: 407-419

Thyroid Hormone Regulation

  • Controlled by: The hypothalamus.

  • Key Hormones in Regulation:

    • TSH (Thyroid-Stimulating Hormone)

    • T3 (Triiodothyronine)

    • T4 (Thyroxine)

  • Thyroid Antibodies:

    • Indicators of autoimmune thyroid disease.

  • Lab Tests for Thyroid Function:

    • Ultrasound and imaging studies.

    • Radioactive iodine uptake scan for diagnosis.

Thyroid Disorders

  • Hypothyroidism:

    • Definition: Insufficient production of thyroid hormones.

    • Common Cause: Hashimoto's disease.

    • Symptoms: Fatigue, weight gain, feeling cold, hair loss and brittle nails, bradycardia.

    • Complications: Myxedema, a life-threatening condition.

  • Hyperthyroidism:

    • Definition: Excessive production of thyroid hormones.

    • Common Cause: Graves’ disease.

    • Symptoms: Weight loss, heat intolerance, anxiety, insomnia.

    • Complications: Thyroid storm, a severe, acute exacerbation of symptoms.

Levothyroxine (Synthroid and Levoxyl)

  • Indication: Treatment of hypothyroidism.

  • Mechanism of Action:

    • Replaces T4, which is converted to active T3, thus restoring normal metabolic activity.

  • Common Side Effects:

    • Nervousness, weight loss, gastrointestinal symptoms, mild heat intolerance or sweating.

  • Adverse Effects:

    • Hypertension, arrhythmias, osteoporosis, potential for thyroid storm due to overmedication.

  • Drug Interactions:

    • Decreased absorption with calcium supplements, antacids, and bile acid sequestrants.

    • Increased metabolism with rifampin and phenobarbital.

    • Enhances effects and toxicity of warfarin and sympathomimetics (such as adrenalines).

    • Food factors: Soy, high-fiber foods, and grapefruit juice can interfere with absorption.

  • Nursing Considerations and Patient Teaching:

    • Take on an empty stomach and wait 30-60 minutes before consuming other medications.

    • Schedule laboratory tests every 6-8 weeks until thyroid levels stabilize.

    • Emphasize the importance of consistent medication adherence.

Antithyroid Agents: Propylthiouracil (PTU)

  • Mechanism of Action:

    • Blocks synthesis of thyroid hormones.

    • Inhibits conversion of T4 to T3.

  • Indications:

    • Treatment of Graves’ disease and thyroid storm.

  • Common Side Effects:

    • Rash, itching, mild gastrointestinal upset.

  • Adverse Effects:

    • Hepatotoxicity and agranulocytosis (dangerously low white blood cell count).

  • Drug Interactions:

    • Caution with warfarin and other antithyroid or bone marrow-suppressing medications.

  • Nursing Considerations and Patient Teaching:

    • Regular lab monitoring for thyroid function and blood counts.

    • Take regularly at consistent intervals throughout the day (2-3 times daily).

    • Not recommended for long-term use during pregnancy due to potential harms to the fetus.

Radioactive Iodine (I-131)

  • Indication: Definitive treatment of hyperthyroidism.

  • Mechanism of Action:

    • Absorbed by thyroid gland where it selectively destroys thyroid tissue.

  • Long-term Effects:

    • Results in lifelong requirement for thyroid hormone replacement.

  • Administration: Given orally.

  • Common Side Effects:

    • Soreness in the neck, gastrointestinal symptoms.

  • Long-term Complications:

    • May lead to hypothyroidism.

  • Nursing Considerations and Patient Teaching:

    • Importance of radiation safety practices following treatment.

    • Advise patients to avoid close contact with children and pregnant women.

    • Suggest avoiding sharing utensils, using separate bathrooms, and sleeping separately after treatment.

Chapter 29: Women's Health Drugs

Overview

  • Pages Covered: 520-533

Menopause

  • Stages of Menopause:

    • Premenopause: Cycles remain regular.

    • Perimenopause: Hormone levels fluctuate, leading to irregular cycles.

    • Menopause: Defined as 12 months without a cycle.

    • Postmenopause: Symptoms may lessen, but long-term health risks can increase.

Hormone Replacement Therapy (HRT)

  • Intended Responses of HRT:

    • Primary goal is relief of menopausal symptoms.

  • Contraindications:

    • History of breast or uterine cancer.

    • History of blood clots or liver disease.

  • Common Side Effects:

    • Breast tenderness and nausea.

  • Adverse Effects:

    • Increased risk of blood clots (such as stroke and myocardial infarction).

    • Higher risks for certain cancers.

  • Nursing Considerations and Patient Teaching:

    • Obtain thorough health history.

    • Assess vital signs (VS) and encourage self-examinations.

    • Instruct on lifestyle measures to minimize side effects and risks.

Specific Medications for Menopause

  • Estrogen:

    • Used alone or in combination; effective in relieving vasomotor symptoms.

  • Risks Associated with Estrogen:

    • Blood clot risks, stroke risks, and specific cancer risks (notably endometrial cancer).

  • Progesterone:

    • Administered with estrogen to lessen the risk of endometrial cancer.

  • Non-Hormonal Options:

    • Paroxetine (Brisdelle): Approved FDA option for alleviating vasomotor symptoms, with risks of neuroleptic malignant syndrome and serotonin syndrome.

Oral Contraceptives

  • Variety and Availability:

    • Over 300 brands available, in various forms.

  • Adverse Effects:

    • Similar to HRT risks. Continuous monitoring needed.

  • Nursing Considerations and Patient Teaching:

    • Suggested use of alternative birth control during the first month.

    • Advise patients to take at the same time each day and provide instructions for missed doses.

    • Caution advised for pediatric use; contraindicated in pregnancy and breastfeeding.

Osteoporosis Drugs

  • Classes of Osteoporosis Drugs:

    • Bisphosphonates (first-line): Prevent bone breakdown (e.g., Alendronate [Fosamax]).

    • SERMs (Selective Estrogen Receptor Modulators): Useful for women at risk for breast cancer (e.g., Raloxifene [Evista]).

    • PTH Analogues: Build new bone, reserved for severe cases (e.g., Teriparatide [Forteo]).

    • Denosumab (Prolia): Injection, a strong antiresorptive option for osteoporosis.

    • Calcitonin (Miacalcin): Weaker option, used less frequently in current practice.

Fertility Drugs and Uterine Stimulants

  • Fertility Drugs:

    • Clomiphene Citrate (Clomid): First line treatment for infertility; works by blocking estrogen receptors in the hypothalamus.

    • Gonadotropins: Utilized when Clomiphene is ineffective, directly stimulates the ovaries.

  • Uterine Stimulants:

    • Oxytocin (Pitocin): Stimulates uterine contractions during labor.

    • Prostaglandins (dinoprostone): Induce cervical ripening.

    • Ergot Alkaloids (Methergine): Cause strong and sustained uterine contractions.