Medications Affecting Urinary Output, Antianginal and Lipid-Lowering Agents

Furosemide (Lasix)

• Class and Group: High-ceiling loop diuretic; prototype medication affecting urinary output.

• Pharmacological Action: Blocks the $\text{Na}^+-\text{K}^+-2\text{Cl}^-$ transporter in the thick ascending loop of Henle. This results in the excretion of large amounts of sodium ($\text{Na}^+$), chloride ($\text{Cl}^-$), and water ($\text{H}_2\text{O}$). It also increases the loss of potassium ($\text{K}^+$), magnesium ($\text{Mg}^{2+}$), and calcium ($\text{Ca}^{2+}$).

• Indications (Why we give it):

  • Edema associated with heart failure, kidney disease, or liver disease.

  • Selected cases of hypertension.

  • Intravenous (IV) administration is used to rapidly reduce pulmonary congestion.

  • Utilized when a strong, immediate diuretic effect is required.

• Main Test Idea: A powerful diuretic that removes sodium and water; necessitates monitoring for low potassium, dehydration, kidney injury, hypotension, and ototoxicity.

• Common Side Effects:

  • Frequent urination and thirst.

  • Dizziness and orthostatic hypotension occurring as blood volume decreases.

  • Muscle cramps or weakness due to low levels of potassium, sodium, and magnesium.

  • Potential elevations in blood glucose and uric acid levels.

• Serious Adverse Reactions:

  • Severe dehydration or electrolyte loss leading to kidney injury, shock, or cardiac dysrhythmias.

  • Ototoxicity, characterized by tinnitus or hearing loss, particularly with rapid IV administration or concurrent use of other ototoxic drugs.

  • Potential for severe skin reactions or sulfonamide-type hypersensitivity.

• Nursing and ATI Focus:

  • Monitor blood pressure, daily weight, intake/output, lung sounds, and edema.

  • Track electrolytes, BUN, and creatinine levels.

  • Medication should be administered in the morning.

  • IV doses must be administered at the recommended rate to mitigate the risk of ototoxicity.

  • Instruct patients on the intake of potassium-rich foods or supplements only as specifically ordered.

  • Advise reporting of hearing changes, severe weakness, fainting, muscle cramps, or significantly reduced urine output.

• Professor Exam Blueprint Note: Identified as the high-ceiling loop-diuretic prototype.

Spironolactone (Aldactone)

• Class and Group: Aldosterone antagonist; potassium-sparing diuretic; medication affecting urinary output and heart failure.

• Pharmacological Action: Competitively blocks aldosterone receptors in the distal nephron. This action causes sodium and water to be excreted while potassium is retained. Additionally, aldosterone blockade reduces cardiac fibrosis and remodeling.

• Indications (Why we give it):

  • Heart failure, hypertension, edema, and ascites.

  • Treatment of hyperaldosteronism.

  • Shown to improve survival in selected patients with heart failure.

  • Useful when excess aldosterone contributes to sodium and water retention.

• Main Test Idea: Removes sodium and water but retains potassium; necessitates monitoring for hyperkalemia, renal injury, and endocrine effects such as gynecomastia.

• Common Side Effects:

  • Hyperkalemia resulting from potassium retention.

  • Endocrine effects because the drug interacts with steroid receptors, leading to gynecomastia, breast tenderness, menstrual changes, or sexual dysfunction.

  • Dizziness, gastrointestinal (GI) upset, or mild dehydration.

• Serious Adverse Reactions:

  • Severe hyperkalemia (high potassium), which can lead to paralysis or fatal dysrhythmias.

  • Acute kidney injury, potentially causing potassium and drug accumulation.

  • Severe dehydration or hypotension leading to reduced organ perfusion.

• Nursing and ATI Focus:

  • Monitor potassium levels, renal function, blood pressure, weight, edema, and intake/output.

  • Patients should avoid potassium supplements, potassium-based salt substitutes, and excessive intake of high-potassium foods unless prescribed.

  • Exercise caution when used with ACE inhibitors, ARBs, ARNIs, NSAIDs, and other drugs that raise potassium levels.

  • Instruct patients to report muscle weakness, tingling sensations, heart palpitations, fainting, or reduced urine output.

• Professor Exam Blueprint Note: Identified as the potassium-sparing-diuretic prototype.

Mannitol (Osmitrol)

• Class and Group: Osmotic diuretic; medication affecting urinary output.

• Pharmacological Action: Increases plasma and renal-tubule osmotic pressure, causing water to move from tissues into the bloodstream to be filtered into the urine. Dehydration occurs after an initial period of blood-volume expansion.

• Indications (Why we give it):

  • Reduction of intracranial pressure (ICP) or intraocular pressure (IOP).

  • Promotion of urine flow in specific clinical situations.

  • Indicated when water must be shifted rapidly out of brain or eye tissue.

• Main Test Idea: Pulls water from swollen tissue into the bloodstream and kemudian the urine; necessitating surveillance for pulmonary edema, heart failure, dehydration, electrolyte shifts, and renal function.

• Common Side Effects:

  • Headache, nausea, thirst, chills, or dizziness during the infusion.

  • Large urine output resulting in dehydration and electrolyte imbalances.

  • Temporary volume expansion that can increase blood pressure or cardiac workload.

• Serious Adverse Reactions:

  • Pulmonary edema or worsening heart failure caused by the initial movement of water into the bloodstream.

  • Severe dehydration, electrolyte imbalance, or kidney injury if diuresis is excessive or if the kidneys cannot excrete the medication.

  • Rebound intracranial pressure if the drug accumulates or if therapy is prolonged.

• Nursing and ATI Focus:

  • Assess lung sounds, oxygenation, edema, and heart-failure status.

  • Monitor neurological findings, urine output, electrolytes, renal function, and serum osmolality.

  • Solution must be inspected for crystals; use the required filter and warming procedures per facility policy.

  • Discontinue use and notify the provider if pulmonary edema, worsening shortness of breath, or inadequate urine output develops.

  • Use with extreme caution or avoid in cases of anuria, severe dehydration, or active pulmonary congestion.

• Professor Exam Blueprint Note: Identified as the osmotic-diuretic prototype.

Nitroglycerin (Nitrostat / Nitro-Dur)

• Class and Group: Organic nitrate; vasodilator; antianginal agent.

• Pharmacological Action: Converted to nitric oxide ($\text{NO}$), which increases cyclic GMP ($\text{cGMP}$) in vascular smooth muscle. Venodilation occurs more significantly than arterial dilation, which reduces venous return and preload. Coronary dilation and lower wall tension enhance the oxygen supply-demand balance.

• Indications (Why we give it):

  • Prevention and relief of angina episodes.

  • Used in selected acute coronary syndromes or heart-failure situations.

  • Reduces the overall workload and oxygen demand of the heart.

  • Sublingual forms provide rapid relief for acute angina attacks.

• Main Test Idea: Venodilation lowers preload and heart oxygen demand; headache and hypotension are common. Use with PDE-5 inhibitors can cause fatal hypotension.

• Common Side Effects:

  • Throbbing headache and flushing due to vasodilation.

  • Dizziness and orthostatic hypotension, specifically with initial doses.

  • Reflex tachycardia or palpitations as blood pressure falls.

• Serious Adverse Reactions:

  • Profound hypotension, syncope, ischemia, or shock.

  • Life-threatening hypotension when combined with PDE-5 inhibitors (e.g., sildenafil) or riociguat.

  • Rare occurrence of methemoglobinemia, which impairs oxygen delivery.

• Nursing and ATI Focus:

  • For sublingual use: The patient should sit or lie down. If pain persists after the first dose, follow the emergency plan and call EMS promptly.

  • Check blood pressure and pain response before and after administration.

  • Contraindicated with recent PDE-5 inhibitor use.

  • Transdermal administration: Remove old patches before applying new ones, rotate application sites, and wear gloves to prevent self-absorption.

  • Ensure a daily nitrate-free interval for long-acting preparations to minimize the development of drug tolerance.

• Professor Exam Blueprint Note: Identified as the organic-nitrate prototype.

Ranolazine (Ranexa)

• Class and Group: Late sodium-current inhibitor; antianginal medication.

• Pharmacological Action: Inhibits the late inward sodium current ($\text{late } \text{I}_{\text{Na}}$) in cardiac cells. Reducing intracellular sodium ($\text{Na}^+$) prevents calcium ($\text{Ca}^{2+}$) overload, allowing the heart to relax more effectively during diastole and use oxygen more efficiently.

• Indications (Why we give it):

  • Chronic angina treatment when other therapies are insufficient or not tolerated.

  • Improves exercise tolerance and reduces the frequency of angina episodes.

  • Note: Not indicated for stopping an acute angina attack.

• Main Test Idea: Treats chronic angina without significantly lowering heart rate or blood pressure; monitor for QT prolongation, renal/liver issues, and interactions with CYP3A.

• Common Side Effects:

  • Dizziness, headache, constipation, and nausea.

  • Weakness or lightheadedness, particularly during dose adjustment.

  • Drug levels significantly increase if metabolic pathways are inhibited.

• Serious Adverse Reactions:

  • Dose-related QT prolongation, which can lead to dangerous cardiac dysrhythmias in high-risk patients.

  • Risk of acute kidney injury, especially in patients with existing severe renal impairment.

  • Toxic or ineffective drug levels when taken with strong CYP3A inhibitors or inducers.

• Nursing and ATI Focus:

  • Monitor angina patterns, ECG for QT interval, renal function, and liver history.

  • Extended-release tablets must be swallowed whole; do not crush, split, or chew.

  • Avoid grapefruit and grapefruit juice.

  • Review all medications for potential QT-prolonging or CYP3A interactions.

  • Patients should maintain access to rapid-acting nitrates for acute angina episodes.

• Professor Exam Blueprint Note: Identified as the antianginal prototype separate from organic nitrates.

Atorvastatin (Lipitor)

• Class and Group: Statin; HMG-CoA reductase inhibitor; lipid-lowering agent.

• Pharmacological Action: Competitively inhibits HMG-CoA reductase, the rate-limiting liver enzyme in cholesterol production. This triggers the liver to produce more LDL receptors, which increases the removal of LDL cholesterol from the bloodstream. It also stabilizes plaque and reduces inflammation.

• Indications (Why we give it):

  • Lowering LDL cholesterol.

  • Prevention of cardiovascular events.

  • First-line therapy for atherosclerotic cardiovascular risk.

• Main Test Idea: Strongly lowers LDL and cardiovascular risk; monitor for muscle injury, liver injury, drug interactions, and pregnancy.

• Common Side Effects:

  • Mild muscle aches ($\text{myalgia}$), headache, or GI upset.

  • Asymptomatic elevations in liver enzymes.

  • Slight potential for increased blood glucose levels.

• Serious Adverse Reactions:

  • Myopathy or rhabdomyolysis, characterized by severe muscle weakness, kidney injury, and dark (tea-colored) urine.

  • Clinically significant liver injury (rare).

  • Increased risk of muscle toxicity when blood levels are raised due to drug interactions.

• Nursing and ATI Focus:

  • Obtain baseline lipid profiles and monitor response; assess liver function tests (LFTs) as indicated.

  • Patients must immediately report unexplained muscle pain, weakness, fever, or dark urine.

  • Pregnancy is a contraindication.

  • Review all medications and grapefruit intake with the prescriber.

  • Emphasize adherence to diet, physical activity, and smoking cessation.

• Professor Exam Blueprint Note: Identified as the HMG-CoA reductase inhibitor (statin) prototype.

Ezetimibe (Zetia)

• Class and Group: Intestinal cholesterol absorption inhibitor; lipid-lowering agent.

• Pharmacological Action: Blocks the NPC1L1 transporter located at the intestinal brush border. This decreases the absorption of dietary and biliary cholesterol, leading the liver to increase uptake of LDL from the blood.

• Indications (Why we give it):

  • Lowering LDL when a statin alone is insufficient or not tolerated.

  • Can be used as monotherapy or in combination with a statin.

  • Reduces the volume of cholesterol delivered from the intestine to the liver.

• Main Test Idea: Blocks cholesterol absorption in the intestine; effects are usually mild alone, but risks to the liver and muscles increase when combined with a statin.

• Common Side Effects:

  • Diarrhea, abdominal discomfort, fatigue, or headache.

  • Mild muscle aches.

  • Increased likelihood of liver-enzyme elevations when combined with statins.

• Serious Adverse Reactions:

  • Rare risk of myopathy or rhabdomyolysis, especially if used with a statin.

  • Serious liver injury (uncommon).

  • Potential for hypersensitivity reactions.

• Nursing and ATI Focus:

  • Monitor lipid response and assess liver function when used in combination with a statin.

  • Instruct patients to report unexplained muscle pain, weakness, dark urine, jaundice, or severe abdominal pain.

  • Dosing relative to other meds: Administer at least 2 hours before or 4 hours after a bile-acid sequestrant.

  • Medication does not replace the need for lifestyle modifications like heart-healthy diet and exercise.

• Professor Exam Blueprint Note: Identified as the cholesterol-absorption-inhibitor prototype.

Colesevelam (Welchol)

• Class and Group: Bile-acid sequestrant; lipid-lowering agent.

• Pharmacological Action: Binds bile acids in the intestine, preventing their reabsorption. The liver responds by using internal cholesterol to synthesize replacement bile acids. This process increases the production of LDL receptors, which clears LDL from the blood.

• Indications (Why we give it):

  • Lowering LDL cholesterol.

  • Improving glycemic control in patients with type 2 diabetes.

  • Indicated when a non-systemic lipid-lowering option is preferred.

  • Can be used in conjunction with statins.

• Main Test Idea: Remains in the GI tract to bind bile acids; monitor for constipation, elevated triglycerides, bowel obstruction, and interference with the absorption of other drugs or vitamins.

• Common Side Effects:

  • Constipation, bloating, nausea, and dyspepsia due to the drug staying in the gut.

  • Physical difficulty in swallowing large tablets or powder.

  • Risk of rising triglyceride levels.

• Serious Adverse Reactions:

  • Bowel obstruction in patients with impaired GI motility.

  • Pancreatitis triggered by marked triglyceride elevation.

  • Malabsorption of fat-soluble vitamins ($\text{A, D, E, K}$) and other medications due to binding in the gut.

• Nursing and ATI Focus:

  • Assess bowel habits, baseline triglycerides, and current medication timing.

  • Encourage high fluid intake, fiber consumption, and physical activity.

  • Take with meals and sufficient liquid; mix powder forms exactly as directed.

  • Space interacting vitamins or medications from the dose by the recommended interval, usually at least 4 hours.

• Professor Exam Blueprint Note: Identified as the bile-acid-sequestrant prototype.

Alirocumab (Praluent)

• Class and Group: PCSK9 inhibitor; monoclonal antibody; lipid-lowering agent.

• Pharmacological Action: Binds to circulating PCSK9, preventing it from destroying LDL receptors on the surface of liver cells. By preserving these receptors, more LDL is cleared from the blood.

• Indications (Why we give it):

  • Used for patients requiring extra LDL reduction, including those with familial hypercholesterolemia or established cardiovascular disease.

  • Frequently added to the maximally tolerated statin dose.

  • Provides substantial LDL reduction when oral therapies are insufficient.

• Main Test Idea: A subcutaneous biologic that significantly lowers LDL by preserving liver LDL receptors; track for injection site reactions and hypersensitivity.

• Common Side Effects:

  • Injection-site reactions: redness, itching, pain, or swelling.

  • Nasopharyngitis or symptoms resembling the flu.

  • Mild muscle symptoms.

• Serious Adverse Reactions:

  • Serious hypersensitivity reactions, including angioedema.

  • Persistent or severe injection reactions necessitating medical evaluation.

  • Potential for very low LDL levels, requiring clinical follow-up.

• Nursing and ATI Focus:

  • Provide education on subcutaneous injection technique, site rotation, storage (refrigeration), and the use of sharps containers for disposal.

  • Allow the injection device to reach room temperature before use; instructed not to shake the medication.

  • Monitor lipid levels following the start of therapy and any dose adjustments.

  • Patients should continue their prescribed statins and lifestyle changes unless otherwise directed by their provider.

• Professor Exam Blueprint Note: Identified as the monoclonal-antibody lipid-lowering prototype.