Medications Affecting Blood Pressure Flashcards
Hydrochlorothiazide (Microzide)
Class / Group: Thiazide diuretic; also classified as a medication affecting urinary output.
Prototype / AKA: Hydrochlorothiazide (HCTZ).
General Clinical Use:
First-line drug for the treatment of hypertension.
Used to treat mild edema.
Reduces long-term risk of stroke and heart-related complications by lowering blood pressure.
Preferred due to its effectiveness, affordability, and ease of oral administration.
Mechanism of Action:
Binds to and blocks the reabsorption of sodium and chloride in the distal convoluted tubule of the nephron.
Promotes diuresis since water follows sodium into the urine, resulting in reduced circulating blood volume.
Long-term use decreases resistance within the blood vessels (vasodilation effect).
Side Effects and Rationales:
Frequent Urination: Occurs as the drug forces more water and sodium out of the body.
Dizziness and Orthostatic Hypotension: Result from the decrease in total circulating blood volume.
Electrolyte/Metabolic Changes: Renal electrolyte alterations can lead to low potassium (hypokalemia), low sodium (hyponatremia), elevated glucose (hyperglycemia), and elevated uric acid.
Serious Adverse Reactions:
Severe Dehydration: Can lead to weakness, confusion, and falls.
Hypokalemia: Increases the risk of dangerous ventricular dysrhythmias and toxicity from medications like digoxin.
Hypersensitivity: Includes rare but serious skin reactions, pancreatitis, or sulfonamide-type allergies.
Potassium Thresholds (South College Medical Center):
Normal range: .
Hypokalemia threshold: Any value below .
Patient symptoms of low potassium: Leg cramps, muscle spasms, arrhythmias, and dysrhythmias.
Nursing and Patient Education:
Monitor blood pressure, daily weight, intake/output (I/O), and renal function.
Track laboratory values for sodium, potassium, glucose, and uric acid.
Administer the medication in the morning; if a second dose is needed, give it early in the afternoon to prevent nocturia.
Teach patients to rise slowly from sitting or lying down.
Discuss potassium-rich foods unless the patient is on a potassium restriction.
Advise patients to report muscle cramps, spasms, severe weakness, confusion, fainting, or irregular heartbeats to their provider.
Captopril (Capoten)
Class / Group: Angiotensin-converting enzyme (ACE) inhibitor.
Prototype / AKA: Captopril.
General Clinical Use:
Treatment of hypertension and heart failure.
Used for post-myocardial injury protection in specific patients.
Provides nephroprotection in patients with diabetic kidney disease by reducing pressure within the kidneys.
Reduces the workload of the heart by lowering afterload.
Mechanism of Action:
Blocks the angiotensin-converting enzyme, preventing the conversion of angiotensin I into angiotensin II.
Lower levels of angiotensin II result in systemic vasodilation.
Decreases aldosterone secretion, leading to less sodium and water retention.
Increases levels of bradykinin, which aids vasodilation but is also the secondary cause of a dry cough.
Side Effects and Rationales:
Dry, Persistent Cough: Caused by the accumulation of bradykinin.
First-dose Hypotension: Blood vessels relax significantly upon initiation of therapy.
Hyperkalemia: Potassium levels rise because the reduction in aldosterone inhibits potassium excretion.
Taste Changes and Rash: Specific side effects associated with captopril.
Serious Adverse Reactions:
Angioedema: Rapid swelling of the face, lips, tongue, or airway; this is a medical emergency.
Acute Kidney Injury (AKI): Especially a risk for patients with renal artery stenosis or those who are dehydrated.
Fetal Toxicity: ACE inhibitors can cause severe harm or death to a developing fetus and are contraindicated in pregnancy.
Nursing and Patient Education:
Check blood pressure, potassium, BUN, and creatinine levels before and during therapy.
Instruct patients to avoid potassium supplements and potassium-based salt substitutes.
Administer on an empty stomach to ensure optimal absorption (food reduces drug uptake).
Report any facial swelling, difficulty breathing, fainting, decreased urine output, or severe weakness immediately.
Losartan (Cozaar)
Class / Group: Angiotensin II receptor blocker (ARB).
Prototype / AKA: Losartan.
General Clinical Use:
Management of hypertension and diabetic kidney disease.
Reduction of stroke risk in hypertensive patients with left-ventricular hypertrophy.
Alternative for patients who cannot tolerate the dry cough caused by ACE inhibitors.
Mechanism of Action:
Blocks angiotensin II from binding to AT1 receptors in the blood vessels and adrenal glands.
Induces blood vessel relaxation and decreases aldosterone release.
Reduces sodium and water retention while potentially increasing potassium levels.
Side Effects and Rationales:
Dizziness and Orthostatic Hypotension: Linked to the drop in systemic blood pressure.
Hyperkalemia: Occurs as a result of suppressed aldosterone activity.
Elevated Kidney Function Tests: BUN and creatinine may rise, particularly in dehydrated patients or those with renal artery stenosis.
Serious Adverse Reactions:
Angioedema: While less frequent than with ACE inhibitors, it remains a threat to the airway.
Acute Kidney Injury: Risk of severe renal impairment.
Fetal Injury: Contraindicated during pregnancy due to the risk of fetal death.
Nursing and Patient Education:
Monitor blood pressure, potassium, and renal labs (BUN/Creatinine).
Instruct patients to avoid potassium supplements and salt substitutes containing potassium.
Verify pregnancy plans; if a patient becomes pregnant, the drug must be stopped and the provider notified.
Advise patients to report swelling of the face, palpitations, reduced urine output, or breathing difficulties.
Aliskiren (Tekturna)
Class / Group: Direct renin inhibitor.
Prototype / AKA: Aliskiren.
General Clinical Use:
Lowering blood pressure in hypertension.
Acts earlier in the Renin-Angiotensin-Aldosterone System (RAAS) than ACE inhibitors or ARBs to reduce cardiovascular risk.
Mechanism of Action:
Directly inhibits the enzyme renin, preventing the conversion of angiotensinogen to angiotensin I.
Consequently suppresses the activity of both angiotensin II and aldosterone.
Promotes vessel relaxation and sodium/water excretion by the kidneys.
Side Effects and Rationales:
Diarrhea: A common gastrointestinal side effect specific to this drug.
Dizziness and Hypotension: Standard effects of blood pressure reduction.
Elevated Potassium and Creatinine: Occurs due to RAAS suppression.
Serious Adverse Reactions:
Angioedema: May lead to airway obstruction.
Severe Hyperkalemia and Kidney Injury: Can lead to cardiac dysrhythmias and organ damage.
Combination Contraindication: Must never be combined with an ACE inhibitor or ARB in patients with diabetes due to the high risk of complications.
Nursing and Patient Education:
Monitor blood pressure, potassium, BUN, and creatinine.
Maintain consistency regarding meals; high-fat meals significantly reduce the absorption of the drug.
Report pregnancy immediately; report facial swelling, severe diarrhea, or low urine output.
Nifedipine (Procardia XL)
Class / Group: Dihydropyridine calcium channel blocker (CCB).
Prototype / AKA: Nifedipine.
General Clinical Use:
Hypertension and chronic angina.
Primarily used when the therapeutic goal is arterial relaxation and afterload reduction.
Mechanism of Action:
Blocks L-type calcium channels primarily in the vascular smooth muscle.
Relaxation of the arteries leads to a decrease in systemic vascular resistance and blood pressure.
Coronary vasodilation increases oxygen delivery to cardiac tissues.
Side Effects and Rationales:
Headache and Flushing: Direct results of peripheral vasodilation.
Peripheral Edema: Arteriolar dilation and changes in capillary pressure cause swelling in the ankles or lower legs.
Reflex Tachycardia: The body responds to a drop in blood pressure by increasing the heart rate (especially common at the start of therapy).
Serious Adverse Reactions:
Severe Hypotension: Can cause syncope or tissue ischemia.
Myocardial Ischemia: Immediate-release forms can cause dangerous, rapid shifts in blood pressure and are contraindicated for urgent BP lowering.
Nursing and Patient Education:
Monitor blood pressure and heart rate; assess for edema and frequency of angina.
Swallow extended-release (XL) tablets whole; do not crush or chew them.
Avoid grapefruit and grapefruit juice, as they increase drug levels.
Maintain excellent oral hygiene; CCBs can cause gingival overgrowth (gum tissue hyperplasia).
Note that nifedipine mainly affects blood vessels, unlike verapamil or diltiazem which also affect the heart's electrical conduction.
Verapamil (Calan / Verelan)
Class / Group: Non-dihydropyridine calcium channel blocker; Class IV antiarrhythmic.
Prototype / AKA: Verapamil.
General Clinical Use:
Hypertension, angina, and supraventricular dysrhythmias.
Used for ventricular rate control in rapid atrial rhythms.
Selected when both arterial relaxation and slowing of the heart's conduction are therapeutic goals.
Mechanism of Action:
Blocks L-type calcium channels in the cardiac muscle and the vascular smooth muscle.
Slows conduction through the sinoatrial (SA) and atrioventricular (AV) nodes.
Decreases myocardial contractility (negative inotropy) and heart rate.
Side Effects and Rationales:
Constipation: Verapamil significantly slows the smooth muscle of the gastrointestinal tract; this is a very common side effect.
Bradycardia and Fatigue: Due to reduced heart rate and contractility.
Peripheral Edema and Dizziness: Caused by arterial vasodilation.
Serious Adverse Reactions:
AV Block: Severe slowing of conduction can significantly reduce cardiac output.
Worsening Heart Failure: The negative inotropic effect can be dangerous in patients with a reduced ejection fraction.
Nursing and Patient Education:
Check blood pressure and take an apical pulse before administration.
Use with extreme caution alongside beta blockers and digoxin; verapamil can raise digoxin levels and cause excessive AV node slowing.
Do not crush extended-release products and avoid grapefruit juice.
Report symptoms of heart failure (shortness of breath, swelling) or severe constipation.
Diltiazem (Cardizem)
Class / Group: Non-dihydropyridine calcium channel blocker; Class IV antiarrhythmic.
Prototype / AKA: Diltiazem.
General Clinical Use:
Hypertension and angina.
Rate control for atrial fibrillation, atrial flutter, and supraventricular tachycardias.
Optimizes filling time by slowing the heart while simultaneously dilating coronary arteries.
Mechanism of Action:
Blocks L-type calcium channels in both cardiac and vascular tissues.
Increases the refractory time of the AV node and slows conduction.
Promotes arterial relaxation to lower afterload and oxygen demand.
Side Effects and Rationales:
Bradycardia: Directly suppresses the SA and AV nodes.
Dizziness, Headache, and Edema: Result from the drug’s vasodilatory effects.
Constipation: Generally less severe than the constipation seen with verapamil.
Serious Adverse Reactions:
Severe Bradycardia or AV Block: Can lead to syncope.
Negative Inotropy: May exacerbate heart failure in susceptible individuals.
Nursing and Patient Education:
Monitor blood pressure, apical pulse, and ECG.
Monitor for signs of heart failure and peripheral edema.
Swallow extended-release tablets whole and screen for grapefruit consumption.
Exercise caution when combining with other drugs that slow the AV node, such as beta blockers.
Metoprolol (Lopressor / Toprol XL)
Class / Group: Cardioselective beta-1 adrenergic blocker.
Prototype / AKA: Metoprolol.
General Clinical Use:
Hypertension, angina, and protection following a myocardial infarction (MI).
Rate control for rhythms like supraventricular tachycardia (SVT).
Heart failure (specifically using extended-release dosing).
Reduces myocardial workload and oxygen consumption.
Mechanism of Action:
Selectively blocks beta-1 receptors in the heart and the juxtaglomerular cells of the kidney.
Decreases heart rate, contractility, and the release of renin.
Side Effects and Rationales:
Fatigue and Cold Extremities: Reduced cardiac output can lead to intolerance of exercise and cold hands/feet.
Bradycardia and Hypotension: Predictable effects of blocking beta-1 stimulation.
Sexual Dysfunction: Potential side effect of beta-blocker therapy.
Serious Adverse Reactions:
Hypoglycemia Masking: Beta blockers can hide tachycardia, which is a primary warning sign of low blood sugar in diabetic patients.
Rebound Tachycardia: Abruptly stopping metoprolol can trigger rebound angina, MI, or life-threatening dysrhythmias.
Nursing and Patient Education:
Heart Rate Threshold: Check apical pulse and blood pressure; do not administer if the heart rate is less than beats per minute.
Tapering: Never stop the medication suddenly; it must be tapered as prescribed.
Selectivity Note: Be aware that cardioselectivity (targeting only beta-1) decreases at higher doses.
Take the medication with or immediately following a meal.
Report new wheezing (due to potential lung effects), fainting, or worsening shortness of breath.
Propranolol (Inderal)
Class / Group: Nonselective beta-1 and beta-2 blocker; Class II antiarrhythmic.
Prototype / AKA: Propranolol.
General Clinical Use:
Hypertension and hypertensive crisis.
Management of angina, dysrhythmias, and performance anxiety.
Prevention of tremors and migraine headaches.
Mechanism of Action:
Blocks beta-1 receptors in the heart (slowing HR and contractility) and beta-2 receptors in the lungs and blood vessels.
Reduces renin release and sympathetic nervous system stimulation.
Side Effects and Rationales:
Orthostatic Hypotension: Marked by a drop in blood pressure when sitting or standing, causing lightheadedness.
CNS Effects: Sleep changes and depression may occur because propranolol crosses the blood-brain barrier.
Exercise Intolerance: The heart is unable to increase its rate normally in response to physical activity.
Serious Adverse Reactions:
Bronchospasm: Dangerous in patients with asthma or COPD due to beta-2 blockade in the airways.
Masking Hypoglycemia: Similar to metoprolol, it masks the symptoms of low blood sugar.
Nursing and Patient Education:
Lung Safety: Asthma is a major contraindication or caution. Monitor for new expiratory wheezing and shortness of breath; these are priority findings that require immediate intervention.
Check pulse daily while on the medication.
Instruct the patient to rise slowly and take time moving around to prevent falls.
Monitor ECG when used for rhythm control; avoid abrupt withdrawal.
Carvedilol (Coreg)
Class / Group: Combined alpha- and beta-adrenergic blocker.
Prototype / AKA: Carvedilol.
General Clinical Use:
Hypertension, chronic heart failure, and left-ventricular dysfunction following an MI.
Improves long-term survival in stable heart failure patients.
Mechanism of Action:
Blocks beta-1 and beta-2 receptors (slowing the heart) and alpha-1 receptors (dilating blood vessels).
Concurrent reduction in sympathetic stress, heart rate, and afterload.
Side Effects and Rationales:
Orthostatic Hypotension and Dizziness: result from alpha-1 blockade/vasodilation.
Fluid Retention/Weight Gain: May occur when therapy is first initiated or when doses are increased.
Serious Adverse Reactions:
Initial HF Worsening: Heart failure may temporarily worsen if titration is too rapid.
Bronchospasm: Due to nonselective beta-2 blockade.
Nursing and Patient Education:
Administration with Food: Always give with food to slow absorption, which helps minimize orthostatic hypotension.
Monitor daily weight, edema, apical pulse, and blood pressure.
Start at a low dose and increase slowly.
Report rapid weight gain, fainting, or very slow pulse rates.
Sodium Nitroprusside (Nitropress)
Class / Group: Rapid-acting intravenous (IV) arterial and venous vasodilator.
Prototype / AKA: Sodium nitroprusside.
General Clinical Use:
Treatment of hypertensive emergencies (crises).
Acute decompensated heart failure to rapidly reduce preload and afterload.
Mechanism of Action:
Releases nitric oxide, increasing cyclic GMP in vascular smooth muscle, causing immediate relaxation of arteries and veins.
Side Effects and Rationales:
Reflex Tachycardia and Palpitations: Compensatory responses to rapid blood pressure drops.
Headache and Flushing: Direct results of rapid vasodilation.
Serious Adverse Reactions:
Profound Hypotension: Can lead to irreversible ischemic injury.
Cyanide Toxicity: Can result in metabolic acidosis, mental status changes, cardiovascular collapse, and death.
Thiocyanate Toxicity: Occurs with renal impairment or prolonged use; symptoms include tinnitus, confusion, and hyperreflexia.
Nursing and Patient Education:
Requires continuous blood pressure monitoring and use of an infusion pump in a critical-care setting.
Light Protection: Solution and tubing must be protected from light. Discard the solution if it is discolored.
Monitor neurological status and acid-base balance.
If toxicity is suspected, stop the infusion. Antidotes include sodium thiosulfate or hydroxocobalamin.
Eplerenone (Inspra)
Class / Group: Selective aldosterone antagonist; potassium-sparing diuretic.
Prototype / AKA: Eplerenone.
General Clinical Use:
Hypertension and heart failure after myocardial infarction.
Prevents harmful cardiac remodeling and fibrosis caused by aldosterone.
Mechanism of Action:
Blocks mineralocorticoid receptors in the distal nephron and cardiovascular tissues.
Increases sodium and water excretion while retaining potassium.
Side Effects and Rationales:
Endocrine Effects: Gynecomastia is less common with eplerenone than with spironolactone.
Hypotension and Dizziness: Caused by volume reduction.
Serious Adverse Reactions:
Severe Hyperkalemia: Can cause life-threatening dysrhythmias.
CYP3A Interactions: Strong CYP3A inhibitors can dangerously elevate eplerenone levels.
Nursing and Patient Education:
Assess potassium and renal function before starting therapy, after dose changes, and periodically.
Avoid potassium supplements or salt substitutes.
Report palpitations, severe muscle weakness, or a marked reduction in urine output.