Antihypertensive Drugs

• Study notes on various drug classes and their indications, mechanisms of action, side effects, and contraindications

Diuretics (Hydrochlorothiazide)

• First-line therapy for hypertension and heart failure.
• Acts on the distal convoluted tubule of the kidney.
• Inhibits reabsorption of sodium, potassium, and chloride, resulting in osmotic water loss.
• Side effects include dizziness, blurred vision, hypotension, hypokalemia, impotence, and decreased libido.
• Overdose can lead to severe hypokalemia.
• Contraindications include drug allergy, anuria, and renal failure.
• More effective on African American patients

Alpha2-Agonist (Clonidine)

• Used for hypertension and management of withdrawal symptoms
• Stimulates alpha2-adrenergic receptors in the brain to reduce sympathetic outflow from the CNS and renin activity in the kidneys.
• Side effects include drowsiness, sedation, dry mouth, and rebound hypertension.
• Use with caution in patients with a history of stroke, recent MI, major depressive disorder, and chronic renal failure.
• Patients taking two doses should take the larger dose at night, and transdermal patches are applied once every seven days

Alpha1 Adrenergic Blockers (Prazosin)

• Used to treat hypertension and decrease resistance to urinary outflow by blocking alpha1-adrenergic receptors.
• Causes arterial and venous dilation, reducing peripheral vascular resistance.
• Side effects include orthostatic hypotension and dizziness.
• First dose often given at night, with safety measures to teach how to avoid orthostatic hypotension.
• Contraindications include hypotension, angina, and renal insufficiency.

Beta Blockers

• Used for angina, hypertension, dysrhythmias, and heart failure.
• Block stimulation of beta receptors in the SNS.
• Can be selective or nonselective, decreasing oxygen demand for angina.
• Side effects/interactions include hypotension, thrombocytopenia, heart failure, mental depression, ischemic colitis, masking signs of hypoglycemia, and potential bronchospasm if a nonselective beta-blocker is given, risk increases with verapamil and diltiazem.
• Rebound hypertension may occur if discontinued abruptly.
• Report weight gain or shortness of breath.
• Take apical pulse daily, administer IV form slowly, more effective in white patients
• Contraindications include non-selective beta-blockers in patients with asthma or COPD due to potential respiratory depression.

Angiotensin Converting Enzymes (ACE Inhibitors)

• Used as first-line drugs for patients with heart failure and hypertension and to slow the progression of left ventricular hypertrophy after MI.
• ACEs block angiotensin-converting enzyme, preventing the formation of angiotensin II and the breakdown of bradykinin.
• Side effects include possible hyperkalemia, dry, nonproductive cough, and angioedema.
• Monitor potassium levels and notify providers of cough, rash, or signs of infection.
• First dose orthostatic hypotension may occur.
• They are more effective in white patients

Angiotensin II Receptor Blockers (ARBs)

• Used for hypertension and stroke prevention, primarily in patients who cannot tolerate ACE inhibitors.
• ARBs block the receptors that receive angiotensin II, preventing vasoconstriction and aldosterone release.
• May be combined with hydrochlorothiazide and can be taken with or without food.
• Less likely to cause hyperkalemia compared to ACE inhibitors.
• Contraindications include liver and kidney dysfunction.

Calcium Channel Blockers

• Used for hypertension, angina, SVT, and migraine headaches
• Relax smooth muscle by blocking calcium to its receptors, which prevents muscle contraction, and vasodilates coronary arteries.
• Side effects include hypotension, palpitations, and tachycardia
• Interactions include beta-blockers and digoxin.
• Extended-release tablets should not be chewed or crushed, and blood pressure and chest pain should be monitored.
• More effective in African-American patients.

Aldosterone Antagonists

• Used for hypertension and heart failure.
• Reduce blood volume by blocking aldosterone receptors in the kidney, promoting excretion of sodium and water.
• Side effects/interactions include hyperkalemia, hyponatremia, flu-like symptoms, and dizziness.
• Administer orally with or without food.
• Contraindications include patients with hyperkalemia, diabetes, and liver impairment.

Direct Renin Inhibitors (Aliskiren)

• Used for hypertension
• Binds with renin to inhibit production of angiotensin I, thus decreasing production of both angiotensin II and aldosterone
• Allergic reaction, hyperkalemia, diarrhea
• High fat meals may interfere with absorption
• May be taken alone or in combination with other medications
• Pregnancy risk during 2 and 3 trimesters
• Hyperkalemia

Class Ia Antiarrhythmic Drugs (Procainamide)

• For Atrial fibrillation and Ventricular Tachycardia
• Blocks sodium fast channels
• delays repolorization
• Side effects include Hypotension, thrombocytopenia, and cardiotoxicity
• Pregnancy Risk Category C
• Contraindications include liver or renal disorders

Class Ib Antiarrhythmic Drugs (Lidocaine)

• For Ventricular dysrhythmias
• Decreases electrical conduction
• Increases the rate of repolarization
• Side effects include CNS and respiratory arrest
• Contraindications include liver and renal dysfunction

Antidysrhythmic Class III (Amiodarone)

• Used for recurrent ventricular fibrillation and ventricular tachycardia.
• Prolongs the action potential and refractory period.
• Decreases electrical conduction and contractility
• Pulmonary toxicity sinus bradycardia and visual disturbances side effects
• High risk of toxicity, and adverse effects may continue until discontinued
• AV block, bradycardia, and liver, thyroid or respiratory dysfunction

Digoxin (Lanoxin)

• Used for atrial fibrillation, atrial flutter, and heart failure.
• Slows conduction between the SA & AV node.
• Decreases in heart rate
• Increases in coronary circulation
• High risk of toxicity so must follow Digoxin levels to determine dose
• Antidote is digoxin immune fab

Adenosine (Adenocard)

• Used for paroxysmal supraventricular tachycardia (PSVT).
• Slows conduction through the AV node.
• Short half-life, only administered as rapid IV push.
• May cause asystole for a few seconds

Aminoglycoside (Gentamycin)

• Used for Infective endocarditis
• Used for multiple infctions
• Bactericidal
• Nephrotoxic and Ototoxic
• Fast IV Push
• Monitor trough levels to monitor therapy
• Use with caution for Patients with Renal failure

Glycopeptide Antibiotic (Vancomycin)

• Used for Multiple indications- endocarditis, respiratory infections, cellulitis
• Bactericidal- inhibits cell wall synthesis
• Nephrotoxic and Ototoxic
• Check trough levels to monitor therapy

Nitrate Uses and Considerations

• Vasodilation Headache and hypotension Tolerance may develop For Acute attacks the patient should lie down Call 911 if chest pain does not diminish after single dose and is in a new location

Isosorbide Dinitrate/Monitrate

• Vasodilation
• Long-term prophylaxis of angina
• Potent dilating effect on coronary arteries

Plavix

• Prevent blood clotting in pt's with cardiac stents
• Antiplatelet

IV-Heparin Administration

• Baseline vital signs
• Need labs (CBC, PLT)
• Monitor APTT for heprain
• Need Activated Partial Thromboplastin Time) every 4-6 hours until stable levels are reached.
• Therapeutic APTT=1.5-2.5X
• For SQ injections, placed in the abdomen at least 2 inches away from the umbilicus

LMWH (Lovenox) Administration

• Prevent DVT in post-op patients, prevent- SQ enoxaparin
• Prevent complications in - treat DVT/PEcertain types of MI Acts primarily on coagulation factor Xa( needed for needed for theproduction of

Oral Anitcoagulants- Warfarin

• Treatment DVT , Prevention of clots in thosew/ AFIB, and prosthetic valves
• Antagonize Vitamin K , preventing factors
• Bleeding, bruising
• St John's wort/Feverfew
• Need PT-INR regularly
• Avoiding foods tomatoes, dark leafeis

Thrombolytics/Fibrinolytic

• DVT/PE, Occlusion of shints or catheters, treatment of acute MI
• Internal-Alterred conscienceness , cardiac dysrhythmias
• Administer Pt education and informed consent is needed

Direct Inhibitor Factor XA +Direct Thrombin Inhibitors

• Oral, prevents DVT and PE in hip/knee pt's
• Bleeding , increased liver enzmes , adminster tab orally the same time and daily