HF and HTN Medications

• Goal of hypertension medications is to reduce cardiac afterload.

Hypertension Medication Drug Classes

• Diuretics
• Beta Blockers
• ACE Inhibitors
• ARBs
• Calcium Channel Blockers
• Alpha-Adrenergic Blockers

Diuretics

• Furosemide (Lasix) and Hydrochlorothiazide are examples of diuretics.
• Diuretics inhibit sodium reabsorption, promoting water excretion, reducing blood volume and decreasing blood pressure.
• Considerations include monitoring for hypokalemia, ensuring adequate potassium intake, and monitoring electrolytes.

Calcium Channel Blockers

• Amlodipine (Norvasc) and diltiazem (Cardizem) are examples of calcium channel blockers.
• Calcium channel blockers inhibit calcium flow across the cell membrane, relaxing smooth arterial muscle, causing vasodilation and lowering blood pressure.
• Should be avoided in patients with heart blocks.
• Potential to cause constipation, reflex tachycardia.
• Use with caution with digoxin or beta-blockers.

ACE Inhibitors

• Lisinopril (Prinivil) and enalapril (Vasotec) are examples of ACE inhibitors.
• They block ACE preventing the conversion of Angiotensin I to Angiotensin II, dilating arteries, and lowering blood pressure.
• May cause release of kinins resulting in chronic cough, and should be avoided in patients with asthma.

Angiotensin II Receptor Blockers (ARBs)

• Losartan (Cozaar) and valsartan (Diovan) are ARBs.
• ARBs block Angiotensin II from activating receptors, relaxing blood vessels, and lowering blood pressure.
• Headache, dizziness, and orthostatic hypotension need to be monitored.

Beta Adrenergic Blockers

• Metoprolol (Lopressor) and propanolol (Inderal) are examples of beta adrenergic blockers.
• They decrease blood pressure by blocking sympathetic impulses to the heart and blood vessels, reducing heart rate and cardiac output.
• Blood pressure should be monitored for hypotension and pulse for bradycardia.
• These are used for patients with heart failure, coronary heart disease and diabetes who need decreased cardiac workload.

Alpha Adrenergic Blockers

• Terazosin is an example of this type of blocker.
• Alpha-adrenergic blockers work by blocking alpha-receptors in vascular smooth muscle, decreasing vasomotor tone and causing dilation.
• Monitor for reflex tachycardia and palpitations.

Digoxin

• Digoxin increases myocardial contraction, enhancing stroke volume and cardiac output and increasing contractility.
• Cardio-tonic or Inotropic agents are drug classes of Digoxin used in heart failure.
• Digitalis has a positive inotropic effect increasing contraction and intracellular calcium concentration, increasing the amount of calcium available for contraction, while decreasing heart rate.
• Excreted through the kidneys.
• Onset via oral administration is 1 to 2 hours.
• Peak effect is reached in 2 to 6 hours.
• Half-life varies with the preparation.
• The apical pulse should be checked before administering, by notifying a provider if less than 60, and holding if pulse is over 120 as it may be signs of toxicity.
• Use with caution in renal failure due to many drug interactions.
• Electrolyte imbalance, especially potassium (hypokalemia), is a common factor predisposing a patient to digoxin toxicity.
• Toxicity may be treated with digoxin immune Fab (Digibind).

Digoxin Therapeutic Range and Toxicity

• Digoxin therapeutic range is 0.5-2.0 ng/mL.
• Digitalis toxicity refers to toxic drug effects from administration of digoxin.

Digitalis Toxicity Symptoms

• CNS: drowsiness, headache, confusion (more common in older adults), insomnia, muscle weakness
• Cardiovascular: cardiac arrhythmias (bradycardia, first degree AV block), premature ventricular contractions (PVCs), atrial tachycardia
• Eye, ear, nose, throat: double or blurred vision, photophobia, halo appearance (a hallmark sign of digoxin toxicity), single-color vision (typically green or yellow), flickering dots.
• GI: abdominal pain, anorexia, nausea, vomiting, diarrhea.

Digoxin Monitoring and Nursing Management

• Digoxin has a narrow therapeutic range, requiring frequent monitoring including for GI distress, anorexia, nausea and vomiting, and vision or hearing changes.
• Cardiac dysrhythmias can be life-threatening in combination with low serum potassium, magnesium, or elevated calcium.
• The serum Digoxin therapeutic range is between 0.5 and 2.0 ng/mL.
• Check vitals before administering and educate patients to check HR at home prior to administration.
• Patients should be educated to obtain potassium in their diet, ensure compliance in monitoring labs, and when to notify their doctor for signs of toxicity.
• Frequent labs need to be drawn.