NURS 3210 CH 23 PPT

Calcium Channel Blockers for Chronic Stable Angina

• Calcium channel blockers are used to treat chronic stable angina, including:
  • Amlodipine
  • Diltiazem
  • Nicardipine
  • Nifedipine
  • Verapamil

Mechanism of Action

• Calcium channel blockers cause:
  • Coronary artery vasodilation
  • Peripheral arterial vasodilation, decreasing systemic vascular resistance
  • Reduced workload of the heart
  • Decreased myocardial oxygen demand
  • Depression of the automaticity of and conduction through the sinoatrial and AV nodes

Indications

• Calcium channel blockers are used to treat:
  • Angina
  • Hypertension
  • Supraventricular tachycardia
  • Coronary artery spasms (Prinzmetal angina)
  • Short-term management of atrial fibrillation and flutter
  • Migraine headaches
  • Raynaud’s disease
  • Nimodipine: cerebral artery spasms associated with aneurysm rupture

Contraindications

• Calcium channel blockers are contraindicated in:
  • Known drug allergy
  • Acute MI
  • Second- or third-degree AV block (unless the patient has a pacemaker)
  • Hypotension

Adverse Effects

• Calcium channel blockers have:
  • Limited adverse effects
  • Primarily related to overexpression of their therapeutic effects
  • May cause hypotension, palpitations, tachycardia or bradycardia, constipation, nausea, dyspnea, and other adverse effects

Diltiazem (Cardizem, Dilacor, Tiazac)

• Diltiazem is:
  • Very effective for the treatment of angina pectoris resulting from coronary insufficiency and hypertension
  • Used in the treatment of atrial fibrillation and flutter along with paroxysmal supraventricular tachycardia

Amlodipine (Norvasc)

• Amlodipine is:
  • Indicated for both angina and hypertension
  • Available only for oral use

Miscellaneous Antianginal Drug

• Ranolazine (Ranexa) has an unknown mechanism of action.

Nitrates

• Nitroglycerin is:
  • The prototypical nitrate
  • The most important drug used in the symptomatic treatment of ischemic heart conditions such as angina
  • Available in PO, SL, metered-dose aerosol, IV, and topical forms
• Isosorbide dinitrate (Isordil) is an organic nitrate available in rapid-acting sublingual tablets, immediate-release tablets, and long-acting oral dosage forms.

Beta Blockers

• Beta blockers are the mainstay in the treatment of several cardiovascular diseases, including:
  • Angina
  • MI
  • Hypertension
  • Dysrhythmias

Antianginal Beta Blockers

• Antianginal beta blockers include:
  • Atenolol
  • Metoprolol
  • Propranolol
  • Nadolol

Mechanism of Action

• Beta blockers:
  • Block beta1 receptors on the heart
  • Decrease heart rate, resulting in decreased myocardial oxygen demand and increased oxygen delivery to the heart
  • Decrease myocardial contractility, helping to conserve energy or decrease demand
  • Block the harmful effects of catecholamines on the heart, improving survival after MI

Indications

• Beta blockers are used to treat:
  • Angina
  • Hypertension
  • Cardiac dysrhythmias
  • Cardioprotective effects, especially after MI
  • Some are used for migraine headaches, essential tremors, and stage fright

Contraindications

• Beta blockers are contraindicated in:
  • Systolic HF
  • Serious conduction disturbances
  • Caution: bronchial asthma, diabetes mellitus, and peripheral vascular disease

Adverse Effects

• Beta blockers have:
  • Cardiovascular: bradycardia, hypotension, atrioventricular (AV) block
  • Metabolic: hyperglycemia, hypoglycemia, hyperlipidemia
  • Central nervous system: dizziness, fatigue, depression, lethargy
  • Other: impotence, wheezing, dyspnea

Atenolol (Tenormin)

• Atenolol is:
  • A cardioselective beta1-adrenergic receptor blocker
  • Indicated for prophylactic treatment of angina pectoris
  • Shown to decrease mortality after MI

Metoprolol (Lopressor, Toprol-XL)

• Metoprolol is:
  • A cardioselective beta1-adrenergic receptor blocker
  • Indicated for prophylactic treatment of angina
  • Reduces mortality rate in patients after MI and in treating angina
  • Available in oral (immediate release and long acting) and parenteral (injectable) forms

Nursing Implications

• Before administering, perform a complete health history to determine presence of conditions that may be contraindications for use or those that may call for cautious use.
• Obtain baseline vital signs, including respiratory patterns and rate.
• Assess for drug interactions.
• Patients should not take any medications, including over-the-counter medications, without checking with their physicians.
• Patients should be encouraged to limit caffeine intake.
• Patients should report specific symptoms, including blurred vision, persistent headache, dry mouth, edema, fainting episodes, and weight gain.
• Teach patients to change positions slowly to avoid postural BP changes.
• Encourage patients to keep a record of their anginal attacks, including precipitating factors, number of pills taken, and therapeutic effects.