DRUGS TO TREAT ANGINA

Krysia Hudson

Angina

 Defined as:  Chest pain resulting from transient myocardial ischemia  Types:  Chronic stable ((ggoccurring during exercise, stress, exertion)  Unstable (new onset, occurs at rest)  Vasospastic or Prinzmetals (coronary artery vasospasm)

Angina

 Occurs when O2 demand> supply

 PAIN!!!!!!

 Reasons for Angina can be considered as two-fold:  Reduced supply of O2  Increased demand for O2

1 Reduced Supply of O2

 Hemodynamic factors  Obstruction of coronary system =  Increased resistance of coronary vessels (#1 cause)  Platelet aggregation plays a role in obstruction  HtiHypotension  Decreased blood flow (eg hemorrhage)  Cardiac Factors  Valve incompetence  Increased heart rate  Decreased diastolic filling time (due to HR )

Reduced Supply of O2

 Hematologic Factors  Decreased O2 supply in the blood (anemia)

 Systemic Factors (that decrease the availability of O2 – eg shock)

 Lung Disease  COPD

Increased Demand on the Heart

 HTN

 Increased HR  Exercise and Stress

2 Treatment of Angina

 Increase O2 supply  Deliver O2  Improve lung function (sit patient up)  Imppvrove hemody namic function ( administer anticoagulant to prevent platelet adhesion)  Improve hematologic factors (correct anemia)  Improve systemic factors (eg correct shock)  Correct cardiac factors (eg repair heart valve)

Treatment of Angina

 Decrease O2 demand of the heart  Reduce wall tension  Decrease afterload  Decrease preload  Reduce force of contraction  Reduce HR

Drug Therapy of Angina: Nitrates

 Nitrates (prototype: nitroglycerin)  PD:  Reduce preload via venodilation  Preload reduction reduces wall tension  Decreased wall tension decreases O2 demand  Reduces afterload  Increase O2 supply by dilating coronary vessels  PK:  Large First Pass Effect  Must give SL, IV, transdermal

3 Drug Therapy of Angina: Nitrates

 Nursing Mgmt:  When giving SL, have patient sit down or lie down  Place tablet under tongue  If no relief after 5 min, give another SL tablet  If no relief after 5 min, give another SL tablet  If no relief after 5 min, call 911  Toxicity:  Postural hypotension (needs a decrease dose)  Throbbing HA (HA must be >20 minutes)  Reflex tachycardia – the Sympathetic NS is kicking in here

Drug Therapy of Angina: Nitrates

 Contra-indications  Severe anemia  Allergy to adhesives (for transdermal dose)  Hypotension  Hypovolemia  Increased ICP  Constrictive Pericarditis  Pericardial tamponade  Glaucoma

•Increased ICP •Constrictive Pericarditis •Pericardial tamponade •Glaucoma

4 Calcium Channel Blockers: Verapamil

 PD:  Decrease O2 demand through coronary arterial dilation (decrease afterload)  Decrease inotropic state of the heart – decreasing O2 demand (via decreasing automaticity through the SA/AV node)  Used in Prinzmetal’s angina to prevent and reverse coronary spasm  PK:  Large first pass effect

Calcium Channel Blockers: Verapamil

 Adverse Effect:  CONSTIPATION

 Contraindications:  Heart block  Hypotension  Cardiogenic shock  CHF

Beta Blockers: Metoprolol

 PD:  Decrease O2 demand (by decreasing HR and decreasing the force of contraction)  Post- MI – increases survival and reduces risk of new MIs  Discontinuing therapy SHOULD be tapered. Sudden stoppage has resulted in increase of attacks and sudden death  PK:  Large first pass effect  Metabolized by the liver, excreted thru kidneys (also breast milk)

5 Beta Blockers: Metoprolol

 Adverse effects:  If abrupt withdrawal: increase in attacks or death  CNS: cognitive dysfunction or depression  In elderlyypy, hallucinations or psychosis  In diabetics: usage can mask symptoms of hypoglycemia (Tachycardia, palpitations, tremors)  GI: diarrhea, weight gain

Beta Blockers: Metoprolol

 Contraindications:  Bradycardia/heart block  Hypotension  Concommitant use with antidepressants  Constrictive airway diseases (COPD)

Adjunct Therapy

 The following drugs are used in the treatment of angina:  aspirin, clopidogrel, heparin, and statins

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