Inotropic agents

1. Inotropic agents

2. Congestive Heart Failure (CHF) • Heart pumps less blood than it receives, so excess blood pools in the chambers and stretches the walls of the heart

3. Discussion Why is it dangerous for blood to pool in the chambers of the heart?

4. Discussion Why is it dangerous for blood to pool in the chambers of the heart? Answer: decreased oxygen supply to tissues; risk of blood clot formation and movement throughout the body

5. 2 MAIN TYPES of CHF SYSTOLIC CHF – insufficiency of output DIASTOLIC CHF - insufficiency of input

6. CHF • Occurs in 10% of the population over 75 • Can result in death through progressive heart damage or sudden death • Overworking of the heart leads to cardiomegaly and myocardial hypertrophy

7. Primary causes: Cardiomyopathy Coronary artery disease Hypertension Secondary causes: High salt intake Noncompliance with treatment Side effects of drug therapy Kidney failure Stress Infection and inflammation Cigarette smoking Obesity Causes of Congestive Heart Failure

8. CARDIAC GLYCOSIDES

9. Purple Foxglove

10. Foxglove

11. Lily of the valley

12. Lychnis

13. Chemical structure of cardiac glycosides

14. Pharmacodynamics Cardiac action Extracardiac action

15. Cardiac action • Positive inotropic • Positive bathmotropic • Negative chronotropic • Negative dromotropic

16. Cardiac Glycosides

17. MECHANISM OF CARDIOTONIC (POSITIVE INOTROPIC) ACTION Of CG • Promote increasing of Calcium ions concentration in myocardiocytes cytoplasm -Transport of Са inside the cell - Stimulate exit of Са from sarcoplasmic reticulum - Block К, Na-АTP-ase (braking repolarization) • Improve usage of macroergic substances by cells, decrease myocardium need in oxygen • Increase tone of sympathetic nervous system

18. Extracardiac action of CG • Diuretic • Sedative • Stimulating influence on smooth muscles

19. MODE of ACTION of CG IN CASE OF CHF • Increasing of systolic and minute volumes of heart activity (enhancing cardiac muscle contractility, thus increasing output) • Improving of circulation in lungs and peripheral organs, decreasing volume of blood circulation, excretion of surplus liquid from the organism • Elimination of hypoxia and metabolic acidosis in tissues

20. The following manifestations testify about therapeutic action of CG1. Improving of general state of the patient (decreasing of weakness, short breath, sleep normalization, disappearing of edema, cyanosis, etc.) 2. Tachycardia transforms into normo (brady)cardia 3. Increasing of diuresis 4. Typical changes in ECG

21. Drug List Agents for CHF • digoxin (Lanoxicaps, Lanoxin) Antidote for digoxin toxicity: • digoxin immune Fab (Digibind)

22. digoxin (Lanoxicaps, Lanoxin) • Increases force of contraction • Increases effective refractory period • Affects SA node, causing direct stimulation

23. digoxin Dispensing Issues • “dig toxicity” • Systemic accumulation Warning!

24. Intoxication with CG Happens frequently - 6-23 % Mortality - over 40 %

26. Intoxication with CG

27. Drug List Agents for CHFVasodilators • milrinone (Primacor) • nitroprusside (Nitropress)

28. ACE Inhibitors • Inhibits conversion of angiotensin I to angiotensin II • Lowers blood pressure and lowers the stress on the heart

29. INHIBITORS OF ANGIOTENSINE CONVERTING ENZYME (IACE) In case of CHF they brake pathological consequences of activation of renin-angiotesine system by inhibiting ACE: • production of angiotensineIIdecreases (vasoconstrictor, inductor of aldosterone, norepinephrine, endothelin secretion, myocardium hypertrophy) • Accumulation of bradikinin (inductor of prostacycline and nitrogen oxide synthesis)

30. INHIBITORS OF ANGIOTESINE CONVERTING ENZYME (IACE) • Increase duration and improve quality of life of patients with CHF • Increase tolerance towards physical loads • Decrease risk of recurring MI • Brake development of myocardium hypertrophy

31. ACE Inhibitor’s Side Effects • Dry, nonproductive cough • Dizziness during first few days

32. ACE Inhibitor Dispensing Issues • Stand slowly to prevent orthostatic hypotension • Avoid salt substitutes • Do not take potassium supplements Warning!

33. Drug List Agents for CHFACE Inhibitors • benazepril (Lotensin) • captopril (Capoten) • enalapril (Vasotec) • fosinopril (Monopril) • lisinopril (Prinivil, Zestril)

34. Drug List Agents for CHFACE Inhibitors • moexipril (Univasc) • perindopril (Aceon) • quinapril (Accupril) • ramipril (Altace) • trandolapril (Mavik)

35. Angiotensin II-Receptor Antagonists • Blocks the action of angiotensin II • Works as well as ACE inhibitors with less coughing and better toleration

36. Angiotensin II-Receptor Antagonist Dispensing Issues • Look-alike and Sound-alike Drugs: • losartan (Cozaar) • valsartan (Diovan) Warning!

37. Drug List Agents for CHF Angiotensin II-Receptor Antagonists Human B-type Natriuretic Peptide (hBNP) • nesiritide (Natrecor)

38. NONGLYCOSIDE CARDIOTONIC DRUGS • Dobutamin – beta1-adrenomimetic - in case of acute and chronic CHF – intravenously dropping – 2,5-5-10 mcg/(kg.min); in case of constant infusion tolerance develops after 3-4 days; in case of increasing of dose – heart arrhythmias • Amrinon, milrinon – inhibitors of phosphodiesterase – for temporary improvement of patient’s condition in terminal stages of CHF