Digitalis and cardiac glycosides Anti hypertensive drugs Mechanism of action

1. Pharmacology :-
Cardiovascular System
o Digitalis and cardiac
glycosides.
o Antihypertensive drugs.

2. •Cardiovascular System
•Structure
• Arteries
• Capillaries
• Veins
• Coronary vessels
• Portal veins
• Heart
• Lungs
• Systemic circulation
• Brain
• Kidneys

3. •Heart
•Pumps oxygenated blood to the body and deoxygenated blood to the lungs.
•There are four chambers in total: left atrium, left ventricle, right
atrium and right ventricle.
•Blood in right atrium is deoxygenated •Passed into the right ventricle to be
pumped through the pulmonary
artery to the lungs for re-
oxygenation and removal of carbon
dioxide.
•The left atrium receives newly oxygenated
blood from the lungs
•The coronary circulation begins near the origin of the aorta by two coronary
arteries: the right coronary artery and the left coronary artery.
•Blood pumped through the aorta
to the different organs of the body.

4. •Lungs
•The circulatory system of the lungs is the portion of the cardiovascular system in
which oxygen-depleted blood is pumped away from the heart, via the pulmonary
artery, to the lungs and returned, oxygenated, to the heart via the pulmonary vein.
•Oxygen deprived blood from the superior and inferior vena cava enters the right
atrium of the heart and flows through the tricuspid valve (right atrioventricular
valve) into the right ventricle, from which it is then pumped through
the pulmonary semilunar valve into the pulmonary artery to the lungs.
•Gas exchange occurs in the lungs, whereby CO2 is released from the blood, and
oxygen is absorbed.
•The pulmonary vein returns the now oxygen-rich blood to the left atrium.
•A separate system known as the bronchial circulation supplies blood to the tissue
of the larger airways of the lung.

5. •Function
•About 98.5% of the oxygen in a sample of arterial blood in a healthy human, breathing
air at sea-level pressure, is chemically combined with hemoglobin molecules.
• About 1.5% is physically dissolved in the other blood liquids and not connected to
hemoglobin.
• The hemoglobin molecule is the primary transporter of oxygen in mammals and many
other species.

6. cardiac glycosides.
• Class of organic compounds
•Increase the output force of the heart and
decrease its rate of contractions by acting on
the cellular sodium-potassium ATPase pump.

7. •Cardenolide
•A five-membered ring
with a single double bond,
at the lactone end.

8. •Bufadienolide
•Bufadienolides and their glycosides are toxic.
•Contain a “dienolide,” a six-membered ring with two
double bonds, at the lactone end.

9. Plants from which cardenolides can be
derived
•Convallaria majalis (Lily of the Valley): convallotoxin
•Antiaris toxicaria (upas tree): antiarin
•Strophanthus kombe (Strophanthus vine): ouabain
and other strophanthins
•Digitalis lanata and Digitalis purpurea (Woolly and purple
foxglove): digoxin, digitoxin
•Nerium oleander (oleander tree): oleandrin
•Asclepias sp. (milkweed): oleandrin
•Adonis vernalis (Spring pheasant's eye): adonitoxin
•Kalanchoe daigremontiana and
other Kalanchoe species: daigremontianin and others

10. •Mechanism of action
• Affect the sodium-potassium ATPase pump in cardiac muscle cells.
•Increases intracellular sodium concentration.
• Cardiac glycosides and potassium compete for binding to the ATPase
pump
• Raised intracellular sodium levels inhibit the function of a second membrane ion
exchanger, NCX, which is responsible for pumping calcium ions out of the cell and
sodium ions in at a ratio of 3Na+
/Ca2+
. Thus, calcium ions are also not extruded and will begin to build up inside the cell as
well
Raised calcium stores in the SR allow for greater calcium release on stimulation, so the
myocyte can achieve faster and more powerful contraction by cross-bridge
cycling. The refractory period of the AV node is increased.

11. •Antihypertensive drug
•Antihypertensive therapy seeks to prevent the complications of high blood pressure,
such as stroke and myocardial infarction.
•Diuretics
•Calcium channel blockers
•ACE inhibitors
•Angiotensin II receptor antagonists
•Adrenergic receptor antagonists
•Vasodilators
•Renin Inhibitors
•Aldosterone receptor antagonists
•Alpha-2 adrenergic receptor agonists
•Endothelin receptor blockers
•Choice of initial medication
•Patient factors
CLASSIFICATION OF DRUGS:-

12. Diuretics help the kidneys eliminate excess salt and water from the body's tissues and
blood.
•Loop diuretics:
•bumetanide
•ethacrynic acid
•furosemide
•torsemide
•Thiazide-like diuretics:
•indapamide
•chlorthalidone
•metolazone
•Potassium-sparing diuretics:
•amiloride
•triamterene
•spironolactone
•Eplerenone
•Thiazide diuretics:
•epitizide
•hydrochlorothiazide and chlorothiazide
•bendroflumethiazide
•methyclothiazide
•polythiazide

13. •Calcium channel blockers
•Dihydropyridines:
•amlodipine
•cilnidipine
•clevidipine
•felodipine
•isradipine
•lercanidipine
•levamlodipine
•nicardipine
•nifedipine
•nimodipine
•nisoldipine
•nitrendipine
•Non-dihydropyridines:
•diltiazem
•verapamil

14. •ACE inhibitors inhibit the activity of angiotensin-converting enzyme (ACE), an enzyme
responsible for the conversion of angiotensin I into angiotensin II, a
potent vasoconstrictor.
•captopril
•enalapril
•fosinopril
•lisinopril
•moexipril
•perindopril
•quinapril
•ramipril
•trandolapril
•benazepril
•ACEinhibitors

15. •Angiotensin II receptor antagonists
•candesartan
•eprosartan
•irbesartan
•losartan
•olmesartan
•telmisartan
•valsartan
•Fimasartan
•azilsartan
•Angiotensin II receptor antagonists work
by antagonizing the activation of angiotensin
receptors.

16. •Adrenergic receptor antagonists
•Beta blockers
•atenolol
•bisoprolol
•betaxolol
•carteolol
•carvedilol
•labetalol
•metoprolol
•nadolol
•nebivolol
•oxprenolol
•penbutolol
•pindolol
•propranolol
•timolol
Alpha blockers:
• doxazosin
• phentolamine
•indoramin
•phenoxybenzamine
•prazosin
•terazosin
•Tolazoline
Mixed Alpha + Beta
blockers:
•bucindolol
•carvedilol
•labetalol

17. Patient factors
•Anxiety may be improved with the use of beta blockers.
•Asthmatics have been reported to have worsening symptoms when using beta blockers.
•Benign prostatic hyperplasia may be improved with the use of an alpha blocker.
•Chronic kidney disease. ACE inhibitors or ARBs should be included in the treatment plan to
improve kidney outcomes regardless of race or diabetic status.
•Diabetes mellitus. The ACE inhibitors and angiotensin receptor blockers have been shown
to prevent the kidney and retinal complications of diabetes mellitus.
•Gout may be worsened by thiazide diuretics, while losartan reduces serum urate.
•Kidney stones may be improved with the use of thiazide-type diuretics
•Heart block. β-blockers and nondihydropyridine calcium channel blockers should not be
used in patients with heart block greater than first degree. JNC8 does not recommend β-
blockers as initial therapy for hypertension
•Heart failure may be worsened with nondihydropyridine calcium channel blockers, the
alpha blocker doxazosin, and the alpha-2 agonists moxonidine and clonidine. On the other
hand, β-blockers, diuretics, ACE inhibitors, angiotensin receptor blockers, and aldosterone
receptor antagonists have been shown to improve outcome.