Classification of antihypertensive drugs, hypertension.pptx

Classification of antihypertensive drugs hypertension pharmacology mpharmacy B.pharmacy

1. Welcome to my power point presentation BP503.T.PHARMACOLOGY-II Mahatma Gandhi Vidya Mandir samaj Shri prashantdada hiray College of pharmacy. Malegaon. Suryawanshi Kunal Anil

2. Hypertension Hypertension literally means an abnormally rasied the arterial blood pressure. There are two types of hypertension.   1. Primary or essential hypertension It is the hypertension in which causes are unknown. 2. Secondary hypertension. It is an a hypertension in which the causes of hypertension is known.  

3. Normal range of blood pressure. Systolic /Diastolic = 120/80. Hypertensive normal Systolic /Diastolic = 140/90 We can deal with a secondary type of hypertension. Causes of secondary type of hypertension. 1. Age 2. Family history 3. Obesity 4. Tobacco and smoking 5. Diet 6. Alcohol 7. Stress conditions.  

4. Regulation of blood pressure. 1. Baroreceptor. Act by changing the activity of sympathetic system. Blood pressure decreases leads to the activation of baroreceptor which result in the increasing sympathetic activity and decreasing the parasympathetic activity. Increasing sympathetic activity leads to the vasoconstriction activity leads to increasing the blood pressure in case of hypertension. 2. Renin angiotensin aldosterone system.

5. Classification of antihypertensive drug. 1. Diuretics. 2. Sympatholytic drugs. 3. Vasodilators. 4. Calcium channel blockers. 5. Angiotensin converting enzyme inhibitor. 6. Potassium channel opener. 7. Angiotensin II receptor antagonist Diuretics :- Diuretics are used as initial drug of choice for mild hypertension in majority of cases. They can be used along with other combination with other classes of antihypertensive drugs. Thiazide. Loop diuretics. Potassium sparing diuretics.

6. 1. Thiazide. Chlorothiazide was the first potent orally effective diuretics. It was soon observed that it loweredblood pressure in hypertensive patient. This was also blocked sodium and chlorine reabsorption from renal tubules leads to the sodium and water loss from the body. Side by side potassium was also lost in the urine causing hypokalemia. Rather than chlorothiazide we can also use hydrochlorothiazide and chlorthalidone. Mode of action:- The thiazides initially induce a sodium and water loss leads to the fall in the plasma volume and extracellular fluids which turns to the lowest the cardiac output and blood pressure. The main advantage of the thiazide are tolerance is not develop.

7. Adverse drug reaction :- Certain degree of hypokalemia can occurs which can be avoided by combination with potassium sparing diuretics. 2. Loop diuretics. The drugs in this class frusemide, bumetamide and the less used ethacrynic acid . They can used in a similar manner as like of thiazide. Loop diuretics in every activity tubular reabsorption of sodium and chlorine in thick ascending loop of henle and the segment of proximal and distal tubule. 3. Potassium sparing diuretics. Spironolactone, triamterene, amiloride produced most diuresis in compare to thiazides and loop diuretics. the important feature is that the loss of sodium is not accompanied by the loss of potassium and their exert potassium sparing effect.

8. 2. Sympatholytic drugs. 1 . Centrally acting agent (methyldopa, clonidine, guanabenz, guanfacine.) 2. Ganglionic blocking agent (trimethaphen) 3. Adrenergic neurone blocking agent (guanethidine, guanadral, reserpine.) 4. Beta adrenergic receptor blockers . (Propranolo, metoprolol, atenolol) 5 . Alpha adrenergic receptor blockers (prazosine, terazosin, doxazosine, phenoxybenzamine) 6. Alpha + beta blocker (labetalol, carvedilol)

9. 1. Centrally acting agent Methyldopa :- Methyldopa (Alpha methyldopa) is recommended for the treatment of most type of hypertension. The potency of methyldopa is lies between guanethidine and reserpine. Methyl dopa is structurally analogous with the dihydroxyphenylamine(dopa). Mode of action of methyldopa :- Earlier it was theories that as methyldopa is an inhibitor of dopa decarboxylase, it impairs the conversion of dopa to dopamine and therapy decreases nonadrenaline synthesis. Methyl dopa converted to Alpha methylnoradrenaline. Methyldopa is alpha 2 receptor agonist located presynaptically. Adverse drug reaction :- Drowsiness, depression, fluid retention, enlargement of breast, drug fever, hepatic dysfunctioning, hemolytic anaemia may occur. The hemolytic anaemia is detected by coombs test.

10. Clonidine, guanabenz, guanfacine :- Clonidine is effective orally and is used primarily in treatment of moderate hypertension. It is an imidazoline in derivative, structurally related to the Alpha blockers phentolamine and tolazoline.Clonidine however is not an Alpha blocker but is an alpha 2 adrenergic receptor agonist. guanabenz and guanafacing :- Have similar to clonidine. Mode of action :- Clonidine, guanabenz and guanfacine are Central adrenoreceptor agonists and inhibit the out flow of sympathetic Vasoconstruction and cardioaccelator impulses from the brainstream. Heart rate slow blood renal blood flow remains unchange. Adverse drug reaction :- drymouth, drowsiness are the most frequent side effect of these agent.

11. Ganglionic blockers :- they act by competitive antagonism with acetylcholine at the cholinergic synapse of autonomic ganglia. They are non selective and block both the sympathetic and parasympathetic ganglia leads to the invertible side-effect of postural hypertension and constipation. Example - trimethaphen. Vasodilator Hydralazine :- Hydralazine is a potent direct relaxant of vascular smooth muscle but often produces considerable relax cardiac stimulation.is drug reduces both systolic and diastolic blood pressure. Heat increases renal blood flow and is useful in hypertension with renal dysfunctioning. Mode of action :- hydralazine in direct dilates the arteries reduces the total peripheral Resistance. Minoxidil, diazoxide, sodium nitroprusside.  

12. Calcium channel blockers :- Varapamil :- Varapamil is calcium channel blocker used in the chronic management of Angela factories and in the control of superventricular arrythamias. Varapamil is also used in relax vascular smooth muscle therapy decreases the peripheral resistance. Angiotensin converting enzyme inhibitor ● Captropil ● Enalapril ● Lisinopril

13. 7. Angiotensen II receptor Antagonists. Losartan Telmisartan Valsartan

14. Thank you. DEPARTMENT OF PHARMACOGNOCY. Prof. V.R Patil Shubham Bhosale & Mayur Markand.