DRUG AFFECTING THE RENIN-ANGIOTENSIN SYSTEM

(1)Angiotensin-converting enzyme inhibitors (ACE inhibitor)
-ACE inhibitor inhibits the conversion of angiotensin I to angiotensin II. They may be the most appropriate initial drug for hypertension in younger patients and those aged over 55 years, and those with primary adolstronism respond less well.

LISINOPRIL

· Indications Essential hypertension, renovascular hypertension used alone or concomitantly with other antihypertensive and also adjunctive of congestive heart failure.
· Cautions Volume & salt depleted patients, renal impairment, elderly, ischaemic heart of cerebrovascular disease, renal artery stenosis.
· Contra-indication Patients with hypersensitivity to ACE inhibitor including angioedema and also pregnancy & lactation.
· Side-effects Dizziness, headache, diarrhea, fatigue, cough, nausea, rash, hypotension, orthostatic effects, asthenia, hyperkalamia.
· Administration can be taken with or without food.
· Drug interaction Diuretics, K-sparing diuretics, K supplements, K-containing salt substitutes, indomethacin, lithium.
· Dosage Essential hypertension initially 10mg. maintenance: 20 mg/day. Adjust dose according to the blood pressure response. Renovascular hypertension initially 2.5-5 mg.
· Presentation & packing Tablet 2.5/5/10/20/30/40mg X 1200 X 10’s

(2)Angiotensin-II receptor antagonist
-They may be used as an alternative to an ACE inhibitor in management of heart failure as well as hypertension.

IRBESARTAN

· Indication Hypertension, renal disease in hypertensive type 2 diabetes mellitus.
· Cautions increased risk of severe hypotension in patients with renal artery stenosis. Patient with recent kidney transplantation, primary aldostronism, aortic or mitral stenosis, renal impairment.
· Contra-indication Pregnancy & lactation
· Side-effects Dizziness, nausea, vomiting, fatigue, orthostatic hypotension & dizziness, musculoskeletal pain.
· Administration can be taken with or without food.
· Drug interaction Increased hypotension effect with other hypotensive agents. K supplements & K-sparing diuretics may lead to increase in serum K.
· Dosage Initial & maintenance dose: 150mg once daily. May be increased to 300mg or other antihypertensive agents can be added. Hypertensive type 2 diabetic patients Initially, 150mg once daily, titrated up to 300mg once daily as preferred maintenance dose for treatment of renal disease. Elderly >75 years & haemodialysis patients Consider initiating with 75mg.
· Presentation & packing Tablet 150/300mg X 28’s

(3)Renin Inhibitors
-They inhibit renin directly, renin converts angiotensinogen to angiotensin I. Aliskiren is licensed for the treatment of hypertensive, either alone or in combination with other antihypertensives.

ALISKIREN

· Indication Essential hypertension.
· Cautions patient taking concomitant diuretic, on a low-sodium diet, renal impairment, renal artery stenosis, diabetes mellitus and heart failure.
· Contra-indication Pregnancy & lactation
· Side-effects diarrhea, less commonly rash, rarely angioedema, anaemia and hyperkalamia also reported.
· Dosage Adult > 18 years 150mg once daily, increased if necessary to 300mg once daily.
· Presentation & packing Tablet 150mg X 28’s (pink), 300mg X 28’s (red)