Effect Of Telmisartan Or Co-amiloride Add-on Amlodipine Besylate Tablets In Protecting Renal Function

Background: Patients with essential hypertension (EH) usually need≥2 antihypertensives to achieve blood pressure (BP) control.A calcium channel blocker (CCB) plus an angiotensin receptor blocker (ARB) or plus diuretics seems efficiently attractive for these difficult-to-control patients.Aim:To investigate the protection of therapy by CCB (Amlodipine besylate tablets) plus ARB (telmisartan) or diuretics (co-amiloride with 25 mg/d of hydrochlorothiazide and 2.5 mg/d of amiloride hydrochloride) on renal function in patients with essential hypertension. To research whether there are other mechanisms like attenuating oxidative stress or improving endothelial function to take renal protection except the control of blood pressure.Methods: The trial enrolled 54 patients with EH, 34 men, 20 women, mean age was 64.17±7.21. Select standard: Patients with EH didn't treat regularly, with SBP≥160 or DBP≥100mmHg; Patients with EH received monotherapy, with SBP≥140 or DBP≥90mmHg; Patients with EH received therapeutic alliance, the patient's condition allowed to withdrawal for 2 weeks. Elimination standard: secondary hypertension; severity cardiomyopathy, anemo-cardiopathia, or congenital-cardiopathia; unstable angina pectoris; liver disease with ALT or AST raising up; creatinine increased;malignant tumor;arthrolithiasis; taboo to above antihypertensives and so on. 54 patients were assessed at baseline and randomized following a 18-month treatment: co-amiloride group: therapy by amlodipine besylate tablets plus hydrochlorothiazide-amiloride (final dose, amlodipine besylate tablets 5mg; hydrochlorothiazide-amiloride 1 pill; n = 27); telmisartan group: therapy by amlodipine besylate tablets plus telmisartan (final dose, amlodipine besylate tablets 5mg; telmisartan 80 mg; n = 27). Test patients blood pressure and regulate the dose of antihypertensives. After eight weeks if anyone cannot control blood pressure under 140/90mmHg would stop the trial. The patients were evaluated before and after therapy to assess changes in BP, 24h urine albumin excretion rate (UAER), plasma levels of uric acid (UA). Endothelial function was assessed by plasma asymmetric dimethylarginine (ADMA) levels and 8-iso-prostaglandin F2alpha (8-iso-PGF2α) levels as a biomarker of oxidative stress in vivo were measured.Results: Either group has one patient cannot control the BP to normal ,stop the trial. Before treatment the level of BP, UA, UAER and 8-iso-PGF2αhave no significant difference between two groups. After treatment BP of the two groups have no difference. Compared to pre-treatment telmisartan group: UA, UAER, ADMA and 8-iso-PGF2αdecreased significantly, P<0.05; co-amiloride group: UA has a tendency to reduce, but P>0.05,UAER, ADMA and 8-iso-PGF2αdecreased significantly, P<0.05. Between the two groups,in telmisartan group : UA , UAER and 8-iso-PGF2αdecrease significantly, P<0.05.Conclusions: Our findings are a clear-cut demonstration of telmisartan that under the same conditions of blood pressure it is more effective than hydrochlorothiazide-amiloride in patients with essential hypertension. The mechanisms may correlate with attenuating oxidative stress and improving endothelial function.