Comparative antihypertensive effects of losartan 50 mg and losartan 50 mg titrated to 100 mg in patients with essential hypertension. Verapamil SR and trandolapril combination therapy in hypertension--a clinical trial of factorial design. German Hypertension Study Group. Effect of spironolactone on systemic blood pressure, limb blood flow and response to sympathetic stimulation in hypertensive patients.
The antihypertensive activity of losartan potassium (losartan, Cozaar), an angiotensin II receptor antagonist, was evaluated in a parallel 12-week, double-blind, placebo-controlled trial in hypertensive patients with mild-to-moderate hypertension. After a 4-week, single-blind, placebo lead-in period, which included monitoring of baseline variables, 366 patients with a group mean sitting diastolic blood pressure of 101 +/- 5 (s.d.) mmHg were assigned randomly to one of three treatment groups: placebo, losartan 50 mg, or losartan 50 mg with the option to titrate to 100 mg after the first 6 weeks if the target sitting diastolic blood pressure (< 90 mmHg) was not reached. To assess the potential blood pressure response associated with the act of titration, patients in the placebo and losartan 50 mg treatment groups with a sitting diastolic blood pressure of > or = 90 mmHg at week 6 were mock titrated (changed to a new tablet containing the same study medication and dose). Sitting diastolic blood pressure was also evaluated at the end of the trial during a 1-week off-drug period to assess for rebound hypertension. At week 6, patients in the active-drug-treatment arms experienced significantly greater peak (6 h post-dose) and trough (24 h post-dose) reduction in systolic and diastolic sitting blood pressures compared with placebo (p < or = 0.01). Based on trough blood pressures at week 12, active drug (both arms) was more effective than placebo in lowering sitting diastolic blood pressure, with a very small additional benefit associated with increasing the dose of losartan to 100 mg in patients who did not reach the target blood pressure after the first 6 weeks on losartan 50 mg. There was no evidence of rebound hypertension during 1 week after withdrawal of losartan. The correlation between baseline plasma renin activity and reduction in peak and trough blood pressure at week 12, although statistically significant, was generally poor in the active treatment groups. In this trial, losartan was efficacious and well tolerated, and was similar to placebo with regard to adverse-experience profile. Adverse experiences that could reasonably be related to excessive lowering of blood pressure were not common and there was no evidence of rebound hypertension. To investigate the dose-response relationship and contribution of verapamil SR and trandolapril given in combination once a day for the treatment of essential hypertension.
                A randomized, double-blind, placebo controlled, factorial, 12 arm parallel group comparison with placebo, verapamil SR (120, 180 mg), trandolapril (0.5, 1.0, 2.0 mg) covering all combinations of both drugs. A 4 week placebo run-in period followed by 6 weeks of treatment. Four hundred and fifty-six patients from office practice (22 centres) with mild to moderate hypertension enrolled and 426 with diastolic pressure > or = 100 mm Hg at the end of run-in period were randomized. Main outcome measures were reduction in sitting systolic (SBP) and sitting diastolic (DBP) blood pressure.
                The combination of verapamil SR and trandolapril, particularly verapamil SR 180 mg and trandolapril 0.5 or 1.0 mg was significantly superior to both monocomponents at the same dose (P<0.05). For these combinations, the adjusted mean reductions in DBP from baseline to last visit were 14.1 and 16.0 mm Hg, respectively. Response surface analysis provided further evidence that these combinations were optimal for antihypertensive efficacy. All treatments were well tolerated. The incidence of adverse events did not differ significantly between treatment groups; the profile of adverse events on combination therapy was mild and consistent with that of each monocomponent.
                All dosage combinations of verapamil SR and trandolapril produced significantly greater reduction of blood pressure than the monotherapy at the same dosage. However, verapamil SR 180 mg in combination with trandolapril 1.0 mg was the dosage with the greatest blood pressure reduction and had the greatest effects compared with the monocomponents. Since there is only scanty, indirect information about the mechanism of the hypotensive effect of spironolactone, 9 patients with essential hypertension were studied according to a randomised double-blind, cross-over protocol. Spironolactone 100mg b.i.d. and placebo were each given for one month and the following parameters were studied: blood pressure, heart rate, response to cold pressure and handgrip tests, as well as blood flow in the calf and finger vessels. Flow in the calf and fingers representing muscle and skin arteries, respectively, was measured semicontinuously with an ECG-triggered venous occlusion plethysmograph. After spironolactone there was a significant decrease in the systolic and diastolic blood pressures in the supine, sitting and standing positions; the sitting systolic and diastolic blood pressure decreased by (mean +/- SE) 27 +/- 4mm Hg (p less than 0.001) and 11 +/- 4mm Hg (p less than 0.02), respectively. No orthostatic response was observed. Heart rate remained unchanged. Blood flow through muscle and skin vessels increased in 6 out of 9 patients, and in these patients calculated vascular resistance in these areas decreased. Spironolactone did not significantly change the response of systemic blood pressure to the handgrip and cold pressure tests. The present data confirm the hypotensive properties of spironolactone and show that this effect is associated with dilatation of muscle and skin arteries in many but not in all the patients. The data do not support the hypothesis that spironolactone decreases the responsiveness of systemic blood pressure to orthosympathetic stimulation.
From the limited available evidence, spironolactone appears to lower blood pressure compared to placebo to a similar degree in patients with primary (essential) hypertension when doses of 100-500 mg/day are given. A dose of 25 mg/day did not statistically significantly reduce systolic or diastolic blood pressure, compared to placebo. Given the lack of a dose-response, coupled with a possible increased risk in adverse events with higher doses, doses of 25 to 100 mg/day are reasonable. There is no evidence of the effect of spironolactone on clinical outcomes in hypertensive patients.