Comparison of trimazosin and methyldopa in hypertension

Abstract

Eighteen patients with hypertension participated in a double-blind, randomized study to evaluate the effect of trimazosin, methyldopa, and placebo on supine and standing blood pressure and heart rate. Of 6 patients on methyldopa, one developed drug fever (and was dropped from the study) and one developed impotence. None of 6 patients on trimazosin and none of 6 patients on placebo developed any adverse effects. The mean supine blood pressure on 900 mg trimazosin daily was 17.0/12.8 mm Hg lower than that on the first placebo trial (p less than 0.01) and 17.0/12.1 mm Hg lower than that on the second placebo trial (p less than 0.01). The mean supine blood pressure on 2,250 mg methyldopa daily was 17.8/12.4 mm Hg lower than that on the first placebo trial (p less than 0.01) and 16.8/13.0 mm Hg lower than that on the second placebo trial (p less than 0.01). The mean supine blood pressure was not significantly affected by placebo. Trimazosin, 900 mg daily, and methyldopa, 2,250 mg daily, were equally effective in lowering supine and standing systolic and diastolic blood pressure and did not affect supine or standing heart rate.

The Cardiovascular Effects of Trimazosin and Prazosin in the Rabbit

“…It is possible that trimazosin being a selective al-adrenoceptor antagonist shares some of these properties with prazosin. The absence of a significant reflex tachycardia with trimazosin in this study is consistent with previous results in man (Aronow et al 1977;de Guia et al 1973;Orlando et al 1978).…”

Methyldopa for primary hypertension

“…Subsequently all other parallel group RCTs' blood pressure data was entered in the same way. One parallel group RCT (Aronow 1977) provided SE of the mean for end of study blood pressure in each treatment group. These SEs were converted to standard deviations (SD).…”

“…An imputed pooled standard error for the di erence in end of study mean blood pressure di erence was used for both trials. The imputed pooled standard error was calculated by using the pooled standard errors from Aronow 1977, Aronow 1978, Mroczek 1974, Fernandez 1980, and Tiwari 1982 to determine a weighted pooled standard error.…”

“…Overall, the quality of the majority of included trials were compromised by incomplete reporting of outcomes data. Specifically, of the 12 included studies, seven trials (Aronow 1977, Lepantalo 1984, Paran 1993, Petrie 1976, Schnaper 1975, Tiwari 1982, Yodfat 1993 either did not adequately report outcomes data for all randomized patients, failed to explain reasons for censoring results data of certain patients, and/or did not provide any details with regards to patients lost to follow up. Most trials did not report their results using the intention-to-treat principle.…”

“…Meta-analyses (Analysis 1.1, Analysis 1.2) of methyldopa's blood pressure lowering e icacy compared to placebo were performed for seven of the 12 included studies (Aronow 1977, Aronow 1978, Fernandez 1980, Mroczek 1974, Paran 1993, Schnaper 1975, Tiwari 1982. From these seven trials, a total of 231 patients were randomized to either methyldopa (N=116) or placebo (N=115) treatment arms.…”