Antihypertensive and metabolic effects of doxazosin in hypertensive patients with concomitant non-insulin-dependent diabetes mellitus

Effects of Doxazosin and Irbesartan on Blood Pressure and Metabolic Control in Patients with Type 2 Diabetes and Hypertension

The objective of this trial was to compare the metabolic effects of long-term treatment with doxazosin to those of irbesartan in patients with type 2 diabetes and hypertension. We evaluated 96 hypertensive diabetic patients who were randomized to 12 months of double-blind treatment with doxazosin 4 mg/d or irbesartan 300 mg/d. At the end of the study, systolic and diastolic blood pressure (SBP and DBP) were significantly reduced from 152 to 140 mm Hg and from 97 to 87 mm Hg, respectively, with doxazosin (P < 0.01). SBP and DBP were reduced from 150 to 134 mm Hg and from 94 to 83 mm Hg, respectively, with irbesartan (P < 0.01). Irbesartan had significantly better antihypertensive efficacy than doxazosin (P < 0.05). Doxazosin had the greatest effect on glucose metabolism and lipid parameters, with significant (P </= 0.05) reductions observed at study end compared with baseline in glycosylated hemoglobin, fasting plasma glucose, fasting plasma insulin, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, and Homeostasis Model Assessment Index. In conclusion, both doxazosin and irbesartan reduced BP during long-term treatment, but not to recommended levels, and doxazosin had the more beneficial effect on glucose metabolism and lipid profile.

Selective imidazoline agonist moxonidine plus the ACE inhibitor ramipril in hypertensive patients with impaired insulin sensitivity: partners in a successful MARRIAGE?

Hypertension in combination with clinically overt diabetes mellitus is recognized as a particularly powerful combination of risk factors that greatly increases cardiovascular vulnerability. There is also evidence that presumed pre-diabetic conditions such as insulin resistance, hyperinsulinaemia and compensatory hyperglycaemia may amplify overall cardiovascular risk in patients with hypertension, especially when encountered as part of the condition known as metabolic syndrome X (Reaven's syndrome). The long-term benefits of antihypertensive therapy may be compromised if these drugs exert adverse effects on metabolic parameters such as insulin sensitivity, or if they promote a transition from pre-diabetes to overt diabetes. Class differences in the effects of antihypertensives on metabolic indices may therefore be an important consideration when choosing treatment for patients who exhibit these characteristics. Experience from clinical trials suggests that drugs that target the renin-angiotensin system may have metabolic advantages over drugs such as beta-blockers and diuretics, but this conclusion has not been proved definitively. Moxonidine, which selectively targets imidazoline type-1 receptors in the sympathetic vasomotor centres of the rostral-ventrolateral medulla, is an effective antihypertensive and has been reported to exert favourable metabolic effects in preclinical and clinical studies. The MARRIAGE study (Moxonidine And Ramipril Regarding Insulin And Glucose Evaluation) will extend these preliminary observations by comparing the effects of moxonidine and the ACE inhibitor ramipril--and the combination of both drugs--on metabolic and haemodynamic parameters in patients with hypertension and impaired fasting glycaemia. A description is provided of the design and conduct of MARRIAGE.

Effect of doxazosin GITS on blood pressure in hypertensive and normotensive patients: a review of hypertension and BPH studies

Doxazosin is an effective treatment for patients with hypertension, benign prostatic hyperplasia (BPH) and the two comorbidly. In its standard formulation, doxazosin requires a multistep titration regimen to minimize a possible first-dose effect. A new extended-release gastrointestinal therapeutic system (GITS) formulation of doxazosin was developed to improve the pharmacokinetic profile of the parent compound and to reduce or eliminate the need for dose titration and the potential risk of overdosing. This review presents an analysis of the effect of doxazosin GITS monotherapy on blood pressure (BP) and tolerability, as evaluated in four clinical trials, two conducted in patients with stage 1 to stage 2 hypertension and two in patients with BPH with different levels of BP. Doxazosin GITS was as effective as doxazosin standard and more effective than placebo was in reducing and controlling BP in patients with hypertension. Among normotensive patients with BPH, no clinically significant effect on BP was observed and no episodes of syncope were recorded. Doxazosin GITS was generally better tolerated than doxazosin standard, based on the proportion of patients with adverse events and those withdrawing due to adverse events. Moreover, the GITS formulation eliminated the need for titration in most patients. Doxazosin GITS is an effective and well-tolerated treatment in patients with hypertension and/or BPH and without heart failure or clinical coronary heart disease and has advantages over doxazosin standard in terms of a simpler dosing regimen and improved tolerability.