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Differential antihypertensive effect of acebutolol and hydrochlorothiazide/amiloride hydrochloride combination on elevated exercise blood pressures in hypertensive patients.

Franz IW.

The blood presure abilities of the beta receptor antagonist acebutolol and the fixed diuretic combination of hydrochlorothiazide/amiloride hydrochloride to reduce exercise-induced increases in blood presure durng and after standardized ergometric work were compared in a within-patient study of patients with uncomplicated essential hypertension. Both drugs results in a significant (p < 0.01) and almost identical reduction in blood pressure at rest. However, blood pressure during exercise was significantly lower (p < 0.001) with 500 mg of acebutolol than with 50 mg of hydrochlorothiazide and 5 mg of amiloride. This differential effect of the drugs might be of clinical importance because hypertensive patients are particularly endangered by disproportionately high increases in blood pressure during physical activity that is equal to the applied ergometric work loads. From these findings it is concluded that (1) beta-adrenoreceptor blocking agents are the drugs of first choice in the treatment of mild to moderate arterial hypertension, and (2) diuretic drugs potentiate the antihypertensive effect of beta blocking agents.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6105821&dopt=Abstract hydrochlorothiazide Microzide



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Efficacy of an oral angiotensin-converting enzyme inhibitor (captopril) in severe hypertension.

Zweifler AJ, Julius S, Nicholls MG.

The antihypertensive effect of captopril was assessed during short- and long-term periods in ten patients with elevated blood pressure readings that were uncontrollable by standard therapy (supine diastolic blood pressure of greater than 100 mm Hg with a regimen of propranolol hydrochloride, hydralazine hydrochloride, and hydrochlorothiazide). When given alone, captopril therapy was unable to normalize the blood pressure in any patient. The addition of hydrochlorothiazide to the captopril therapy normalized the blood pressure in one patient and sharply improved the blood pressure in four others. The blood pressure in the remaining patients responded inadequately to this combination. The addition of propranolol to captopril and hydrochlorothiazide reduced the blood pressure further in most cases (seven on the ten patients had normal blood pressure readings while they received these three drugs). In four patients, the blood pressure response to the added propranolol was unrelated to changes in plasma angiotensin II concentration. Captopril was helpful in the management of refractory hypertension in most cases.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6263204&dopt=Abstract hydrochlorothiazide Microzide



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Effects of diazoxide and hydrochlorothiazide on water permeability and sodium transport in the frog bladder.

Marumo F, Mishina T, Shimada H.

The effects of diazoxide and hydrochlorothiazide on vasopressin-induced increments in osmotic water flow and sodium transport across the frog bladder were studied. Diazoxide enhanced the vasopressin-induced osmotic water flow of the bladder, but did not affect the cyclic AMP- or theophylline-induced water flow. Hydrochlorothiazide did not affect the vasopressin-induced water flow. Our results suggest that diazoxide increased the water flow by inhibiting the activity of phosphodiesterase in bladder epithelial cells, whereas hydrochlorothiazide did not. On the other hand, both drugs suppressed the short-circuit current of the bladder membrane and inhibited the Na,K-dependent ATPase activity of the kidney cells. These results suggest that both drugs decreased sodium transport in the bladder by inhibiting Na,K-dependent ATPase activity.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6280212&dopt=Abstract hydrochlorothiazide Microzide



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Chemometric determination of amiloride hydrochloride, atenolol, hydrochlorothiazide and timolol maleate in synthetic mixtures and pharmaceutical formulations.

Ferraro MC, Castellano PM, Kaufman TS.

Area Analisis de Medicamentos, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario (S2002LRK), Argentina.

Different chemometric methods such as classical least squares (CLS), principal components regression (PCR) and partial least squares with one dependent variable (PLS-1) applied on UV spectral data (0 D) and on their first derivatives (1 D) were evaluated for the simultaneous quantification of samples containing mixtures of amiloride hydrochloride, atenolol, hydrochlorothiazide and timolol maleate. Their performances were compared by means of ANOVA tests, which evidenced that 0 D-PCR, 0D-PLS-1, 1D-PCR, 1D-PLS-1, were reproducible and gave statistically similar results, while 0 D-CLS and 1D-CLS displayed higher variances than the former and failed to comply with the Levene's variance homogeneity test at different stages of the method comparison and validation process. The four statistically equivalent procedures were successfully applied to the analysis of synthetic samples with two to four analytes and to commercial tablet preparations containing amiloride hydrochloride and hydrochlorothiazide alone or in association with atenolol or timolol maleate.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15013144&dopt=Abstract hydrochlorothiazide Microzide



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Long-term experience of captopril in the treatment of primary (essential) hypertension.

Karlberg BE, Asplund J, Wettre S, Ohman KP, Nilsson OR.

1 Forty-one patients with primary (essential) hypertension were treated with captopril alone or in combination with hydrochlorothiazide for 12-36 months. 2 During an initial dose-titration period mean blood pressure fell from 174/111 mm Hg to 134/88 mm Hg supine and from 170/116 mm Hg to 126/93 mm Hg standing after 3 months' treatment. 3 During long-term treatment with unchanged or reduced doses of captopril or hydrochlorothiazide, or both, blood pressure remained substantially reduced. Mean supine blood pressure at 24 months was 136/90 mm Hg and at 36 months 138/90 mm Hg. 4 In 12 patients with clearly defined low renin (essential) hypertension initial blood pressure reduction was less than in patients with normal renin hypertension after 1 month's treatment (162/102 mm Hg v 143/92 mm Hg). After 24 months of treatment, however, the treatment results were similar in the two groups. 5 Except for one case of reversible proteinuria no serious side effects were seen during treatment periods of up to three years. 6 Captopril alone or in combination with hydrochlorothiazide seems to be an effective and safe drug in the long-term treatment of primary hypertension.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6753894&dopt=Abstract hydrochlorothiazide Microzide