SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
A quantitative spectrophotometric method using Pd(II) chloride as analytical reagent for the determination of polythiazide in pharmaceutical preparations is described in this study. It has been found that polythiazide reacts with Pd(II) chloride in the pH range 3.6-5.8, forming a red, water-soluble (1:1) complex with maximum absorbance at 527 nm. At the optimum pH of 4.8 and an ionic strength mu = 0.1 M, the conditional stability constant of the complex is found to be log K' = 4.77. The molar absorptivity at 527 nm is 3.2 x 10(3) l mol-1 cm-1. Good agreement with Beer's law was found for polythiazide concentrations up to 2.2 mmol l-1. The nominal percent recovery of polythiazide was 99.5% (n = 20). The simplicity, selectivity and sensitivity of the method described is suitable for rapid and accurate determinations of polythiazide in tablets.
An assay for polythiazide, sufficiently sensitive to measure plasma concentrations of this high-potency diuretic agent, has been developed. The assay is based on acid hydrolysis to trifluoroethylthioacetaldehyde and electron-capture gas chromatography. Sensitivity down to 0.2 ng/ml was achieved. In a study in normal human subjects receiving single 1-mg oral doses of polythiazide, the mean plasma half-lives for absorption and elimination were 1.2 and 25.7 hr, respectively. The latter is consistent with the extended duration of action of polythiazide. Approximately 25% of the drug was excreted unchanged in the urine.
A method is presented for the quantitative analysis of polythiazide tablets by high-pressure liquid chromatography. The powdered tablets are extracted with methanol, containing quinoline as the internal standard, and assayed by comparison of peak heights after liquid chromatography. The chromatographic conditions employed may be adapted for the determination of many other thiazide and nonthiazide diuretics.
A high-pressure liquid chromatographic method was developed for the quantitative determination of polythiazide in pharmaceutical tablet formulations after extraction of the powdered tablets with a water-acetonitrile solvent. Analysis is a accomplished by comparison of peak areas after chromatography.
Data are presented on 22 hypertensive patients in an 18-week, double-blind comparison of trimazosin and methyldopa during which treatment with polythiazide was continued. Maximum daily doses of trimazosin and methyldopa were 800 and 2000 mg, respectively. Eight of nine patients receiving trimazosin and 8 of 12 receiving methyldopa had excellent or good overall responses. (One trimazosin patient was not evaluated for overall response.) Quantitative criteria of blood pressure response indicated that trimazosin was as effective as methyldopa. There were no clinically significant changes in results of Holter monitor recordings, ECGs, chest x-ray films, cardiopulmonary tests, or ophthalmoscopy. There were no abnormalities in laboratory tests of trimazosin patients. One patient receiving methyldopa had a positive Coombs' test. Significant side effects developed in two methyldopa patients-syncope in one patient and postural hypotension in the other. No significant side effects occurred in the patients taking trimazosin.
The hypocalciuric response to prolonged polythiazide (PTZ) administration has been investigated in intact and thyroparathyroidectomized (TPTX) rats. After 3 control days, PTZ was given for 6 days (0.1 mg/100 g body weight . 24 h p.o.). In both groups, calcium excretion fell on day 1 of PTZ and remained depressed thereafter. In the intact rats, this decrease was associated with increased sodium excretion and urine output on treatment day 1. In the TPTX rats, hypocalciuria occurred without change in sodium excretion or body weight; urine output increased on the first 2 days. Thus PTZ can reduce calcium excretion in the absence of parathyroid hormone, changes in sodium excretion, and changes in body weight (an estimate of body fluid balance with constant food intake).
Preliminary results of a study of 20 patients show a combination of prazosin and polythiazide to be effective in controlling hypertension not responsive to the diuretic alone. The maximum useful dosage of prazosin was not defined, but increasing the dosage above 15 mg a day did not improve control of blood pressure.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.