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Annals of Internal Medicine Dec 1971
Topics: Adult; Aged; Alkalosis; Bendroflumethiazide; Biological Assay; Blood Urea Nitrogen; Bromine; Carbon Dioxide; Chlorides; Chlorpropamide; Chlorthalidone; Creatinine; Diagnosis, Differential; Diuretics; Female; Furosemide; Humans; Hydrochlorothiazide; Hypokalemia; Hyponatremia; Hypopituitarism; Hypothyroidism; Male; Methyclothiazide; Middle Aged; Natriuresis; Osmolar Concentration; Polythiazide; Potassium Isotopes; Radioisotope Dilution Technique; Radioisotopes; Sodium Isotopes; Tritium; Vasopressins; Vomiting; Water-Electrolyte Balance
PubMed: 4944156
DOI: 10.7326/0003-4819-75-6-853 -
Fundamental & Clinical Pharmacology 2000In vitro experiments were designed to assess the inhibitory effect of the thiazide diuretics methyclothiazide (MCTZ), the hydrochlorothiazide (HCTZ), and the...
In vitro experiments were designed to assess the inhibitory effect of the thiazide diuretics methyclothiazide (MCTZ), the hydrochlorothiazide (HCTZ), and the thiazide-related diuretic indapamide (IND) on contractile responses to norepinephrine (NE) and arginine vasopressin (AVP) of aortic rings from spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY). Changes in the tension of aortic ring preparations were measured isometrically. MCTZ (10(-4) M) induced endothelium-dependent inhibition of the vasoconstrictor responses to NE and AVP only in aortas from SHR, and the maximal vasoconstrictive effect of NE and AVP was decreased by 59 +/- 11% and 32.3 +/- 13%, respectively. Indapamide (10(-4) M) also induced endothelium-dependent inhibition of the contractile response to AVP in aortic rings from SHR, and the maximal vasoconstrictive effect of AVP was decreased by 33 +/- 5%. In contrast, HCTZ did not inhibit the contractile response to either NE or AVP, even at the highest concentration. This study provides evidence that methyclothiazide and indapamide inhibit the contractile response induced by norepinephrine and/or arginine vasopressin on SHR aortic preparations via an endothelium-dependent mechanism.
Topics: Animals; Antihypertensive Agents; Aorta; Arginine Vasopressin; Diuretics; Dose-Response Relationship, Drug; Endothelium, Vascular; Hydrochlorothiazide; In Vitro Techniques; Indapamide; Male; Methyclothiazide; Muscle Contraction; Muscle, Smooth, Vascular; Norepinephrine; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Sodium Chloride Symporter Inhibitors; Vasoconstrictor Agents
PubMed: 11030443
DOI: 10.1111/j.1472-8206.2000.tb00417.x -
Drug Development and Industrial Pharmacy Feb 1999The effects of powder substrate composition on the in vitro release properties of methyclothiazide liquisolid compacts were evaluated. The dissolution patterns of this... (Comparative Study)
Comparative Study
The effects of powder substrate composition on the in vitro release properties of methyclothiazide liquisolid compacts were evaluated. The dissolution patterns of this water-insoluble drug formulated in liquisolid tablets were also compared to those of commercial products. According to the new liquisolid technique, liquid medications such as solutions or suspensions of water-insoluble drugs in suitable nonvolatile liquid vehicles can be converted into acceptably flowing and readily compressible powders by a simple admixture with certain powder substrates, which are selected powders referred to as the carrier and coating materials. Enhanced release profiles may be exhibited by such systems due to the increased wetting properties and surface of drug available for dissolution. Liquisolid tablets of methyclothiazide containing a 5% w/w drug solution in polyethylene glycol 400 were prepared using powder substrates of different excipient ratios. The release rates of such products were assessed using the USP dissolution test and were compared to those of their commercial counterparts. It was observed that maximum drug dissolution rates can be exhibited by systems that have powder substrates with optimum carrier-to-coating ratios. In addition, liquisolid tablets displayed significantly enhanced dissolution profiles compared to those of marketed products.
Topics: Chemistry, Pharmaceutical; Diuretics; Dosage Forms; Drug Delivery Systems; Excipients; Methyclothiazide; Powders; Sodium Chloride Symporter Inhibitors; Solubility; Tablets
PubMed: 10065349
DOI: 10.1081/ddc-100102156 -
European Journal of Pharmacology Nov 2000Methyclothiazide (MCTZ), a thiazide diuretic, inhibits the contractile response induced by norepinephrine in aortic rings from 12-week-old spontaneously hypertensive...
Methyclothiazide (MCTZ), a thiazide diuretic, inhibits the contractile response induced by norepinephrine in aortic rings from 12-week-old spontaneously hypertensive rats (SHR). Although not modified by indomethacin, this inhibition was attenuated by either mechanical removal of the endothelium or N omega-nitro-L-arginine (NOLA) treatment. These results suggest that the MCTZ effects on the norepinephrine-evoked vascular response are mediated by an endothelium-dependent mechanism involving endothelium-dependent relaxing factor (EDRF)/nitric oxide (NO) release. MCTZ was also found to alter the contractile response induced by the addition of Ca(2+) to a depolarizing solution, and this inhibitory effect was partially abolished by NOLA application. Our data led us to propose that MCTZ relaxes aortic rings, resulting in an endothelium-dependent relaxation phenomenon that could even be reinforced under high-K(+) depolarizing conditions.
Topics: Animals; Aorta, Thoracic; Calcium Channels; Diuretics; Enzyme Inhibitors; In Vitro Techniques; Male; Methyclothiazide; Muscle Contraction; Muscle, Smooth, Vascular; Nitric Oxide Synthase; Nitric Oxide Synthase Type III; Nitroarginine; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Sodium Chloride Symporter Inhibitors
PubMed: 11070184
DOI: 10.1016/s0014-2999(00)00704-4 -
Diseases of the Chest Dec 1962
Topics: Alkaloids; Antihypertensive Agents; Benzothiadiazines; Humans; Hypertension; Methyclothiazide; Rauwolfia; Reserpine
PubMed: 13929687
DOI: 10.1378/chest.42.6.626 -
Journal of Cardiovascular Pharmacology 1983Methyclothiazide added for 7 weeks to the drinking water of weanling Dahl rats attenuated development of hypertension in salt-sensitive (DS) rats, but did not affect...
Methyclothiazide added for 7 weeks to the drinking water of weanling Dahl rats attenuated development of hypertension in salt-sensitive (DS) rats, but did not affect blood pressure in salt-resistant (DR) ones. There were no appreciable effects on heart rate, body weight, or sympathetic nerve activity. Cardiovascular responses to electrical stimulation of the ventromedial hypothalamus, or to intravenous injections of norepinephrine, tyramine, or vasopressin, were likewise unaffected. These results indicate that the antihypertensive effect of methyclothiazide in DS rats does not depend on sympathetic inhibition.
Topics: Animals; Blood Pressure; Electric Stimulation; Hypertension; Hypothalamus; Male; Methyclothiazide; Rats; Rats, Inbred Strains; Sodium Chloride; Sympathetic Nervous System
PubMed: 6191135
DOI: 10.1097/00005344-198305000-00006 -
Current Therapeutic Research, Clinical... Feb 1967
Topics: Aged; Antihypertensive Agents; Female; Humans; Hypertension; Male; Middle Aged; Phytotherapy; Plants, Medicinal; Rauwolfia; Reserpine
PubMed: 4962534
DOI: No ID Found -
European Journal of Clinical... Dec 1977Home blood pressure measurements were used to assess the effect of methyclothiazide in young essential hypertensive and normotensive males. Although plasma volume was...
Home blood pressure measurements were used to assess the effect of methyclothiazide in young essential hypertensive and normotensive males. Although plasma volume was reduced by approximately 10 percent, blood pressure was not reduced in either group. The lack of effect on blood pressure was probably not attributable to dosage employed, as doubling the dose (5 to 10 mg) in the normal subjects (who were equilibrated on constant diet) did not significantly increase changes in plasma volume, plasma renin activity, aldosterone excretion, urine sodium or blood pressure. The higher dose did result in greater changes in plasma potassium and uric acid. Homeostatic mechanisms which limit the volume mediated and other antihypertensive effects of methyclothiazide apparently achieved complete compensation in these young males. This suggests that thiazide diuretics may not be the drug of first choice in the treatment of hypertension in young adults. Further studies with other diuretics are clearly necessary before the significance of these findings can be fully assessed.
Topics: Adolescent; Adult; Blood Pressure; Blood Pressure Determination; Blood Volume; Depression, Chemical; Electrolytes; Humans; Hypertension; Male; Methyclothiazide; Time Factors
PubMed: 598414
DOI: 10.1007/BF00561058