Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ACETAZOLAMIDE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 901 records · Page 50Linked to original sources
PubMed2000

Acetazolamide reactivity in atherothrombotic, cardioembolic and lacunar infarctions.

Ten cases of atherothrombotic brain infarction, 10 cases of cardioembolic brain infarction, 10 cases of lacunar brain infarction, 10 cases of transient ischemic attack (TIA) and 10 age-matched controls were studied. The cerebral blood flows in the cerebral cortex and cerebral white matter were significantly lower in the atherothrombotic, cardioembolic and lacunar infarction groups than in the TIA and control groups. The acetazolamide reactivity in the cerebral cortex was significantly lower in the atherothrombotic and lacunar infarction groups than in the cardioembolic, TIA and control groups. The rate of association of hypertension was significantly higher in the atherothrombotic, lacunar and TIA groups than in the cardioembolic and control groups. Plasma fibrinopeptide A, platelet factor 4 and beta-thromboglobulin concentrations were higher in the atherothrombotic, cardioembolic and lacunar groups than in the TIA and control groups. The present study suggests that the degree of thrombolysis and platelet activation is less in TIA than in cerebral infarction and that underlying cerebral arteriosclerosis is more severe in atherothrombotic and lacunar infarction than in cardioembolic infarction.

Acetazolamide↗
PubMed2000

The value of acetazolamide challenge test in the evaluation of acute stroke.

The acetazolamide (ACZ) challenge test provides a useful information about compromised hemodynamic state in chronic stroke. However, there is no consensus whether this test is of any value in the evaluation of acute ischemic stroke. The purpose of this study is to examine the value of ACZ challenge test in the management of acute ischemic stroke. Study 1: Nineteen patients with acute embolic stroke were subjected to the Xe CT with and without ACZ (17 mg/kg, i.v.) within 6 hours from the onset. The cases included 12 middle cerebral artery (MCA) occlusions and 7 internal carotid artery (ICA) occlusions. The baseline cerebral blood flow (CBF) values and cerebrovascular reserve (CVR) (% increase in CBF after ACZ) were analyzed in 53 affected regions of interest (ROI). The study indicated that the CBF threshold of subsequent permanent infarction was 15 ml/100 g/min and the ROI with negative CVR had a higher incidence of hemorrhagic infarction. Study 2: Xe-CT with and without ACZ was performed in 32 patients with acute occlusion of the main trunks of cerebral arteries within 6 hours after the onset. Occluded arteries were MCA in 20 patients, ICA in 7, both ICA and MCA in 4 and anterior cerebral artery (ACA) in one. The abnormal hemispheric CBF (< 20 ml/100 g/min) and CVR (< 10%) were correlated with the Glasgow outcome scales of the patients. The predictability of Good Recovery, Moderately Disabled, Severely Disabled, Vegetative Survival and Dead were 80%, 50%, 50%, 100% and 100% by CBF criteria, and 80%, 60%, 80%, 100% and 100% by CVR criteria, respectively. There was no significant increase in the predictability of final outcome of the patients by adding the CVR information of the acute stage. The ACZ challenge test has a potential value in the prediction of hemorrhagic transformation of the ischemic regions. It does not increase the predictability of the long-term outcome. We do not recommend performing ACZ challenge test on routine basis in the evaluation of acute ischemic stroke.

Acetazolamide↗
PubMed2001

Measurement of cerebral hemodynamics with perfusion-weighted MR imaging: comparison with pre- and post-acetazolamide 133Xe-SPECT in occlusive carotid disease.

BACKGROUND AND PURPOSE: We generated regional cerebral blood volume (rCBV) and regional cerebral blood flow (rCBF) studies from dynamic susceptibility contrast-enhanced MR images after an intravenous bolus injection of contrast agent (perfusion-weighted imaging [PWI]) by applying indicator dilution theory. We used a multishot echo-planar imaging (EPI) sequence to obtain adequate arterial input function (AIF). Our purpose was to compare the cerebral hemodynamics measured by PWI with the rCBF values and cerebral perfusion reserve obtained by xenon-133 single-photon emission CT (133Xe-SPECT). METHODS: Eight patients with chronic internal carotid artery occlusion or stenosis were examined. PWI data were acquired using a multishot EPI sequence, and the AIF was determined automatically. Our procedure was based on indicator dilution theory and deconvolution analysis. To eliminate the effect of superficial vessels, the automatic threshold selection method was used. RESULTS: AIF was adequate to generate rCBF and rCBV images. The rCBF and rCBV images by PWI were superior to 133Xe-SPECT scans in spatial resolution, and the rCBF values obtained by PWI correlated well with those obtained by 133Xe-SPECT. The regions with severely decreased perfusion reserve, which were determined by pre- and post-acetazolamide 133Xe-SPECT, showed significantly lower rCBF and higher rCBV by PWI than did regions with normal and moderately decreased perfusion reserve. CONCLUSION: The rCBF and rCBV images generated by our procedure using PWI data appear to provide important clinical information for evaluating the degree of cerebral perfusion reserve impairment in patients with chronic ischemia.

Acetazolamide↗
PubMed2001

[Evaluation of time dependency of the acetazolamide effect on cerebral hemodynamics as measured by 99mTc-ECD single-photon emission computed tomography].

PURPOSE: Kuwabara et al. have examined the cerebral artery dilation with acetazolamide (ACZ) challenge test using PET. And, they reported that ACZ reaction came out time dependently. We have developed a unique SPECT's method using Technetium-99m ethyl cysteinate dimer (99mTc-ECD) to verify the results obtained by Kuwabara et al. METHOD: 1000 MBq of 99mTc-ECD was exactly divided into three syringes. Each of which was intravenous infused (i.v.) at rest, 7.5, and 20 minutes after ACZ administration. Data collection was started using dynamic SPECT immediately after 99mTc-ECD i.v. at rest. Using necessary data only, SPECT images representing each of the three 99mTc-ECD i.v. was reconstructed. SPECT counts were obtained by the ROI method from each images to calculate relative CBF from rest to 7.5 and 20 minutes after ACZ administration. RESULT: The 18 hemispheres of nine patients in the negative control group in whom ACZ was not loaded. CBF was stable during the three evaluation. The measurement error our method was estimated as small. The 18 hemispheres of nine patients in the positive control group who has normal vasodilatory reserve, CBF was increased by 26.2 +/- 8.1% at 7.5 minutes and 29.3 +/- 13.1% at 20 minutes after ACZ administration. Seven patients with and chronic stage unilateral internal carotid artery severe stenosis and/or occlusion were evaluated as the test group. Case of unaffected side, CBF was increased by 17.6 +/- 6.9% at 7.5 minutes and 24.8 +/- 11.3% 20 minutes after ACZ administration. And, increase rate of CBF in the affected side was 2.8 +/- 1.6% at 7.5 minutes and 17.3 +/- 5.0% at 20 minutes after ACZ administration. In the affected side, timing of the maximum CBF increase caused by ACZ was remarkably delayed. CONCLUSION: Our method based on 99mTc-ECD SPECT also revealed delayed cerebral artery dilation in the affected side. It was suggested that ACZ reaction came out time dependently, as reported by Kuwabara et al.

Acetazolamide↗
PubMed1975

The effects of acetazolamide on the human electroretinogram.

The effects of acetazolamied on the cerebral circulation and metabolism was previously shown to be due to a raised PCO2 in brain tissue. The effects of the drug on the human electroretinogram (ERG) are investigated in fifteen human volunteer subjects. A significant increase in the b-wave was found. A similitude with the mechanism of acetazolamide administration in brain and retinal tissue seems to be a possible explanation.

Acetazolamide↗
PubMed2002

Evaluation of delayed appearance of acetazolamide effect in patients with chronic cerebrovascular ischemic disease: feasibility and usefulness of SPECT method using triple injection of ECD.

UNLABELLED: The purpose of this study was to verify the feasibility and usefulness of a new SPECT method, called triple injection of (99m)Tc-ethylcysteinate dimer (TIE), in evaluation of the delayed or poor appearance of acetazolamide (ACZ) effects in patients with chronic cerebral ischemic disease. METHODS: Three equal-volume splits of (99m)Tc-ethylcysteinate dimer were intravenously administered, and 1,000 mg ACZ were used as a vasodilator. A middle cerebral artery territory in the lateral ventricle was used as a region of interest. The data at rest and at 7.5 and 20 min after ACZ challenge (ACZ 7.5 and ACZ 20, respectively) were obtained by dynamic SPECT, and a time response curve to ACZ was obtained through the relative ratio of regional counts to the data at rest, not through regional cerebral blood flow. Nine cases of complete occlusion of the internal carotid artery (IC) and 6 cases of severe IC stenosis were analyzed. RESULTS: In 12 healthy volunteers (24 cerebral hemispheres) using a placebo (negative control), the values at rest and at rest 7.5 and rest 20 (corresponding to ACZ 7.5 and ACZ 20, respectively) were 100%, 100.4% +/- 2.8%, and 99.6% +/- 3.6%, respectively, indicating the accuracy of the TIE method. In a positive control using 24 normal cerebral hemispheres, prompt maximal vasoreactivity at ACZ 7.5 (124.5% +/- 8.0%) was confirmed, as was continuous vasoreactivity until ACZ 20 (130.1% +/- 12.8%). The values between ACZ 7.5 and ACZ 20 were not statistically different. Patients with complete IC occlusion exhibited a poor response at ACZ 7.5 despite a normal response at ACZ 20 (delayed response). Furthermore, in patients with severe IC stenosis, restoration of cerebrovascular reactivity after carotid endarterectomy was confirmed not only at ACZ 20 but also at ACZ 7.5. CONCLUSION: The TIE method using SPECT may be a potentially useful and sensitive strategy in clinical evaluation of the delayed or poor appearance of ACZ effects in patients with chronic cerebrovascular ischemic disease.

Acetazolamide↗
PubMed1976

Effect of acetazolamide on sodium reabsorption in the diluting segment in man.

The purpose of this study is to compare the effects of extracellular volume expansion (ECVE) and acetazolamide (ACTZ) on the transport of sodium in the diluting segment in man. All studies were performed at the peak of sustained oral water diuresis (Uosm. less than 75 mOsm. per kilogram). Distal delivery was estimated by the rate of urine flow and distal sodium reabsorption was approximated by the generation of free water. Free water clearance for given rates of distal delivery expressed as V(range 10 to 35 ml. per minute) was significantly lower and the clearance of sodium higher in the ACTZ group as compared with subjects with ECVE. However when CH2O was plotted against distal delivery expressed as CC1 + CH2O, no difference was detected between ACTZ and ECVE studies. We interpret these findings as suggesting that ACTZ does not have a direct inhibitory influence on the NaCl pump at the diluting site. Rather, the lowering of CH2O/V following ACTZ is due to the flooding of the diluting site with the poorly reabsorbable bicarbonate ion. Thus, the proximal action of ACTZ, which initiates urinary bicarbonate loss results secondarily in an apparent interference with the diluting mechanism in man.

Absorption↗
PubMed1976

Amelioration of the symptoms of acute mountain sickness by staging and acetazolamide.

Treatment by 4 d of residence at 1600 m plus the administration of 500 mg acetazolamide b.i.d. for the last 2 d at 1600 m and the first 2 d at 4300 m was compared with no treatment prior to ascent to 4300 m for prophylaxis of acute mountain sickness. The treatment successfully prevented almost all symptoms of acute mountain sickness. It had no effect on the diminished capacity for maximal or prolonged heavy physical work. The treatment produced a relative acidosis and a comparatively greater arterial oxygen tension at 4300 m.

Acclimatization↗
PubMed2003

Differences in vasodilatory capacity and changes in cerebral blood flow induced by acetazolamide in patients with cerebrovascular disease.

UNLABELLED: To investigate changes in cerebral blood flow (CBF) and blood volume induced by acetazolamide (ACZ) in patients with a variable autoregulatory status responding to reduced perfusion pressure, PET measurements of hemodynamic parameters were performed on patients with cerebrovascular disease, and the relationships between the parameters were evaluated. METHODS: Sixteen patients with unilateral major cerebral arterial occlusive disease underwent PET studies with (15)O-gas and the steady-state method to obtain hemodynamic parameters in the brain. All patients and 8 healthy volunteers underwent H(2)(15)O PET at baseline and 10 min after ACZ injection to calculate the CBF and arterial-to-capillary blood volume (V(0)) based on a 2-compartment model. RESULTS: The regional CBF (rCBF) and V(0) increased significantly after ACZ administration in volunteers and in the hemisphere contralateral to the ischemic side in patients. However, in a subgroup of patients with disease who showed a significant reduction in the rCBF increase in the ipsilateral hemisphere, the ACZ challenge caused a decrease in the rCBF even though the V(0) showed a significant increase. The reduction in the rCBF increase was associated with an asymmetric increase in oxygen extraction fraction (OEF) but not with an absolute OEF increase. CONCLUSION: The increases in rCBF and V(0) induced by ACZ administration, as well as absolute OEF value in the baseline condition, did not necessarily parallel each other in the ipsilateral hemispheres of patients. Thus, the increase in rCBF after ACZ challenge may not represent vasodilatory capacity in patients with cerebrovascular disease, especially in the regions with a reduced rCBF response.

Acetazolamide↗
PubMed1976

The role of cerebral 5-hydroxytryptamine for convulsive threshold and anticonvulsant effect of acetazolamide in rats.

The effect of various substances modifying the activity of serotoninergic system on convulsive threshold and anticonvulsant effect of acetazolamide (ACA) in rats was studied using the electric test. The obtained results are suggestive of 5-hydroxytryptamine (5-HT) playing a significant role for convulsive threshold. On the other hand, the changes in the potency of anticonvulsant effect of ACA resulting from administration of substances altering the level of cerebral 5-HT seems to be secondary to the effect of these substances on convulsive threshold. Additionally, the ACA doses being effective as anticonvulsant were found to increase the cerebral level of 5-hydroxyindoleacetic acid (5-HIAA) and to accelerate the 5-HT turnover.

5,6-Dihydroxytryptamine↗
PubMed1992

[Determination of the cerebrovascular reserve capacity by using acetazolamide as well as transcranial Doppler and SPECT tests].

The aim of this study was the development of a simple bedside test to assess cerebrovascular reserve capacity using transcranial Doppler sonography. We tried to validate the increase in blood flow velocity as cerebrovascular reserve capacity in 20 (3 normal, 7 TIA, 10 completed stroke) patients. They were studied using transcranial Doppler sonography and rCBF SPECT before and after injection of 1 g acetazolamide. Their increases in blood flow velocity and changes in cerebral blood flow correlated significantly in the symptomatic hemispheres (p less than 0.001). Blood flow velocity between the two hemispheres (symptomatic and asymptomatic) was not significantly different at rest. We offer these simple and reliable methods in clinical studies to clarify the frequency of ischemic stroke of hemodynamic origin.

Acetazolamide↗
PubMed2003

Relationship between vasodilatation and cerebral blood flow increase in impaired hemodynamics: a PET study with the acetazolamide test in cerebrovascular disease.

UNLABELLED: The changes in cerebral blood flow (CBF) and arterial-to-capillary blood volume (V(0)) induced by acetazolamide (ACZ) are expected to be parallel each other in the normal circulation; however, it has not been proven that the same changes in those parameters are observed in patients with cerebrovascular disease. To investigate the relationship between changes in CBF, vasodilatory capacity, and other hemodynamic parameters, the ACZ test was performed after an (15)O-gas PET study. METHODS: Twenty-two patients with unilateral major cerebral arterial occlusive disease underwent PET scans using the H(2)(15)O bolus method with the ACZ test after the (15)O-gas steady-state method. CBF and V(0) for each subject were calculated using the 3-weighted integral method as well as the nonlinear least-squares fitting method. After evaluation of accuracy in V(0) values, a new parameter, the CBF/V(0) ratio, which is expected to disclose arterial perfusion pressure, was also compared between the conditions. RESULTS: The regional CBF (rCBF) and V(0) increased significantly after ACZ administration in the hemisphere contralateral to the ischemic side. However, in a subgroup of patients who showed a significant reduction in the rCBF increase in the ipsilateral hemisphere (group A), the ACZ injection caused no change or a slight decrease in rCBF even though the V(0) showed a significant increase. Thus, the increases in rCBF and V(0) did not necessarily parallel each other in the ipsilateral hemispheres of patients who have impaired cerebral circulation. A parameter defined by the rCBF/V(0) ratio decreased significantly in the ipsilateral hemisphere of group A after ACZ administration, although the ratio showed no change in the contralateral hemisphere or in the other subgroup (group B). CONCLUSION: The change in the rCBF/V(0) ratio after ACZ challenge may represent an alteration in arterial perfusion pressure that is expected to indicate a critical hemodynamic status in patients with cerebrovascular disease, especially in patients who have a reduced rCBF response.

Acetazolamide↗
PubMed2004

Constant-infusion H(2)15O PET and acetazolamide challenge in the assessment of cerebral perfusion status.

UNLABELLED: Assessing the baseline perfusion and perfusion reserve after acetazolamide (ACZ) challenge is a common method for the evaluation of patients with cerebrovascular disease. Most previous studies using H(2)(15)O PET applied the bolus injection technique. There is considerable discrepancy regarding the optimal time point of imaging after ACZ injection. The purpose of this study was to continuously monitor cerebral blood flow (CBF) after ACZ using constant-infusion H(2)(15)O PET. METHODS: Four patients with stenoses of an internal carotid artery and 6 with moyamoya disease were studied. H(2)(15)O was continuously infused, and data were recorded in 1-min frames. After equilibration of H(2)(15)O, 5 min of baseline data were acquired, and then 1 g of ACZ was administered intravenously and data collection continued for 10-22 min. Arterial blood was continuously drawn for absolute quantification of CBF. RESULTS: The arterial (15)O concentration remained generally stable during scanning, and the cerebellar blood flow fluctuations of the 5 baseline scans were small. The scan-to-scan difference was 6% (difference of 2 successive scans/mean). In the nonpathologic areas, the increase in CBF started 1-2 min after administration of ACZ. The largest fraction of the increase occurred from 0 to 10 min. The ratio of CBF in pathologic areas to CBF in cerebellum showed an initial decrease that stabilized after 5 min. CONCLUSION: A continuous-infusion protocol is a viable alternative to single bolus injections for the assessment of cerebral perfusion status. Such a protocol is advantageous when the time course of CBF after an intervention is not known. With continuous monitoring, the optimal time point for evaluation of a certain parameter can be chosen post hoc. Furthermore, the time course of CBF itself may allow the definition of new parameters for evaluating perfusion status in cerebrovascular patients, both for assessment before a revascularization procedure and for follow-up. A limitation of the present study is the relatively small number of patients with each type of cerebrovascular disease and the lack of healthy subjects.

Acetazolamide↗
PubMed1991

[Teratogenic effects of acetazolamide in mouse embryos].

The observations gathered in mouse embryos collected 4, 24 and 48 hours after the administration of a teratogenic doses of acetazolamide to their pregnant mothers strongly suggest that the resulting postaxial defects in the anterior limbs can be the result of a selective perturbation of the inductive process responsible for the genesis of the apical ectodermal ridge, probably secondary to a transient acidosis. The vascular stasis provoked by the treatment provides an explanation for the selective localization of the injury in the forelimb buds and even for its preferential occurrence on the right side.

Abnormalities, Drug-Induced↗
PubMed1991

Metabolic acidosis induced by acetazolamide.

The carbonic anhydrase inhibitors that are used most frequently in ophthalmic practice are acetazolamide and methazolamide. They both are weak systemic diuretics and lower intraocular pressure ultimately by decreasing aqueous production. Unfortunately, they have a number of important side effects including the potentiation or exacerbation of metabolic acidosis. In some patients, this pH shift may be quite transient and temporary; whereas, in some patients with other maladies, the acidosis may be much more serious. The patient herein reported had chronic obstructive pulmonary disease and had had a nephrectomy. Close patient monitoring is advisable in these types of patients.

Acetazolamide↗
PubMed1990

Long-term effect of acetazolamide in a patient with retinitis pigmentosa.

The authors studied the therapeutic effect of acetazolamide on a patient with autosomal dominant retinitis pigmentosa complicated by retinal edema. In addition to reduction of macular edema and some improvement of central vision, they found an unexpected progressive increase in extrafoveal retinal sensitivity with prolonged medication. It is proposed that the therapeutic effect is mediated by alteration of retinal pigment epithelial function and that disturbed polarity is restored to a more normal state.

Acetazolamide↗