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Journal of Applied Physiology... Apr 2007Acetazolamide, a potent carbonic anhydrase (CA) inhibitor, is the most commonly used and best-studied agent for the amelioration of acute mountain sickness (AMS). The... (Review)
Review
Acetazolamide, a potent carbonic anhydrase (CA) inhibitor, is the most commonly used and best-studied agent for the amelioration of acute mountain sickness (AMS). The actual mechanisms by which acetazolamide reduces symptoms of AMS, however, remain unclear. Traditionally, acetazolamide's efficacy has been attributed to inhibition of CA in the kidneys, resulting in bicarbonaturia and metabolic acidosis. The result is offsetting hyperventilation-induced respiratory alkalosis and allowance of chemoreceptors to respond more fully to hypoxic stimuli at altitude. Studies performed on both animals and humans, however, have shown that this explanation is unsatisfactory and that the efficacy of acetazolamide in the context of AMS is likely due to a multitude of effects. This review summarizes the known systemic effects of acetazolamide and incorporates them into a model encompassing several factors that are likely to play a key role in the drug's efficacy. Such factors include not only metabolic acidosis resulting from renal CA inhibition but also improvements in ventilation from tissue respiratory acidosis, improvements in sleep quality from carotid body CA inhibition, and effects of diuresis.
Topics: Acetazolamide; Adaptation, Physiological; Altitude Sickness; Carbonic Anhydrase Inhibitors; Humans; Oxygen; Oxygen Consumption
PubMed: 17023566
DOI: 10.1152/japplphysiol.01572.2005 -
Neurologic Clinics Feb 2017Idiopathic intracranial hypertension (IIH) is a disorder of elevated intracranial pressure of unknown cause occurring predominantly in young women of childbearing age.... (Review)
Review
Idiopathic intracranial hypertension (IIH) is a disorder of elevated intracranial pressure of unknown cause occurring predominantly in young women of childbearing age. The typical patient symptom profile is the presence of daily headache, pulse synchronous tinnitus, transient visual obscurations, and papilledema with its associated visual loss. Although surgical procedures are performed for those who fail medical therapy, their relative efficacy remains unclear. The main morbidity of IIH is from visual loss. This visual loss is present in most patients and can usually be reversed if recognized early in the patients' course and treated.
Topics: Acetazolamide; Diuretics; Humans; Papilledema; Pseudotumor Cerebri; Randomized Controlled Trials as Topic; Vision Disorders
PubMed: 27886895
DOI: 10.1016/j.ncl.2016.08.004 -
Chest Dec 2020Therapy options for OSA and central sleep apnea (CSA) are limited, thus many patients remain untreated. Clinically, acetazolamide is sometimes used for CSA; however,... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Therapy options for OSA and central sleep apnea (CSA) are limited, thus many patients remain untreated. Clinically, acetazolamide is sometimes used for CSA; however, given overlapping pathophysiologic properties of OSA and CSA, we hypothesized that acetazolamide is equally effective for both types. Prior reviews focused on specific subtypes of sleep apnea, study designs, and languages, thus including few studies (typically ≤3) limiting insights.
RESEARCH QUESTION
How efficacious is acetazolamide for sleep apnea, and is its effect modified by sleep apnea type or acetazolamide dose?
STUDY DESIGN AND METHODS
We queried MEDLINE, EMBASE, and ClinicalTrials.gov from inception until March 11, 2019. Any study in which adults with OSA/CSA received oral acetazolamide vs no acetazolamide (control) that reported sleep apnea-related outcomes was eligible, independent of study design or language. Two reviewers independently assessed eligibility and abstracted data. Primary outcomes were apnea-hypopnea index (AHI) and oxygen saturation nadir. Quality of evidence (QoE) was rated with the use of Grades of Recommendation Assessment, Development and Evaluation methods.
RESULTS
We included 28 studies (13 OSA/15 CSA; N = 542; N = 553) that enabled meta-analyses for 24 outcomes. Acetazolamide doses ranged from 36 to 1000 mg/d and treatment duration from 1 to 90 d (median, 6 d). Overall, acetazolamide vs control lowered the AHI by -0.7 effect sizes (95% CI, -0.83 to -0.58; I = 0%; moderate QoE) that corresponded to a reduction of 37.7% (95% CI, -44.7 to -31.3) or 13.8/h (95% CI, -16.3 to -11.4; AHI = 36.5/h). The AHI reduction was similar in OSA vs CSA, but significantly greater with higher doses (at least up to 500 mg/d). Furthermore, acetazolamide improved oxygen saturation nadir by +4.4% (95% CI, 2.3 to 6.5; I = 63%; no evidence of effect modification; very low QoE) and several secondary outcomes that included sleep quality measures and BP (mostly low QoE).
INTERPRETATION
Short-term acetazolamide improved both OSA and CSA. Rigorous studies with long-term follow up are warranted to assess Acetazolamide's value for the chronic treatment of patients with sleep apnea.
CLINICAL TRIAL REGISTRATION
PROSPERO (CRD42019147504).
Topics: Acetazolamide; Carbonic Anhydrase Inhibitors; Humans; Sleep Apnea, Central; Sleep Apnea, Obstructive; Treatment Outcome
PubMed: 32768459
DOI: 10.1016/j.chest.2020.06.078 -
ESC Heart Failure Dec 2022In the last years, major progress occurred in heart failure (HF) management. Quadruple therapy is now mandatory for all the patients with HF with reduced ejection... (Review)
Review
In the last years, major progress occurred in heart failure (HF) management. Quadruple therapy is now mandatory for all the patients with HF with reduced ejection fraction. Whilst verciguat is becoming available across several countries, omecamtiv mecarbil is waiting to be released for clinical use. Concurrent use of potassium-lowering agents may counteract hyperkalaemia and facilitate renin-angiotensin-aldosterone system inhibitor implementations. The results of the EMPagliflozin outcomE tRial in Patients With chrOnic heaRt Failure With Preserved Ejection Fraction (EMPEROR-Preserved) trial were confirmed by the Dapagliflozin in Heart Failure with Mildly Reduced or Preserved Ejection Fraction (DELIVER) trial, and we now have, for the first time, evidence for treatment of also patients with HF with preserved ejection fraction. In a pre-specified meta-analysis of major randomized controlled trials, sodium-glucose co-transporter-2 inhibitors reduced all-cause mortality, cardiovascular (CV) mortality, and HF hospitalization in the patients with HF regardless of left ventricular ejection fraction. Other steps forward have occurred in the treatment of decompensated HF. Acetazolamide in Acute Decompensated Heart Failure with Volume Overload (ADVOR) trial showed that the addition of intravenous acetazolamide to loop diuretics leads to greater decongestion vs. placebo. The addition of hydrochlorothiazide to loop diuretics was evaluated in the CLOROTIC trial. Torasemide did not change outcomes, compared with furosemide, in TRANSFORM-HF. Ferric derisomaltose had an effect on the primary outcome of CV mortality or HF rehospitalizations in IRONMAN (rate ratio 0.82; 95% confidence interval 0.66-1.02; P = 0.070). Further options for the treatment of HF, including device therapies, cardiac contractility modulation, and percutaneous treatment of valvulopathies, are summarized in this article.
Topics: Humans; Acetazolamide; Heart Failure; Sodium Potassium Chloride Symporter Inhibitors; Stroke Volume; Ventricular Function, Left
PubMed: 36546712
DOI: 10.1002/ehf2.14257 -
European Journal of Heart Failure Sep 2022To describe the baseline characteristics of participants in the Acetazolamide in Decompensated Heart Failure with Volume Overload (ADVOR) trial and compare these with... (Randomized Controlled Trial)
Randomized Controlled Trial
AIMS
To describe the baseline characteristics of participants in the Acetazolamide in Decompensated Heart Failure with Volume Overload (ADVOR) trial and compare these with other contemporary diuretic trials in acute heart failure (AHF).
METHODS AND RESULTS
ADVOR recruited 519 patients with AHF, clinically evident volume overload, elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP) and maintenance loop diuretic therapy prior to admission. All participants received standardized loop diuretics and were randomized towards once daily intravenous acetazolamide (500 mg) versus placebo, stratified according to study centre and left ventricular ejection fraction (LVEF) (≤40% vs. >40%). The primary endpoint was successful decongestion assessed by a dedicated score indicating no more than trace oedema and no other signs of congestion after three consecutive days of treatment without need for escalating treatment. Mean age was 78 years, 63% were men, mean LVEF was 43%, and median NT-proBNP 6173 pg/ml. The median clinical congestion score was 4 with an EuroQol-5 dimensions health utility index of 0.6. Patients with LVEF ≤40% were more often male, had more ischaemic heart disease, higher levels of NT-proBNP and less atrial fibrillation. Compared with diuretic trials in AHF, patients enrolled in ADVOR were considerably older with higher NT-proBNP levels, reflecting the real-world clinical situation.
CONCLUSION
ADVOR is the largest randomized diuretic trial in AHF, investigating acetazolamide to improve decongestion on top of standardized loop diuretics. The elderly enrolled population with poor quality of life provides a good representation of the real-world AHF population. The pragmatic design will provide novel insights in the diuretic treatment of patients with AHF.
Topics: Acetazolamide; Aged; Diuretics; Female; Heart Failure; Humans; Male; Natriuretic Peptide, Brain; Peptide Fragments; Quality of Life; Sodium Potassium Chloride Symporter Inhibitors; Stroke Volume; Ventricular Function, Left; Water-Electrolyte Imbalance
PubMed: 35733283
DOI: 10.1002/ejhf.2587 -
Tremor and Other Hyperkinetic Movements... 2023Episodic ataxia (EA), characterized by recurrent attacks of cerebellar dysfunction, is the manifestation of a group of rare autosomal dominant inherited disorders. EA1... (Review)
Review
BACKGROUND
Episodic ataxia (EA), characterized by recurrent attacks of cerebellar dysfunction, is the manifestation of a group of rare autosomal dominant inherited disorders. EA1 and EA2 are most frequently encountered, caused by mutations in and . EA3-8 are reported in rare families. Advances in genetic testing have broadened the and phenotypes, and detected EA as an unusual presentation of several other genetic disorders. Additionally, there are various secondary causes of EA and mimicking disorders. Together, these can pose diagnostic challenges for neurologists.
METHODS
A systematic literature review was performed in October 2022 for 'episodic ataxia' and 'paroxysmal ataxia', restricted to publications in the last 10 years to focus on recent clinical advances. Clinical, genetic, and treatment characteristics were summarized.
RESULTS
EA1 and EA2 phenotypes have further broadened. In particular, EA2 may be accompanied by other paroxysmal disorders of childhood with chronic neuropsychiatric features. New treatments for EA2 include dalfampridine and fampridine, in addition to 4-aminopyridine and acetazolamide. There are recent proposals for EA9-10. EA may also be caused by gene mutations associated with chronic ataxias (), epilepsy syndromes (), GLUT-1, mitochondrial disorders (), metabolic disorders (Maple syrup urine disease, Hartnup disease, type I citrullinemia, thiamine and biotin metabolism defects), and others. Secondary causes of EA are more commonly encountered than primary EA (vascular, inflammatory, toxic-metabolic). EA can be misdiagnosed as migraine, peripheral vestibular disorders, anxiety, and functional symptoms. Primary and secondary EA are frequently treatable which should prompt a search for the cause.
DISCUSSION
EA may be overlooked or misdiagnosed for a variety of reasons, including phenotype-genotype variability and clinical overlap between primary and secondary causes. EA is highly treatable, so it is important to consider in the differential diagnosis of paroxysmal disorders. Classical EA1 and EA2 phenotypes prompt single gene test and treatment pathways. For atypical phenotypes, next generation genetic testing can aid diagnosis and guide treatment. Updated classification systems for EA are discussed which may assist diagnosis and management.
Topics: Humans; Ataxia; Cerebellar Ataxia; Acetazolamide; Mutation
PubMed: 37008993
DOI: 10.5334/tohm.747 -
Epilepsia Open Sep 2022Acetazolamide is an old drug used as an antiepileptic agent, amongst other indications. The drug is seldom used, primarily due to perceived poor efficacy and adverse... (Review)
Review
Acetazolamide is an old drug used as an antiepileptic agent, amongst other indications. The drug is seldom used, primarily due to perceived poor efficacy and adverse events. Acetazolamide acts as a noncompetitive inhibitor of carbonic anhydrase, of which there are several subtypes in humans. Acetazolamide causes an acidification of the intracellular and extracellular environments activating acid-sensing ion channels, and these may account for the anti-seizure effects of acetazolamide. Other potential mechanisms are modulation of neuroinflammation and attenuation of high-frequency oscillations. The overall effect increases the seizure threshold in critical structures such as the hippocampus. The evidence for its clinical efficacy was from 12 observational studies of 941 patients. The 50% responder rate was 49%, 20% of patients were rendered seizure-free, and 30% were noted to have had at least one adverse event. We conclude that the evidence from several observational studies may overestimate efficacy because they lack a comparator; hence, this drug would need further randomized placebo-controlled trials to assess effectiveness and harm.
Topics: Acetazolamide; Anticonvulsants; Carbonic Anhydrase Inhibitors; Carbonic Anhydrases; Humans
PubMed: 35673961
DOI: 10.1002/epi4.12619 -
European Journal of Heart Failure Nov 2019To investigate the effects of acetazolamide on natriuresis, decongestion, kidney function and neurohumoral activation in acute heart failure (AHF). (Comparative Study)
Comparative Study Randomized Controlled Trial
AIMS
To investigate the effects of acetazolamide on natriuresis, decongestion, kidney function and neurohumoral activation in acute heart failure (AHF).
METHODS AND RESULTS
This prospective, two-centre study included 34 AHF patients on loop diuretics with volume overload. All had a serum sodium concentration < 135 mmol/L and/or serum urea/creatinine ratio > 50 and/or an admission serum creatinine increase of > 0.3 mg/dL compared to baseline. Patients were randomised towards acetazolamide 250-500 mg daily plus bumetanide 1-2 mg bid vs. high-dose loop diuretics (bumetanide bid with daily dose twice the oral maintenance dose). The primary endpoint was natriuresis after 24 h. Natriuresis after 24 h was similar in the combinational treatment vs. loop diuretic only arm (264 ± 126 vs. 234 ± 133 mmol; P = 0.515). Loop diuretic efficiency, defined as natriuresis corrected for loop diuretic dose, was higher in the group receiving acetazolamide (84 ± 46 vs. 52 ± 42 mmol/mg bumetanide; P = 0.048). More patients in the combinational treatment arm had an increase in serum creatinine levels > 0.3 mg/dL (P = 0.046). N-terminal pro-B-type natriuretic peptide reduction and peak neurohumoral activation within 72 h were comparable among treatment arms. There was a non-significant trend towards lower all-cause mortality or heart failure readmissions in the group receiving acetazolamide with low-dose loop diuretics vs. high-dose loop diuretic monotherapy (P = 0.098).
CONCLUSION
Addition of acetazolamide increases the natriuretic response to loop diuretics compared to an increase in loop diuretic dose in AHF at high risk for diuretic resistance.
TRIAL REGISTRATION
ClinicalTrials.gov NCT01973335.
Topics: Acetazolamide; Adult; Aged; Bumetanide; Dose-Response Relationship, Drug; Drug Resistance; Drug Therapy, Combination; Female; Heart Failure; Humans; Kidney Function Tests; Male; Middle Aged; Natriuresis; Prospective Studies; Risk Factors; Sodium Potassium Chloride Symporter Inhibitors; Survival Analysis
PubMed: 31074184
DOI: 10.1002/ejhf.1478 -
Arquivos de Neuro-psiquiatria May 2022Idiopathic Intracranial Hypertension (IIH) is a secondary headache with a steadily growing incidence. Currently, there is little evidence to guide the treatment of IIH. (Review)
Review
BACKGROUND
Idiopathic Intracranial Hypertension (IIH) is a secondary headache with a steadily growing incidence. Currently, there is little evidence to guide the treatment of IIH.
OBJECTIVE
To review the pathophysiology of IIH, with focus on the role of obesity as a risk factor, and the implications for new therapeutic perspectives.
METHODS
in this narrative review, we summarized the current knowledge on treatment options highlighting available evidence for managing intracranial hypertension, obesity, and headache.
RESULTS
Clinical Presentation: headache is the most common symptom and a significant cause of quality-of-life impairment. Visual loss is common in the diagnosis. Pathophysiology: there is no unified theory able to explain all symptoms and the evolution of the disease. There is growing data pointing to metabolic changes and obesity with a central role in IIH pathophysiology. Treatment: most published data on IIH treatment is related to pressure control and protection from visual loss. Acetazolamide and cerebrospinal fluid diversion are the best options available. Optic nerve sheath fenestration might be useful to temporally control the pressure over the optic nerve and thus protect from visual deterioration. Recently, venous sinus stenting has proven to be a safe option in selected cases. Finally, bariatric surgery has proven to effectively control elevated intracranial pressure.
CONCLUSION
IIH is a potential cause of high disability. Early recognition is important, and treatment should be tailored to the needs of each case. There is a lack of research on headache management, which might persist after ICP control.
Topics: Acetazolamide; Headache; Humans; Intracranial Hypertension; Obesity; Pseudotumor Cerebri; Vision Disorders
PubMed: 35976300
DOI: 10.1590/0004-282X-ANP-2022-S110 -
American Journal of Physiology. Renal... Sep 2020Carbonic anhydrase (CAII) binds to the electrogenic basolateral Na-[Formula: see text] cotransporter (NBCe1) and facilitates [Formula: see text] reabsorption across the...
Carbonic anhydrase (CAII) binds to the electrogenic basolateral Na-[Formula: see text] cotransporter (NBCe1) and facilitates [Formula: see text] reabsorption across the proximal tubule. However, whether the inhibition of CAII with acetazolamide (ACTZ) alters NBCe1 activity and interferes with the ammoniagenesis pathway remains elusive. To address this issue, we compared the renal adaptation of rats treated with ACTZ to NHCl loading for up to 2 wk. The results indicated that ACTZ-treated rats exhibited a sustained metabolic acidosis for up to 2 wk, whereas in NHCl-loaded rats, metabolic acidosis was corrected within 2 wk of treatment. [Formula: see text] excretion increased by 10-fold in NHCl-loaded rats but only slightly (1.7-fold) in ACTZ-treated rats during the first week despite a similar degree of acidosis. Immunoblot experiments showed that the protein abundance of glutaminase (4-fold), glutamate dehydrogenase (6-fold), and SN1 (8-fold) increased significantly in NHCl-loaded rats but remained unchanged in ACTZ-treated rats. Na/H exchanger 3 and NBCe1 proteins were upregulated in response to NHCl loading but not ACTZ treatment and were rather sharply downregulated after 2 wk of ACTZ treatment. ACTZ causes renal [Formula: see text] wasting and induces metabolic acidosis but inhibits the upregulation of glutamine transporter and ammoniagenic enzymes and thus suppresses ammonia synthesis and secretion in the proximal tubule, which prevented the correction of acidosis. This effect is likely mediated through the inhibition of the CA-NBCe1 metabolon complex, which results in cell alkalinization. During chronic ACTZ treatment, the downregulation of both NBCe1 and Na/H exchanger 3, along with the inhibition of ammoniagenesis and [Formula: see text] generation, contributes to the maintenance of metabolic acidosis.
Topics: Acetazolamide; Acid-Base Equilibrium; Acidosis; Adaptation, Physiological; Amino Acid Transport Systems, Neutral; Ammonia; Animals; Bicarbonates; Chlorides; Diuretics; Electrolytes; Gene Expression Regulation; Half-Life; Kidney; Male; Rats; Rats, Sprague-Dawley; Urinalysis
PubMed: 32657159
DOI: 10.1152/ajprenal.00501.2019