Acute Myopic Shift after a Single Dose of Acetazolamide: A Case Report and Review of the Literature

We report the case of a 32-year-old male who presented with an acute myopic shift as a result of uveal effusion following a single administration of 250 mg acetazolamide. The drug was discontinued and following cycloplegia and topical steroid therapy, we observed progressive deepening of the anterior chamber, reopening of the iridocorneal angle, and complete resolution of the myopic shift after 5 days. A literature review since 1956 identified 23 cases, including ours, which developed a myopic shift after a median time of 24 h (3 - 24) following a median dose of 500 mg (125 - 1000) acetazolamide, with about a third complicated by angle closure ocular hypertension. This presumed idiosyncratic reaction can occur without prior drug exposure and independent of the phakic status. Treatment options include systematic drug withdrawal associated with cycloplegia, anti-glaucomatous agents, and/or corticosteroids. Full recovery is achieved within about 5 days (2 - 14). Given the widespread use of acetazolamide, awareness of this idiosyncratic reaction is crucial to avoid complications of acute angle-closure glaucoma.

Perianesthetic metabolic acidosis is associated with 2% dorzolamide eye drops in dogs that underwent ophthalmic surgery: a retrospective study (2019-2022)

OBJECTIVE

To evaluate whether the administration of 2% dorzolamide ophthalmic solution in dogs undergoing ophthalmic surgery is associated with perianesthetic metabolic acidosis.

ANIMALS

60 dogs, with or without dorzolamide administration, underwent arterial blood gas analysis immediately after anesthesia for ophthalmic surgery between 2019 and 2022; a total of 60 surgeries were evaluated.

METHODS

This was a retrospective cross-sectional study. Logistic regression analysis was performed to investigate the association between the administration of 2% dorzolamide ophthalmic solution in dogs and the development of metabolic acidosis. Additionally, the influence of various potential risk factors, including age, body weight, sex, use of topical or systemic NSAIDs, and preoperative medications on the occurrence of metabolic acidosis, was evaluated.

RESULTS

A significant association was found between the use of 2% dorzolamide ophthalmic solution and perianesthetic metabolic acidosis (OR, 6.79; 95% CI, 2.00 to 23.02; P = .002). Furthermore, topical dorzolamide administration was significantly associated with both perianesthetic hypokalemia (OR, 3.52; 95% CI, 1.11 to 11.20; P = .033) and perianesthetic hyperchloremia (OR, 9.25; 95% CI, 1.71 to 50.01; P = .010).

CLINICAL RELEVANCE

The use of 2% dorzolamide ophthalmic solution is associated with perianesthetic metabolic acidosis, hypokalemia, and hyperchloremia in dogs. It is prudent to be aware of these risks, especially before anesthesia.

The manifestations of metabolic acidosis during acetazolamide treatment in a cohort of pediatric idiopathic intracranial hypertension

BACKGROUND

Idiopathic intracranial hypertension is characterized by increased intracranial pressure with unidentified pathology. Despite its use as the first-line treatment, data on acetazolamide's effectiveness and safety in pediatric idiopathic intracranial hypertension is sparse. This study's objective was to assess those issues and the need for routine blood gas monitoring during treatment.

METHODS

Retrospective observational cohort study, based on multicenter computerized medical charts of pediatric patients with idiopathic intracranial hypertension diagnosed between 2007-2018 in three medical centers serving one metropolitan area (an estimated population of 400,000 children). Clinical and laboratory data of children up to 18 years old, fulfilling the Friedman criteria and taking acetazolamide, were collected and analyzed.

RESULTS

Sixty-eight patients were included with a mean acetazolamide treatment duration of 8.5 months and a median maximal dose 18 mg/kg/d. Sixty-two children had mild (76%), moderate (13%), or severe (1.5%) metabolic acidosis. At least one adverse effect (neurologic, gastrointestinal, renal) was recorded among 27% of patients. No significant difference was found between the mean pH of children with or without clinical adverse effects (p = 0.35). No correlation was found between laboratory acidosis and adverse effect severity (p = 0.3), or between median acetazolamide dose and acidosis level (p = 0.57).

CONCLUSIONS

Although laboratory finding of metabolic acidosis is common among patients with idiopathic intracranial hypertension treated with acetazolamide, it is not correlated with clinics. Therefore, we recommend sending blood tests during acetazolamide treatment based on clinical judgment. A higher resolution version of the Graphical abstract is available as Supplementary information.

Rapid and Reliable HLA-B*59:01 Genotyping to Prevent Carbonic Anhydrase Inhibitor-Induced Severe Cutaneous Adverse Reactions

OBJECTIVE

Carbonic anhydrase inhibitors (CAIs) are intraocular pressure-reducing medications used in ophthalmology. Human leukocyte antigen-B*59:01 (HLA-B*59:01) is strongly associated with CAI-induced severe cutaneous adverse reactions (SCARs). This study aimed to develop and validate a rapid and economical screening method for HLA-B*59:01 to prevent carbonic anhydrase inhibitor-induced SCARs.

METHODS

Duplex allele-specific polymerase chain reaction (PCR) with an internal control was performed for HLA-B*59:01 genotyping. The accuracy of duplex allele-specific PCR for HLA-B*59:01 genotyping was evaluated in 200 blood samples, using sequence-based typing (SBT) as the reference method.

RESULTS

In total, 50 HLA-B*59:01-positive and 150 HLA-B*59:01-negative results obtained using duplex allele-specific PCR were in complete agreement with the SBT results.

CONCLUSION

Duplex allele-specific PCR is a rapid, reliable, and economical assay for screening the HLA-B*59:01 allele.

Intravenous or Oral Acetazolamide for Treatment of Diuretic-Induced Alkalosis in Patients With Heart Failure

BACKGROUND

Acetazolamide has been used for diuretic-induced metabolic alkalosis, but the preferred dose, route, and frequency of administration remain unknown.

OBJECTIVE

The purpose of this study was to characterize dosing strategies and determine the effectiveness of intravenous (IV) and oral (PO) acetazolamide for patients with heart failure (HF) with diuretic-induced metabolic alkalosis.

METHODS

This was a multicenter, retrospective cohort study comparing the use of IV versus PO acetazolamide in patients with HF receiving at least 120 mg of furosemide for the treatment of metabolic alkalosis (serum bicarbonate CO2 ≥32). The primary outcome was the change in CO2 on the first basic metabolic panel (BMP) within 24 hours of the first dose of acetazolamide. Secondary outcomes included laboratory outcomes, such as change in bicarbonate, chloride, and incidence of hyponatremia and hypokalemia. This study was approved by the local institutional review board.

RESULTS

IV acetazolamide was given in 35 patients and PO acetazolamide was given in 35 patients. Patients in both groups were given a median of 500 mg of acetazolamide in the first 24 hours. For the primary outcome, there was a significant decrease in CO2 on the first BMP within 24 hours after patients received the IV acetazolamide (-2 [interquartile range, IQR: -2, 0] vs 0 [IQR: -3, 1], P = 0.047). There were no differences in secondary outcomes.

CONCLUSION AND RELEVANCE

IV acetazolamide resulted in significantly decreased bicarbonate within 24 hours of administration. IV acetazolamide may be preferred to treat diuretic-induced metabolic alkalosis in patients with HF.

Acetazolamide in Acute Decompensated Heart Failure with Volume Overload

BACKGROUND

Whether acetazolamide, a carbonic anhydrase inhibitor that reduces proximal tubular sodium reabsorption, can improve the efficiency of loop diuretics, potentially leading to more and faster decongestion in patients with acute decompensated heart failure with volume overload, is unclear.

METHODS

In this multicenter, parallel-group, double-blind, randomized, placebo-controlled trial, we assigned patients with acute decompensated heart failure, clinical signs of volume overload (i.e., edema, pleural effusion, or ascites), and an N-terminal pro-B-type natriuretic peptide level of more than 1000 pg per milliliter or a B-type natriuretic peptide level of more than 250 pg per milliliter to receive either intravenous acetazolamide (500 mg once daily) or placebo added to standardized intravenous loop diuretics (at a dose equivalent to twice the oral maintenance dose). Randomization was stratified according to the left ventricular ejection fraction (≤40% or >40%). The primary end point was successful decongestion, defined as the absence of signs of volume overload, within 3 days after randomization and without an indication for escalation of decongestive therapy. Secondary end points included a composite of death from any cause or rehospitalization for heart failure during 3 months of follow-up. Safety was also assessed.

RESULTS

A total of 519 patients underwent randomization. Successful decongestion occurred in 108 of 256 patients (42.2%) in the acetazolamide group and in 79 of 259 (30.5%) in the placebo group (risk ratio, 1.46; 95% confidence interval [CI], 1.17 to 1.82; P<0.001). Death from any cause or rehospitalization for heart failure occurred in 76 of 256 patients (29.7%) in the acetazolamide group and in 72 of 259 patients (27.8%) in the placebo group (hazard ratio, 1.07; 95% CI, 0.78 to 1.48). Acetazolamide treatment was associated with higher cumulative urine output and natriuresis, findings consistent with better diuretic efficiency. The incidence of worsening kidney function, hypokalemia, hypotension, and adverse events was similar in the two groups.

CONCLUSIONS

The addition of acetazolamide to loop diuretic therapy in patients with acute decompensated heart failure resulted in a greater incidence of successful decongestion. (Funded by the Belgian Health Care Knowledge Center; ADVOR ClinicalTrials.gov number, NCT03505788.).

Acetazolamide to Prevent Adverse Altitude Effects in COPD and Healthy Adults

Acetazolamide to Prevent Adverse Altitude Effects Furian and colleagues report on the results of two randomized controlled trials testing the use of acetazolamide to prevent the adverse effects of altitude on healthy older persons and in people with COPD. They find that acetazolamide decreased the incidence of altitude related adverse health events (primarily hypoxemia) in both populations with no evidence of adverse events.

Brinzolamide/brimonidine fixed-dose combination bid as an adjunct to a prostaglandin analog for open-angle glaucoma/ocular hypertension

PURPOSE

To evaluate the additive intraocular pressure-lowering effect of twice-daily brinzolamide 1%/brimonidine 0.2% fixed-dose combination (BBFC) as an adjunct to a prostaglandin analog (PGA) in patients with open-angle glaucoma or ocular hypertension insufficiently controlled with PGA monotherapy.

METHODS

In this Phase 4, double-masked trial, patients aged ⩾18 years, with a mean intraocular pressure of ⩾19 and <32 mm Hg in at least one eye were randomized (1:1) to receive BBFC + PGA (n = 96) or vehicle + PGA (n = 92) for 6 weeks. The primary endpoint was the mean change in diurnal intraocular pressure from baseline (averaged over 09:00 and 11:00 h) at Week 6.

RESULTS

The mean diurnal intraocular pressure at baseline was similar in the BBFC + PGA (22.8 mm Hg) and vehicle + PGA (22.9 mm Hg) groups. The least squares mean change in diurnal intraocular pressure from baseline at Week 6 was greater with BBFC + PGA (-5.59 mm Hg (95% confidence interval: -6.2 to -5.0)) than with vehicle + PGA (-2.15 mm Hg (95% confidence interval: -2.7 to -1.6)); the treatment difference was statistically significant in favor of BBFC + PGA (-3.44 mm Hg, (95% confidence interval: -4.2 to -2.7); p < 0.001). Ocular adverse events were reported in 21.1% and 8.7% of patients in the BBFC + PGA and vehicle + PGA groups, respectively. The most frequent ocular adverse event was ocular hyperemia (5.3%) in the BBFC + PGA group and blurred vision (2.2%) in the vehicle + PGA group.

CONCLUSION

BBFC + PGA significantly reduced mean diurnal intraocular pressure than PGA alone in patients with open-angle glaucoma or ocular hypertension. The safety findings with BBFC + PGA were consistent with the known safety profile of the individual medications.

Can dorzolamide/timolol-fixed combination effectively treat primary open-angle glaucoma?: A protocol for systematic review and meta-analysis

BACKGROUND

Primary open-angle glaucoma (POAG) is a very common disorder, and it is the second leading cause that results in blindness worldwide after cataracts. Previous studies have reported that dorzolamide/timolol-fixed combination (DTFC) can be used in treating POAG. However, there are still inconsistent results. Thus, this study will systematically investigate the efficacy and safety of DTFC on POAG.

METHODS

A comprehensive search will be carried out in Cochrane Library, MEDLINE, EMBASE, CINAHI, ACMD, China National Knowledge Infrastructure, and WANGFANG database from origin to the present. There are no limitations related to the language and publication status. Only randomized controlled trials that assessed the efficacy and safety of DTFC for the treatment of POAG will be included. Two researchers will independently undertake record selection, data extraction, and study quality assessment. Any divisions will be solved by discussion with a third researcher. We will perform statistical analysis using RevMan 5.3 software RESULTS:: This study will summarize the present evidence to identify the efficacy and safety of DTFC in treating POAG through mean intraocular pressure, best corrected visual acuity, contrast sensitivity, bioelectric activity of the retina, rate of progression of glaucoma, quality of life, and adverse events.

CONCLUSIONS

The results of this study will provide evidence of DTFC for the treatment of POAG.

SYSTEMATIC REVIEW REGISTRATION

INPLASY202040120.

Brief report: Metabolic acidosis in newborn infants following maternal use of acetazolamide during pregnancy

 The information regarding fetal effects of acetazolamide use during pregnancy and lactation is sparse. We report the clinical and pharmacodynamic characteristics of maternal acetazolamide use and the timing of its effects on acid-base balance in three cases who presented with metabolic acidosis in the newborn period. We found that the infants' clinical status soon after birth was inconsistently correlated with maternal drug dose and concentrations of medication in maternal serum. However, there was low transfer of the drug in breast milk and its use did not affect clinical symptomatology. We also present a review of literature on this subject to help consolidate our current knowledge on this topic.

Personalized Treatment Response Assessment for Rare Childhood Tumors Using Microcalorimetry-Exemplified by Use of Carbonic Anhydrase IX and Aquaporin 1 Inhibitors

We present a novel approach to a personalized therapeutic concept for solid tumors. We illustrate this on a rare childhood tumor for which only a generalized treatment concept exists using carbonic anhydrase IX and aquaporin 1 inhibitors. The use of microcalorimetry as a refined in vitro method for evaluation of drug susceptibility in organotypic slice culture has not previously been established. Rapid microcalorimetric drug response assessment can refine a general treatment concept when it is applied in cases in which tumors do not respond to conventional chemo-radiation treatment. For solid tumors, which do not respond to classical treatment, and especially for rare tumors without an established protocol rapid microcalorimetric drug response testing presents an elegant novel approach to test alternative therapeutic approaches. While improved treatment concepts have led to improved outcome over the past decades, the prognosis of high risk disease is still poor and rethinking of clinical trial design is necessary. A small patient population combined with the necessity to assess experimental therapies for rare solid tumors rather at the time of diagnosis than in relapsed or refractory patients provides great challenges. The possibility to rapidly compare established protocols with innovative therapeutics presents an elegant novel approach to refine and personalize treatment.

The effects of ex vivo ozone treatment on human erythrocyte carbonic anhydrase enzyme

Ozone autohemotherapy is used in the treatment of some diseases. Carbonic anhydrases (CAs, EC 4.2.1.1) are metalloenzymes and play a role in homeostatic mechanisms. The aim of this study was to investigate the effects of ozone on human red blood cell CA (hCA) enzyme activity. Blood samples were treated with different doses of ozone (10, 20, 30 µg/ml) and the erythrocyte total CA activities were determined. Also, purified hCAI and hCAII isozymes were treated with the same doses of ozone and the enzyme activities were measured. About 30 µg/ml ozone treatment decreased the purified hCAI and hCAII activity and increased the total CA activity compared to the control. Because the implication of CAs on many physiological and biochemical processes is linked to pathologies, it can be suggested that the ozone at a concentration of 30 µg/ml is safely used by autohaemotherapy in a well-designed clinical trial.

Paradoxical Anatomic Response to Topical Carbonic Anhydrase Inhibitor in X-linked Retinoschisis

An 11-year-old boy presented for central vision blurring in each eye. Visual acuity was 20/80 and examination revealed spoke-wheel foveal schisis and peripheral elevated diaphanous inner retina in each eye. Spectral-domain optical coherence tomography showed inner-retinal, flat-topped cysts in each eye. Electrophysiologic testing was refused, but a clinical diagnosis of X-linked retinoschisis was made. Three months after topical dorzolamide (Trusopt; Santen Pharmaceutical, Osaka, Japan) was started, the macular cysts worsened significantly. The medication was stopped and 3 months later, the macular anatomy returned to baseline. Physicians should be aware of this potential paradoxical anatomic response to topical carbonic anhydrase inhibitor therapy in X-linked retinoschisis. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:142-144.].

The Efficacy and Safety of Timolol Maleate versus Brinzolamide Each Given Twice Daily Added to Travoprost in Patients with Ocular Hypertension or Primary Open-Angle Glaucoma

PURPOSE

To compare the efficacy and safety of timolol maleate 0.5% versus brinzolamide 1% when added to travoprost 0.004% in patients with ocular hypertension or primary open-angle glaucoma.

DESIGN

A prospective, double-masked, randomized, active-controlled, parallel comparison.

METHODS

Qualified patients at Visit 1 were placed on travoprost dosed every evening for 4 weeks and then were randomized at baseline (Visit 2) to the addition of timolol maleate or brinzolamide each given twice daily. Patients returned to clinic at Week 4 (Visit 3) for a safety visit and Week 12 (Visit 4) for an efficacy visit. At Visits 2 and 4 the intraocular pressure (IOP) was measured at 08:00, 12:00, and 16:00 hours.

RESULTS

Ninety-seven patients on brinzolamide had a baseline diurnal IOP of 21.5+/-2.2 mmHg and 95 on timolol maleate had 21.3+/-2.5 mmHg, each added to travoprost. The diurnal mean IOP at Week 12 was 18.1+/-2.7 mmHg for brinzolamide and 18.1+/-3.0 mmHg for timolol maleate (p=0.96). There was no statistical difference found between treatment groups in the absolute level of pressure, or in the reduction in IOP from baseline, at each time point or for the diurnal curve (p>0.05). There was no significant difference for any adverse event between groups (p>0.05), with the most common side effect being conjunctival hyperemia in 15/97 (16%) brinzolamide and 6/95 (6%) timolol treated patients (p=0.06).

CONCLUSIONS

This study showed that brinzolamide provides similar safety and efficacy compared to timolol maleate when added to travoprost.

Topiramate and metabolic acidosis: an evolving story

Topiramate is an anticonvulsant that is being increasingly used for a number of different off-label indications. Its inhibition of carbonic anhydrase isoenzymes can lead to metabolic acidosis, elevated urine pH, reduced urine citrate, and hypercalciuria, thereby creating a milieu that is ripe for calcium phosphate stone formation. In this review, we describe a case of topiramate-induced metabolic acidosis. We review the frequency of metabolic acidosis among children and adults, as well as the mechanism of hyperchloremic metabolic acidosis and renal tubular acidosis in topiramate users. Finally, we describe the long-term effects of topiramate-induced metabolic acidosis, including nephrolithiasis, nephrocalcinosis, and bone degradation. Patients who are prescribed topiramate should be carefully monitored for metabolic derangements, and they may benefit from alkali supplementation, or in extreme cases, discontinuation of the drug altogether.

Interventions for preventing high altitude illness: Part 1. Commonly-used classes of drugs

BACKGROUND

High altitude illness (HAI) is a term used to describe a group of cerebral and pulmonary syndromes that can occur during travel to elevations above 2500 metres (8202 feet). Acute hypoxia, acute mountain sickness (AMS), high altitude cerebral oedema (HACE) and high altitude pulmonary oedema (HAPE) are reported as potential medical problems associated with high altitude. In this review, the first in a series of three about preventive strategies for HAI, we assess the effectiveness of six of the most recommended classes of pharmacological interventions.

OBJECTIVES

To assess the clinical effectiveness and adverse events of commonly-used pharmacological interventions for preventing acute HAI.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (OVID), Embase (OVID), LILACS and trial registries in January 2017. We adapted the MEDLINE strategy for searching the other databases. We used a combination of thesaurus-based and free-text terms to search.

SELECTION CRITERIA

We included randomized-controlled and cross-over trials conducted in any setting where commonly-used classes of drugs were used to prevent acute HAI.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane.

MAIN RESULTS

We included 64 studies (78 references) and 4547 participants in this review, and classified 12 additional studies as ongoing. A further 12 studies await classification, as we were unable to obtain the full texts. Most of the studies were conducted in high altitude mountain areas, while the rest used low pressure (hypobaric) chambers to simulate altitude exposure. Twenty-four trials provided the intervention between three and five days prior to the ascent, and 23 trials, between one and two days beforehand. Most of the included studies reached a final altitude of between 4001 and 5000 metres above sea level. Risks of bias were unclear for several domains, and a considerable number of studies did not report adverse events of the evaluated interventions. We found 26 comparisons, 15 of them comparing commonly-used drugs versus placebo. We report results for the three most important comparisons: Acetazolamide versus placebo (28 parallel studies; 2345 participants)The risk of AMS was reduced with acetazolamide (risk ratio (RR) 0.47, 95% confidence interval (CI) 0.39 to 0.56; I² = 0%; 16 studies; 2301 participants; moderate quality of evidence). No events of HAPE were reported and only one event of HACE (RR 0.32, 95% CI 0.01 to 7.48; 6 parallel studies; 1126 participants; moderate quality of evidence). Few studies reported side effects for this comparison, and they showed an increase in the risk of paraesthesia with the intake of acetazolamide (RR 5.53, 95% CI 2.81 to 10.88, I² = 60%; 5 studies, 789 participants; low quality of evidence). Budenoside versus placebo (2 parallel studies; 132 participants)Data on budenoside showed a reduction in the incidence of AMS compared with placebo (RR 0.37, 95% CI 0.23 to 0.61; I² = 0%; 2 studies, 132 participants; low quality of evidence). Studies included did not report events of HAPE or HACE, and they did not find side effects (low quality of evidence). Dexamethasone versus placebo (7 parallel studies; 205 participants)For dexamethasone, the data did not show benefits at any dosage (RR 0.60, 95% CI 0.36 to 1.00; I2 = 39%; 4 trials, 176 participants; low quality of evidence). Included studies did not report events of HAPE or HACE, and we rated the evidence about adverse events as of very low quality.

AUTHORS' CONCLUSIONS

Our assessment of the most commonly-used pharmacological interventions suggests that acetazolamide is an effective pharmacological agent to prevent acute HAI in dosages of 250 to 750 mg/day. This information is based on evidence of moderate quality. Acetazolamide is associated with an increased risk of paraesthesia, although there are few reports about other adverse events from the available evidence. The clinical benefits and harms of other pharmacological interventions such as ibuprofen, budenoside and dexamethasone are unclear. Large multicentre studies are needed for most of the pharmacological agents evaluated in this review, to evaluate their effectiveness and safety.

Findings of Cognitive Impairment at High Altitude: Relationships to Acetazolamide Use and Acute Mountain Sickness

Phillips, Lara, Buddha Basnyat, Yuchiao Chang, Erik R. Swenson, and N. Stuart Harris. Findings of cognitive impairment at high altitude: relationships to acetazolamide use and acute mountain sickness. High Alt Med Biol. 18:121-127, 2017.

OBJECTIVE

Acute mountain sickness (AMS) is defined by patient-reported symptoms using the Lake Louise Score (LLS), which provides limited insight into any possible underlying central nervous system (CNS) dysfunction. Some evidence suggests AMS might coexist with altered neural functioning. Cognitive impairment (CI) may go undetected unless a sensitive test is applied. Our hypothesis was that a standardized test for mild CI would provide an objective measure of CNS dysfunction, which may correlate with the symptoms of AMS and so provide a potential new tool to better characterize altitude-related CNS dysfunction. We compared a cognitive screening tool with the LLS to see if it correlated with CNS dysfunction.

METHODS

Adult native English-speaking subjects visiting Himalayan Rescue Association aid stations in Nepal at 3520 m (11,548 ft) and 4550 m (14,927 ft) were recruited. Subjects were administered the LLS and a slightly modified version of the environmental Quick mild cognitive impairment screen (eQmci). Medication use for altitude illness was recorded. Scores were compared using the Spearman's correlation coefficient. Data also included medication use.

RESULTS

Seventy-nine subjects were enrolled. A cut-off of three or greater was used for the LLS to diagnose AMS and 67 or less for the eQmci to diagnose CI. There were 22 (28%) subjects who met criteria for AMS and 17 (22%) subjects who met criteria for CI. There was a weak correlation (r² = 0.06, p = 0.04) between eQmci score and LLS. In matched subjects with identical LLS, recent acetazolamide use was associated with significantly more CI.

CONCLUSION

Field assessment of CI using a rapid standardized tool demonstrated that a substantial number of subjects were found to have mild CI following rapid ascent to 3520-4550 m (11,548-14,927 ft). The weak correlation between the LLS and eQmci suggests that AMS does not result in CI. Use of acetazolamide appears to be associated with CI at all levels of AMS severity.

Keratitis in six dogs after topical treatment with carbonic anhydrase inhibitors for glaucoma

CASE DESCRIPTION

6 dogs (10 eyes) with keratitis following long-term topical treatment with a carbonic anhydrase inhibitor (CAI) were evaluated. In 4 dogs (6 eyes), CAI treatment was discontinued. Three dogs (4 eyes) underwent enucleation because of end-stage corneal disease. One dog was treated differently in each eye and thus was represented in both aforementioned groups.

CLINICAL FINDINGS

Following initiation of treatment with a CAI (ie, brinzolamide or dorzolamide), the median time to development of severe ocular signs was 266 days (range, 133 to 679 days). Clinically severe ocular signs included ulcerative and nonulcerative perilimbal keratitis or severe diffuse keratitis with marked vascularization. The keratitis was refractory to treatment with anti-inflammatory medications. Histologic and immunohistochemical examination of enucleated globes was performed in 3 affected dogs and in 1 dog with keratitis that recovered. Corneal lesions included 2 distinct inflammatory infiltrates with plasma cells predominating in the anterior stroma and both T cells and neutrophils in the epithelium. Stromal plasma cells and overlying epithelium exhibited strong positive immunoreactivity for IgG.

TREATMENT AND OUTCOME

Topical CAI treatment was discontinued in 4 dogs after a median of 209 days (range, 44 to 433 days), and in these dogs, clinical improvement was evident within 2 to 4 days of CAI treatment cessation. Signs of keratitis resolved in 12 to 25 days in these 4 dogs, and median follow-up time after CAI discontinuation was 25.5 months (range, 6 to 42 months), during which time signs of corneal disease did not recur.

CLINICAL RELEVANCE

On the basis of this small series, presumed topical CAI-associated keratitis in dogs appeared to be an uncommon immune-mediated disease that was not responsive to corticosteroid treatment. Affected patients improved rapidly, but only after discontinuation of CAI treatment. In dogs with glaucoma, clinicians should consider the development of punctate keratopathy and severe diffuse keratitis as potential adverse effects related to topical administration of CAIs, even after previously uneventful long-term use.

Research on Susceptible Genes and Immunological Pathogenesis of Cutaneous Adverse Drug Reactions in Chinese Hans

Cutaneous adverse drug reactions (cADRs) include mild maculopapular exanthems (MPE), Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS) and acute generalized exanthematous pustulosis (AGEP). We used HLA high-resolution genotyping and genome wide association analysis (GWAS) to identify the genetic markers for cADRs induced by common culprit drugs in Han Chinese population. To further understand the immunopathogenesis of cADRs, and with the goal of developing treatment strategies, we compared the expression of cytoxic cytokines between the patients with cADRs and normal controls. Our data suggested that the carbamazepine induced SJS/TEN, allopurinol induced CADRs, methazolamide induced SJS/TEN and SASP induced DRESS were respectively strongly associated with HLA-B*15:02, HLA-B*58:01, HLA-B*59:01 and HLA-B*13:01. In addition, increased expression of cytotoxic cytokines in sera and tissues of cADRs patients were found, compared with healthy controls. Our findings may shed light on prediction and prevention of cADRs, provide clues to pathogenesis, and guide treatment strategies of these reactions.

Acetazolamide and prevention of acute mountain sickness

When planning a rapid ascent to an altitude above 3000 metres, acetazolamide 250 mg daily reduces the risk of acute mountain sickness, with generally moderate adverse effects.

Evaluation of adverse events in self-reported sulfa-allergic patients using topical carbonic anhydrase inhibitors

PURPOSE

To investigate whether a self-reported history of allergy to sulfa-based drugs is a predictor for subsequent adverse reactions to topical carbonic anhydrase inhibitors (CAIs).

METHODS

A retrospective case-controlled cohort study via chart review was performed on 1,287 patients with a diagnosis of glaucoma. The outcome measure was the development of an adverse reaction (either ocular, systemic, or both) within at least 30 days after receipt of 1 of 4 classes of topical glaucoma medications: CAIs (dorzolamide and brinzolamide), prostaglandin analogues, beta-adrenergic blockers, and alpha2-adrenergic agonists.

RESULTS

Patients with a self-reported history of sulfa allergy had significantly more ocular adverse reactions after the initiation of any of the topical antiglaucoma medications when compared to those patients with no reported allergies. Patients with a self-reported sulfa allergy and patients who self-reported other, nonsulfa-related allergies had similar rates of adverse reactions to most of the topical medications. The patients reporting a sulfa allergy who used topical CAIs did not have more adverse reactions compared with patients who reported having other, nonsulfa-related allergies who used topical CAIs. Self-reported sulfa-allergic patients had similar rates of adverse reactions to topical CAIs compared with topical prostaglandin analogues.

CONCLUSION

It may be safe to use a topical CAI in patients who report a history of a sulfa allergy. Patients with medication allergies of any kind may be more likely to develop allergic reactions to other, unrelated drug classes.

Identifying the lowest effective dose of acetazolamide for the prophylaxis of acute mountain sickness: systematic review and meta-analysis

OBJECTIVES

To assess the efficacy of three different daily doses of acetazolamide in the prevention of acute mountain sickness and to determine the lowest effective dose.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline and Embase along with a hand search of selected bibliographies. No language restrictions were applied.

STUDY SELECTION

Randomised controlled trials assessing the use of acetazolamide at 250 mg, 500 mg, or 750 mg daily versus placebo in adults as a drug intervention for the prophylaxis of acute mountain sickness. Included studies were required to state the administered dose of acetazolamide and to randomise participants before ascent to either acetazolamide or placebo. Two reviewers independently carried out the selection process.

DATA EXTRACTION

Two reviewers extracted data concerning study methods, pharmacological intervention with acetazolamide, method of assessment of acute mountain sickness, and event rates in both control and intervention groups, which were verified and analysed by the review team collaboratively.

DATA SYNTHESIS

11 studies (with 12 interventions arms) were included in the review. Acetazolamide at doses of 250 mg, 500 mg, and 750 mg were all effective in preventing acute mountain sickness above 3000 m, with a combined odds ratio of 0.36 (95% confidence interval 0.28 to 0.46). At a dose of 250 mg daily the number needed to treat for acetazolamide to prevent acute mountain sickness was 6 (95% confidence interval 5 to 11). Heterogeneity ranged from I(2)=0% (500 mg subgroup) to I(2)=44% (750 mg subgroup).

CONCLUSIONS

Acetazolamide in doses of 250 mg, 500 mg, and 750 mg daily are all more effective than placebo for preventing acute mountain sickness. Acetazolamide 250 mg daily is the lowest effective dose to prevent acute mountain sickness for which evidence is available.

[Clinical strategies for prevention of drug-induced urinary calculi]

Drug-induced urinary calculi, although they account for only 1-2% of urinary calculi, deserve consideration because most of them are preventable. In the drug-containing calculi resulting from the crystallization of a certain drug and its metabolites in the urine, stone analysis can identify the responsible drug. While, in the drug-induced metabolic calculi caused by interference with calcium, oxalate and purine metabolism, careful clinical inquiry is necessary to reveal involvement of a certain drug in stone formation. Better awareness of the possible drugs with lithogenic potential and close surveillance of patients on long-term treatment with these drugs are necessary. Especially, in patients with a history of urolithiaisis, prescription of lithogenic drugs deserve careful consideration.

Brinzolamide 1%/timolol 0.5%: safety and efficacy of a new fixed-combination IOP-lowering product for glaucoma

OBJECTIVE

To provide a commentary on recent studies with the new IOP-lowering fixed-combination product brinzolamide 1%/timolol 0.5%.

METHODS

Medline was searched for brinzolamide/timolol fixed-combination clinical literature (up to May 18, 2010) and the current comprehensive brinzolamide/timolol literature was reviewed.

RESULTS

Compared with another carbonic anhydrase inhibitor-containing product, dorzolamide 2%/timolol 0.5%, brinzolamide/timolol has similar IOP-lowering efficacy. Brinzolamide/timolol also produces superior comfort ratings as assessed by patients who have tried both drugs - this may be explained by the more physiologic pH of brinzolamide/timolol. A recent study reported that brinzolamide/timolol was preferred over dorzolamide/timolol at a ratio of nearly 4:1 among those expressing a preference.

CONCLUSION

These results demonstrate that brinzolamide/timolol is equally effective and more comfortable than dorzolamide/timolol, a fact that may positively impact patient adherence, leading to an increased likelihood of reaching target IOP goals.

[Mechanism of blurred vision after brinzolamide instillation]

PURPOSE

Eye drops of carbonic anhydrase inhibitor (Brinzolamide) are known to case blurred vision after instillation. Using tear film stability analysis system (TSAS) and functional visual acuity measurement (FVAM) we studied the mechanism of blurred vision.

METHODS

Ten healthy volunteers were studied. Before instillation of brinzolamide 1%, immediately after and at 3, 5, 10 minutes after 1 minutes eye-closure after instillation the breakup index (BUI) of TSAS and FVAM were measured.

RESULTS

Before instillation of brinzolamide 1%, immediately after and at 3, 5, 10 minutes since 1 minutes eye-closure after instillation the BUI of TSAS was 88.3 +/- 1.2, 38.5 +/- 7, 72.1 +/- 4.2, 78.8 +/- 5.1, 83.7 +/- 2.2 respectively, and the FVAM was 1.013 +/- 0.0047, 0.925 +/- 0.029, 1 +/- 0.0075, 1.007 +/- 0.0072, 1.015 +/- 0.0052 respectively. Immediately after 1 minutes eye-closure both BUI and FVAM were low. From 3 minutes after instillation both BUI and FVAM recovered.

CONCLUSIONS

It is suggested that blurred vision after instillation of brinzolamide 1% is associated with the unstableness of tear film. Analyses by TSAS and FVAM are useful to determine both the vision improvement and pharmacokinetics after instillation.

Medical management of angle closure glaucoma

Management of angle closure glaucoma requires an understanding of the underlying pathophysiologic mechanisms. Treatment is aimed at eliminating pupillary block and other causes of angle closure, re-opening the angle, and preventing further damage to the optic nerve by lowering intraocular pressure. Medical therapy plays an important role in the successful management of this condition. This article describes commonly used pharmacologic agents, as well as newer classes of drugs such as topical carbonic anhydrase inhibitors, prostaglandin analogues and selective alpha2- adrenergic agonists. Use of these drugs in several clinically distinct angle closure syndromes and modes of presentation are discussed.

Acetazolamide as an adjunct to CPAP treatment: a case of complex sleep apnea in a patient on long-acting opioid therapy

A 41-year-old white woman on long-acting opioid therapy was diagnosed with moderate obstructive sleep apnea. On initiation of continuous positive airway pressure (CPAP), she manifested severe central apnea that was unresponsive to supplemental oxygen and interfered with CPAP titration. Acetazolamide, 250 mg, nightly at bedtime was initiated, and CPAP titration was repeated. On acetazolamide, optimal CPAP pressure was obtained with no manifestation of clinically significant central respiratory disturbance. This case suggests that acetazolamide may be an effective adjunct to positive airway pressure therapy in patients on long-acting opioids. A need exists for examination of acetazolamide in this capacity.

The impact of common classes of topical antiglaucoma medications on central corneal thickness--own observations

PURPOSE

To investigate the influence of common classes of topical antiglaucoma medications used either in monotherapy or combined therapy on CCT.

MATERIAL AND METHODS

In a retrospective study 487 eyes from consecutive 260 patients (148 F/112 M) with open angle glaucoma were examined. Depending on the topical treatment they were classified into 7 groups: A/PGA (n=212), B/BB (n= 54), C/CAI (n=36), D/PGA + CAI (n=25) E/PGA + BB (n=23) F/BB + CAI (n=54), G/ non-treated (n=83). The CCT was measured using ultrasound pachymetry Tomey AL-2000. The central corneal power was measured with the Topcon keratometer. ANOVA analyses were used for statistical analysis.

RESULTS

There were no statistically significant differences between CCT of all groups (F = 1.06, p = 0.3931); the lowest values were in the eyes treated with PGA + BB (535.9 microm SD 31.4) and the highest in the eyes treated with PGA + CAI (571.3 microm SD 46.3). The Mean CCT in group A was 550.4 microm (SD 40.8), group B 552.5 microm (SD 34.7), group C 562.6 microm (SD 40.2), group D 571.3 microm (SD 46.3), group E 535.9 microm (SD 31.4), group F 559.5 microm (SD 32.5), group F 557.5 microm (SD 42.2). There were no statistically significant differences between CCT of eyes treated with different PGA. The highest CCT was found in the eyes treated with bimatoprost (554.4 microm SD 46.0) and the lowest in the eyes treated with latanoprost (546.4 microm SD 37.7).

CONCLUSIONS

In this study CCT appears not to differ in eyes treated with different classes of antiglaucoma medications either in monotherapy or combined therapy. CCT appears not to differ in eyes treated with different prostaglandin and prostamide anal logs. CCT of treated glaucoma eyes does not differ from CCT of untreated glaucoma eyes.

Dermite de contact et acétazolamide par voie topique sous occlusion

INTRODUCTION

Acetazolamide is a carbonic anhydrase inhibitor used topically for local secondary treatment of posttraumatic or postoperative edema.

CASES

Two women had contact dermatitis, secondarily extensive, after local cutaneous use of acetazolamide under a compression panty after liposuction. The eruption disappeared after acetazolamide was stopped and local treatment administered. Cutaneous tests were positive for acetazolamide.

DISCUSSION

Local allergic reactions are mentioned in the monograph on topical acetazolamide. Cases of contact dermatitis from this drug have not so far been published, but French adverse drug reaction reporting data include 10 other cases of eczema or rash at the application site. In one of these, a positive reaction was observed on readministration, and in 2 cases allergy skin tests were positive. The application of the drug under occlusion, which is contraindicated, may have contributed to spreading the lesions. Cases have also been described with another carbonic anhydrase inhibitor, dorzolamide, used in ophthalmology.

Treatment of idiopathic intracranial hypertension: topiramate vs acetazolamide, an open-label study

OBJECTIVES - To assess the efficacy of topiramate in the treatment of idiopathic intracranial hypertension (IIH) and to compare it with acetazolamide. METHODS - Fourty patients diagnosed as IIH and randomly assigned to treatment with either acetazolamide or topiramate were assessed prospectively. Improvement in the visual fields at the end of third, sixth and twelfth months were taken into consideration. RESULTS - The demographic, clinical features and the cerebrospinal fluid (CSF) pressure of the two treatment groups were similar at the beginning of the study. When the follow-up visual field grades were compared with the visual field grades at the beginning of the study in each group a statistically significant improvement was detected with both drugs. When the results of the two treatment groups were compared with each other no statistically significant difference was present. Prominent weight loss was recorded in the topiramate group. CONCLUSIONS - Topiramate seems to be effective in the treatment of IIH. Weight reduction as well as the reduction of the CSF formation is the possible mechanism of action.

[Ultrastructural evaluation of mitomycin C toxic effects on the ciliary epithelium of normal rabbits eyes with and without aqueous humor suppressant treatment]

PURPOSE

To evaluate the effects of mitomycin C (MMC) on the internal ciliary epithelium (ICE) of the ciliary body of animals treated with two different aqueous humor suppressants.

METHODS

The eyes of sixteen Norfolk albino rabbits divided into four experimental groups were studied. The right eyes (RE) of the four groups received 0.1 ml of MMC (0.5 mg/ml) under the scleral flap. The left eyes (LE) was the control group. Group 1 (G1) did not have any other treatment. To Group 2 (G2) and Group 4 (G4) acetazolamide was administered. To Group (G3) and Group 4 (G4) timolol maleate was administered. ICE was examined by transmission electron microscopy (TEM).

RESULTS

The following aspects were observed in all groups, except in G1 LE: cell shrinkage and/or enlargement of intercellular spaces, rarefied mitochondria, clear vesicular structures and electron-dense bodies. The internal limitant membrane showed to be thickened, discontinued and separated in all groups, except in G1 LE and G2 LE. Discharge of cytoplasmatic material was observed only in the groups treated with aqueous humor suppressants.

CONCLUSIONS

1) MMC, acetazolamide and timolol maleate caused morphological alterations in the ciliary epithelium even when used alone. 2) The combination of MMC and acetazolamide caused more alterations than did isolated acetazolamide, but not more than MMC alone. 3) For the other combinations the alterations were similar.

Cerebral fat embolism syndrome causing brain death after long-bone fractures and acetazolamide therapy

A 19-year-old woman with multiple fractures and mild brain injury developed severe cerebral fat embolism syndrome after "damage control" orthopaedic surgery. Acetazolamide therapy to manage ocular trauma, in association with hyperchloraemia, caused a profound metabolic acidosis with appropriate compensatory hypocapnia. During ventilator weaning, unexpected brainstem coning followed increased sedation and brief normalisation of arterial carbon dioxide concentration. Autopsy found severe cerebral fat embolism and brain oedema. In patients with multiple trauma, cerebral fat embolism syndrome is difficult to diagnose, and may be more common after delayed fixation of long-bone fractures. Acetazolamide should be used with caution, as sudden restoration of normocapnia during compensated metabolic acidosis in patients with raised intracranial pressure may precipitate coning.

The Development of Topically Acting Carbonic Anhydrase Inhibitors as Antiglaucoma Agents

Carbonic anhydrase inhibitors (CAIs) such as acetazolamide, methazolamide, ethoxzolamide and dichlorophenamide were and still are widely used systemic antiglaucoma drugs. Their mechanism of action consists in inhibition of CA isozymes present in ciliary processes of the eye (such as CA II, IV and XII), with the consequent reduction of bicarbonate and aqueous humour secretion, and of elevated intraocular pressure (IOP) characteristic of this disease. Since CA II/IV/XII are present in many other tissues/organs, generally, systemic CAIs possess undesired side effects such as numbness and tingling of extremities; metallic taste; depression; fatigue; malaise; weight loss; decreased libido; gastrointestinal irritation; metabolic acidosis; renal calculi and transient myopia. In order to avoid these undesired side effects, recently, topically effective CAIs have been developed. Two drugs are available clinically: dorzolamide and brinzolamide. Both these drugs are applied topically as water solutions/suspensions, alone or in combination with other agents (such as beta-blockers, prostaglandin derivatives, etc) and produce a consistent and prolonged reduction of IOP. Furthermore, recent reports show both the systemically as well as topically acting sulfonamide CAIs to be effective in the treatment of macular oedema and other macular degeneration diseases, for which pharmacological treatment was unavailable up to now. Much research is in act in the search of even more effective topically acting CAIs, free of the inconveniences and side effects of the presently available drugs. For achieving this goal, a recently reported strategy, the tail approach, was extensively applied for the synthesis of large numbers of derivatives possessing various physico-chemical properties. Many such new sulfonamides showed promising antiglaucoma activity in animal models of the disease.

Hypotony and choroidal detachment as a complication of topical combined timolol and dorzolamide

PURPOSE

Hypotony with choroidal detachment is a rare complication of glaucoma medication. In this study, we report on a case which supports the hypothesis that has been proposed to explain this phenomenon.

DESIGN

This study was designed as an observational case report.

CASE REPORT

A woman with chronic glaucoma underwent trabeculectomy on both eyes. Low intraocular pressure (IOP) developed in 1 eye only, with no visual change for many years. After cataract surgery, the IOP increased, necessitating treatment with topical timolol 0.5% and dorzolamide 2%. She developed monocular hypotony and choroidal detachment 3 months later. This complication occurred in the eye that had previously had a low IOP and resolved completely when topical medication was stopped. The choroidal detachment recurred when rechallenged with the same medication.

CONCLUSIONS

Topical aqueous suppression therapy can result in hypotony and choroidal detachment in an eye in which relatively low IOP has been maintained for many years after glaucoma filtration surgery. The problem resolves on stopping the medication.

[Ocular side effects of glaucoma treatment agents]

Antiglaucomatous ocular side effects can be divided into specific and non specific ones. Non specific ocular side effects are mainly caused by preservative agents; they are essentially external ocular irritations. Specific ocular side effects are strongly related to the mechanism of action of the drug. These specific ocular side effects are described, caution being taken to precise the strength of the association between each side effect and the related drug by using the classification of World Health Organisation (WHO) (certain, probable, possible or unlikely).

Comparative efficacy of acetazolamide and apraclonidine in the control of intraocular pressure following phacoemulsification

PURPOSE

The purpose of our study was to compare the effects of systemically administered acetazolamide and topical apraclonidine 0.5% in the control of intraocular pressure (IOP) following phacoemulsification of senile cataracts.

SETTING

The study was conducted on patients affected by cataract and followed at the Department of Ophthalmology.

METHODS

Seventy-eight eyes in 78 patients were selected. Twenty-six eyes were randomly assigned to postoperative treatment with topical apraclonidine 0.5%, 26 received oral acetazolamide and the remaining 26 received no hypotensive treatment (control group). Statistical analyses were performed mainly by means of analyis of variance.

RESULTS

IOPs measured 24 h after surgery were significantly (p = 0.01) lower in the apraclonidine group compared to the control group.

CONCLUSIONS

Our double-blind prospective study conducted on patients randomly assigned to treatment with apraclonidine or acetazolamide shows that the former drug is undoubtedly effective in the prevention of IOP increases following phacoemulsification. IOPs recorded in patients treated with this drug were lower than those observed in the acetazolamide and the control groups. Considering the lower risk of toxicity associated with topical administration, apraclonidine 0.5% seems to be preferable to oral acetazolamide in this postoperative setting.

Effects of the selective cyclooxygenase-2 inhibitor analgesic celecoxib on renal carbonic anhydrase enzyme activity: a randomized, controlled trial

Rofecoxib and celecoxib were the first cyclooxygenase-2 (COX-2)-specific inhibitors to be marketed as effective anti inflammatory agents. The results of several recent trials and a meta analysis of currently available studies all demonstrate a greater incidence of increased blood pressure, edema, and cardiovascular events in subjects treated with rofecoxib compared with celecoxib. As an approach to the assessment of molecular mechanisms that may contribute to these cardiorenal differences, this study investigated the inhibitory effects of celecoxib on renal carbonic anhydrase enzyme activity in human hypertensive subjects because in vitro enzyme studies demonstrate such an effect. Ten subjects with stable, treated hypertension were randomized to 1 of 3 treatment sequences, which included, in differing order, 200 mg celecoxib twice a day, 250 mg acetazolamide twice a day, or placebo twice a day. Whereas acetazolamide caused a bicarbonate diuresis and a hyperchloremic metabolic acidosis, celecoxib appeared to have no detectable effect on renal carbonic anhydrase or acid-base homeostasis. Thus, in this short-term study of human subjects, therapeutic doses of celecoxib did not appear to have a clinically significant inhibitory action on renal carbonic anhydrase.