Day of Ascent Dosing of Acetazolamide for Prevention of Acute Mountain Sickness.

Background: Acetazolamide is the most common medication used for prevention of acute mountain sickness (AMS), usually administered the day or night before ascent. The objective of this study was to evaluate the efficacy of day of ascent dosing of acetazolamide for AMS prevention. Methods: Double-blind, randomized, controlled noninferiority trial of acetazolamide 125 mg twice daily beginning either the night before or the morning of ascent. Healthy low altitude adults ascended from 1240 m (4100 ft) to 3810 m (12,570 ft) during summer 2018 on White Mountain, California. Primary outcome was incidence of AMS with the two different dosing patterns, assessed by the 1993 Lake Louise Questionnaire (LLQ) of ≥3 with headache and a minimum of 1 for other symptom. Results: One hundred four participants completed the study, with 54 (52%) randomized to night before acetazolamide and 50 (48%) to day of ascent dosing, without differences in baseline characteristics. There was 9% greater incidence of AMS in the day of ascent acetazolamide group (48.0% vs. 39%, 95% confidence interval [CI] -11.8 to 30, p = 0.46, number needed to treat [NNT] = 5.6 vs. 3.7), with the CI just surpassing the predetermined 26% noninferiority margin. There was a lower incidence of severe AMS (1993 LLQ >5) in the day of ascent group (n = 5, 10%, NNT = 2.3) compared with night before dosing (n = 12, 22%, NNT = 3.1) (95% CI -28 to 3.6), and lower average symptom severity in the day of ascent group (3 vs. 3.5, 95% CI -0.5 to 1.4). Conclusions: Day of ascent acetazolamide demonstrated higher rates of AMS compared with traditional dosing by a small margin. With similar rates of severe AMS and overall symptom severity, the potential for improved convenience and compliance may support day of ascent use.

Oculohypotensive effects of various acetozolamide nanopreparations for topical treatment of animal model-induced glaucoma and their impact on optic nerve.

Acetozolamide-ACZ, carbonic anhydrase inhibitor- is still the most effective systemic drug for glaucoma treatment. Due to its limited ocular bioavailability, topical formulations are not available yet. This study introduces within the framework of nanotechnology three nanopreparations of acetozolamide for topical application, one of them is liposomal phospholipid vehicle and the other two preparations are propolis and Punica granatum (pomegranate). The hypotensive effect of these different nanopreparations in lowering the increased intraocular pressure that was induced in experimental rabbits is monitored for 130 hrs. Structural characteristics of the optic nerve dissected from all involved groups were studied by Fourier transfrom infrared spectroscopy. The obtained results indicate the impact of the topically applied acetozolamide nanopreparations in lowering the intraocular pressure to its normotensive control value. On the other hand, the optic nerve characteristics were found to be dependent on the way acetozolamide introduced. Glaucoma affects structural components that contain OH group and increases ß-turns of the protein secondary structure while, reducing the content of both α-helix and Turns. In the same context, liposomal-acetozolamide and propolis nanopreparations protecting the optic nerve protein secondary structure from these changes associated with glaucoma.

Treatment of hypokalemic periodic paralysis with topiramate.

Hypokalemic periodic paralysis (hypoPP), the most common form of periodic paralysis, is a disorder characterized by attacks of transient muscle weakness associated with a drop in serum potassium level.The mainstay of treatment is potassium supplementation and drugs that inhibit the enzyme carbonic anhydrase. In this report we describe 11-year-old twins with hypoPP who were treated with topiramate, an anti-epileptic drug known to have carbonic anhydrase inhibitory properties. The patients experienced a decrease in the severity of their attacks upon initiation of treatment. Topiramate may warrant further investigation as a treatment option in hypoPP.

Bidirectional influences of acetazolamide on central nervous system oxygen toxicity of rats.

Central nervous system oxygen toxicity, which occurs during diving and hyperbaric oxygen treatment, can lead to very dangerous situations, and it is of great importance to explore its mechanisms. We have speculated that cerebral blood flow plays a pivotal role in its occurrence. Except for acting as an anticonvulsant in clinical applications, acetazolamide is also a vasodilator used in both clinical and laboratory settings. In this study, when acetazolamide from 5 to 500 ug/kg body weight was administered by intracerebroventricular injection, the latency of central nervous system oxygen toxicity detected by electroencephalogram recording in rats subjected to hyperbaric oxygen at 6 atmospheres absolute was prolonged significantly. On the contrary, when the dose of intracerebroventricular injection achieved 5,000 ug/kg body weight, acetazolamide shortened the latency significantly. Intraperitoneal injection of acetazolamide more than 7.5 mg/kg body weight also shortened the latency significantly. Results also showed both intracerebroventricular injection of acetazolamide at a dose of 5,000 ug/kg body weight and intraperitoneal injection at dose of 7.5 mg/kg body weight inhibited the activity of carbonic anhydrase and increased the cerebral blood flow significantly, which helped aggravate oxidation damage and resulted in increased MDA and impaired glutathione peroxidase in brain tissue. But intracerebroventricular injection of acetazolamide at 5 ug/kg body weight had no effect on MDA and glutathione peroxidase, though it inhibited the activity of carbonic anhydrase. These observations indicated acetazolamide covers bidirectional influences on central nervous system oxygen toxicity. Within local brain tissue, especially neurons, it could exert its anticonvulsive effect on the central nervous system at low doses. On the other hand, under high doses, it would display its convulsive-hastening effect through increasing cerebral blood flow to aggravate the oxidation state of brain tissues and exacerbate central nervous system oxygen toxicity when subjected to hyperbaric oxygen. Blood flow of brain plays a pivotal role in central nervous system oxygen toxicity.

[The circadian effects of antiglaucomatous drugs]. / Effets nycthéméraux des molécules anti-glaucomateuses.

PURPOSE: To collect data reflecting the current knowledge on the interactions of medical antiglaucomatous therapy and circadian variations. METHOD: Review of the available literature published on this topic in common electronic databases. RESULTS: The IOP-reducing effect of a molecule throughout the day depends on many parameters and still remains poorly investigated. It is well known that beta-blockers have a poor efficacy at night, while prostaglandins prevent nocturnal IOP variations because of their original mechanism. DISCUSSION: The lack of a 24-hour IOP recording device limits our ability to track the effect of antiglaucomatous drugs over 24 hours, an important point because these antiglaucomatous drugs vary in terms of their capacity to reduce IOP over a 24-hour period. CONCLUSION: Assessing the effect of antiglaucomatous therapy on a 24-hour basis remains very difficult. However, in the next few Years, this could become an emerging focus point in the management of glaucoma.

[A differentiated approach to the treatment of normal-pressure glaucoma]. / O differentsirovannom podkhode k lecheniiu glaukomy s normal'nym davleniem.

Seventy patients with normal pressure glaucoma (NPG) were treated on the differential basis with respect to a pathogenetic disease type. The suggested complex therapy of the ischemic variation improves both the microcirculation in the optic nerve disk (OND) by administering different-effect drugs in long courses and the systemic hemodynamics (practitioners of needed skills are involved). The use of local antihypertensive drug to reduce the intraocular pressure to an individual tolerable value is important in the treatment of patients with tension-ischemic glaucoma. The process stabilized in 75.8 +/- 3.9% of patients in the main group and in 47 +/- 8.5% of patients in the control group (p < 0.05) after a follow-up of up to 2.5 years.

The effects of topical and general anesthesia on ocular drug levels and intraocular pressure lowering activity of topically applied carbonic anhydrase inhibitors.

Treatment with topical anesthetics was reported to increase corneal permeability and improve ocular drug bioavailability. These changes were attributed to the loss of reflex blinking, reduction of tear secretion and appearance of superficial corneal epithelial lesions. A recent report showed that pretreatment with Ophthetic (0.5% proparacaine HCl) (OPH) in pentobarbital-anesthetized rabbits significantly increased the permeability of the lipophobic carbonic anhydrase inhibitor (CAI) benzolamide (B) and transformed it to a highly active ocular hypotensive drug. This did not affect the permeability and activity of other, more lipophilic, CAI like methazolamide and ethoxzolamide (E). Similar experiments in awake rabbits using other CAI failed to reproduce the finding reported for B. We compared the ocular drug levels and the intraocular pressure lowering (delta IOP) with and without application of Ophthetic prior to 1 drop of 2% suspensions, in groups of anesthetized and conscious albino rabbits. In unanesthetized rabbits pretreatment with Ophthetic, lidocaine or benzalkonium had minimal and insignificant effects on ocular drug levels and delta IOP of B as well as E. On the other hand, Ophthetic or lidocaine pretreatment in anesthetized rabbits led to a highly significant increase in both ocular drug levels and hypotensive activity of B. We conclude that the error introduced by pretreatment with OPH occurs only in the presence of pentobarbital anesthesia and has little relevance to the normal, unanesthetized condition.

Acute and chronic acetazolamide administration in DBA and C57 mice: effects of age.

The clinical utility of the carbonic anhydrase (CA) inhibitor acetazolamide (ACTZ) is limited because of rapid development of tolerance to its effects. Tolerance is thought to develop as a result of glial cell proliferation and/or increased CA synthesis. DBA mice, susceptible to audiogenic seizures (AGSs) in an age-dependent manner, have increased CA activity as compared with C57 (non-audiogenic seizure susceptible) mice at 21 and 110 days of age. The present work utilized ACTZ to help determine the relationship between increased CA activity in brain and AGSs in DBA mice. Also, minimal electroshock seizure threshold (EST) was measured at various ages in DBA and C57 mice to determine age-related changes in CNS excitability. EST was significantly lower in DBA as compared with C57 mice at 18 days and between 40 and 115 days of age, suggesting that DBA mice remain hyperexcitable to electrical stimulation after they develop resistance to AGSs. ACTZ ED50s against maximal electroshock seizures (MES) were significantly higher in DBA as compared with C57 mice at 26,36, and 115 days of age. This finding correlates with higher CA activity in this strain at 110 days of age, noted previously. However, at 21 days of age, when CA activity is also higher in DBA versus C57 mice, there were no significant differences in ACTZ ED50s against MES between the strains. ACTZ ED50s against AGSs in DBA mice were considerably lower than ACTZ ED50s against MES in either strain, suggesting that a particular fraction of CA is intimately involved in the production of AGSs.(ABSTRACT TRUNCATED AT 250 WORDS)