The effect of systemic acetazolamide administration on intraocular pressure in healthy horses-A preliminary study.
Abstract: In equine glaucoma, topical treatment with carbonic anhydrase inhibitors (CAIs) is recommended. Oral acetazolamide, a systemic CAI, is used in horses with hyperkalemic periodic paralysis. Information regarding its effect on equine intraocular pressure (IOP) is scarce. The aim of the study was to determine the effect of oral acetazolamide treatment on IOP in horses, in a case-control study. Methods: Ten healthy horses. Methods: Horses were treated with oral acetazolamide (4.4 mg/kg) BID for 1 week. Serum acetazolamide concentrations were determined by liquid chromatography/tandem mass spectrometry, and IOP were measured before treatment, daily during treatment, and at 48 and 72 h after treatment. Results: Acetazolamide serum levels reached steady state at 72 h after the first oral dose. In a mixed effect model logistic regression, there was a significant decrease in IOP on the third treatment day, of 2.4 mmHg (p = .012) and 2.7 mmHg (p = .006) in the left (OS) and right eye (OD), respectively. On the seventh day, there was a decrease in 2.5 mmHg (p = .008) and 2.7 mmHg (p = .007) OS and OD, respectively. A significant increase occurred 48 h following treatment discontinuation (3.6 mmHg, p < .001 and 3.5 mmHg, p < .001 OS and OD, respectively). The area under the concentration versus time curve (AUC(0-10h)) was 1.1 ± 0.5 μg/mL*h, mean residence time 6.7 ± 4.3 h, peak plasma concentration (Cmax) 0.4 ± 0.4 μg/mL and time to reach Cmax 1.8 h. There was a significant increase in serum concentrations 1, 2, 48, 72, and 156 h following the first drug administration (p < .05). Conclusions: Further studies are required to determine whether acetazolamide is a potential treatment for equine glaucoma.
© 2024 The Author(s). Veterinary Ophthalmology published by Wiley Periodicals LLC on behalf of American College of Veterinary Ophthalmologists.
Publication Date: 2024-06-05 PubMed ID: 38839562PubMed Central: PMC11773671DOI: 10.1111/vop.13240Google Scholar: Lookup
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- Journal Article
- Clinical Trial
- Veterinary
Summary
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This research investigated the impact of an oral medication called acetazolamide on eye pressure in healthy horses, as part of preliminary research towards potential new treatments for equine glaucoma.
Study Overview
The study aimed to evaluate the effects of acetazolamide, a medication that inhibits an enzyme called carbonic anhydrase, on horses’ intraocular pressure (IOP). The drug is commonly used in horses suffering from hyperkalemic periodic paralysis, a muscle disorder. This was a case-control study using healthy horses. Observations of changes in IOP could provide insights into potential treatments for equine glaucoma, a condition where increased IOP can lead to vision loss.
- Ten healthy horses participated in the study.
- Horses received acetazolamide orally at a dose of 4.4 mg/kg, twice daily for a week.
- Acetazolamide levels in serum were established using liquid chromatography/tandem mass spectrometry.
- The horses’ IOP was measured before treatment, daily throughout treatment, and at 48 and 72 hours after treatment.
Results
The levels of acetazolamide in serum reached a constant level, often referred to as steady-state, 72 hours after the first oral dose. The study found significant decreases in IOP in both eyes on the third and seventh days of treatment.
- On the third day of treatment, IOP decreased by 2.4 mmHg in the left eye and 2.7 mmHg in the right eye.
- On the seventh day, reductions of 2.5 mmHg and 2.7 mmHg in IOP were observed in the left and the right eye, respectively.
- A significant increase in IOP, by 3.6 and 3.5 mmHg in the left and right eyes respectively, occurred 48 hours after the treatment was discontinued.
Pharmacokinetic observations showed the time by which the peak plasma concentration was reached was typically 1.8 hours, while the mean residence time (the average time the drug remains in the body before being eliminated) was approximately 6.7 hours.
Conclusion
While the study indicates that acetazolamide had a significant effect on the IOP of healthy horses, further research is required to assess its potential as a viable treatment for equine glaucoma. It is important to bear in mind that this was a preliminary study with a small sample size, providing a baseline for future, more comprehensive studies.
Cite This Article
APA
Shnaiderman-Torban A, Pe'er O, Gustafsson K, Tatz A, Brizi M, Soback S, Abu Ahmad W, Magen R, Ofri R, Kelmer G.
(2024).
The effect of systemic acetazolamide administration on intraocular pressure in healthy horses-A preliminary study.
Vet Ophthalmol, 28(1), 66-72.
https://doi.org/10.1111/vop.13240 Publication
Researcher Affiliations
- Koret School of Veterinary Medicine (KSVM), The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
- Koret School of Veterinary Medicine (KSVM), The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
- Koret School of Veterinary Medicine (KSVM), The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
- Department of Veterinay Medicine and Animal Sciences, University of Milan, Lodi, Italy.
- Koret School of Veterinary Medicine (KSVM), The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
- Kimron Veterinary Institute, Bet Dagan, Israel.
- Kimron Veterinary Institute, Bet Dagan, Israel.
- Hadassah Braun School of Public Health and Community Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel.
- Koret School of Veterinary Medicine (KSVM), The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
- Koret School of Veterinary Medicine (KSVM), The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
- Koret School of Veterinary Medicine (KSVM), The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
MeSH Terms
- Animals
- Horses
- Acetazolamide / administration & dosage
- Acetazolamide / pharmacology
- Acetazolamide / blood
- Acetazolamide / pharmacokinetics
- Intraocular Pressure / drug effects
- Carbonic Anhydrase Inhibitors / administration & dosage
- Carbonic Anhydrase Inhibitors / pharmacology
- Carbonic Anhydrase Inhibitors / pharmacokinetics
- Carbonic Anhydrase Inhibitors / blood
- Male
- Female
- Case-Control Studies
- Administration, Oral
- Horse Diseases / drug therapy
Conflict of Interest Statement
None.
References
This article includes 16 references
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