The effects of orally administered trazodone on ambulation and recumbency in healthy horses.
Abstract: Trazodone, a serotonin receptor antagonist and reuptake inhibitor, might be a useful adjunctive treatment in the initial management of horses with acute laminitis if it minimizes ambulation or encourages recumbency. Objective: (1) Evaluate the effects of PO trazodone on ambulatory activity and recumbency in healthy horses; and (2) assess the pharmacokinetics of multiple PO doses of trazodone. Methods: In a randomized cross-over design, 8 healthy horses received placebo or trazodone at 2 doses (2.5 and 7.5 mg/kg) PO q12h for 48 hours with a 14-day washout period between treatments. Forelimb step frequency was measured using a hoof-mounted accelerometer and continuous video monitoring was used to detect recumbency. Groups were compared using repeated measures analysis of variance with Tukey's post hoc test. Trazodone and m-chlorophenylpiperazine (m-CPP) plasma concentrations were determined by ultra-high performance liquid chromatography-tandem mass spectrometry and pharmacokinetics were analyzed using noncompartmental methods. Results: Step frequency was lower in horses receiving 7.5 mg/kg trazodone than in the control group (mean step reduction: 44% ± 11%). Steps-area under the curve were significantly lower in the 7.5 mg/kg group (mean ± SD: 3375 ± 525 steps × hour) as compared to the 2.5 mg/kg group (mean ± SD: 5901 ± 2232; P = .02) and compared to control (mean ± SD: 6590 ± 1241; P = .001). No difference was found in the number of recumbent episodes (P = .92) or total duration of recumbency (P = .9). Trazodone and m-CPP achieved steady-state concentrations, with an accumulation ratio of 1.45 ± 0.2. Conclusions: Although it did not affect recumbency, trazodone at 7.5 mg/kg q12h decreased step frequency by approximately 44%.
© 2023 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.
Publication Date: 2023-07-25 PubMed ID: 37489582DOI: 10.1111/jvim.16821Google Scholar: Lookup
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Summary
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This study explored whether giving horses a drug called Trazodone could make them move less and lie down more, which could help treat a painful foot condition. The drug reduced the horses’ steps but didn’t make them lie down more.
Background
- Trazodone is a drug that affects serotonin, a chemical in the brain.
- It’s believed that Trazodone might help in treating horses with acute laminitis (a painful foot condition) by reducing their movement or making them lie down more.
Objective
- Check how Trazodone, when given orally (PO), affects the movement and lying down behavior of healthy horses.
- Study the drug’s behavior in the body (pharmacokinetics) after giving multiple oral doses.
Methods
- Using a specific study design, 8 healthy horses were randomly given either a placebo or Trazodone in two different doses. This was done twice a day for 2 days. There was a 14-day break between treatments.
- They used a device on the horse’s hoof and video monitoring to count steps and see when the horses lay down.
- They used statistical methods to compare the groups.
- The levels of Trazodone and another related compound in the blood were measured using advanced techniques. They also studied how the drug behaved in the body.
Results
- Horses that received the higher dose of Trazodone (7.5 mg/kg) took fewer steps than those in the control group.
- When they compared the total number of steps over time, the high-dose group had significantly fewer steps than both the low-dose group and the control group.
- There was no change in the number or duration of times the horses lay down.
- The drug reached consistent levels in the blood, with a specific accumulation ratio.
Conclusions
- While Trazodone didn’t make the horses lie down more, it did reduce their steps by about 44% when given at the higher dose of 7.5 mg/kg twice a day.
Cite This Article
APA
Hobbs K, Luethy D, Davis J, Mallicote M, Torcivia C, Kulp J, Stefanovski D, Futterman C, Cooper F, van Eps A.
(2023).
The effects of orally administered trazodone on ambulation and recumbency in healthy horses.
J Vet Intern Med.
https://doi.org/10.1111/jvim.16821 Publication
Researcher Affiliations
- Department of Large Animal Clinical Sciences, University of Florida College of Veterinary Medicine, Gainesville, Florida, USA.
- Department of Large Animal Clinical Sciences, University of Florida College of Veterinary Medicine, Gainesville, Florida, USA.
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg, Virginia, USA.
- Department of Large Animal Clinical Sciences, University of Florida College of Veterinary Medicine, Gainesville, Florida, USA.
- Department of Clinical Studies-New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA.
- Department of Clinical Studies-New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA.
- Department of Clinical Studies-New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA.
- Department of Large Animal Clinical Sciences, University of Florida College of Veterinary Medicine, Gainesville, Florida, USA.
- Department of Large Animal Clinical Sciences, University of Florida College of Veterinary Medicine, Gainesville, Florida, USA.
- Department of Clinical Studies-New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA.
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Citations
This article has been cited 3 times.- Klinck M, Lovett A, Sykes B. Incorporating a Behavioral Medicine Approach in the Multi-Modal Management of Chronic Equine Gastric Ulcer Syndrome (EGUS): A Clinical Commentary. Animals (Basel) 2025 Oct 17;15(20).
- Joseph EJ, Love L, Mayakis M, Varner K. Preanesthetic Administration of Trazodone Does Not Impact Anesthetic Recovery Scores in Horses. Animals (Basel) 2025 Oct 6;15(19).
- Chow L, Kawahisa-Piquini G, Bass L, Hendrickson D, Patel A, Rockow M, Dow S, Pezzanite LM. Correlation of fecal microbiome dysregulation to synovial transcriptome in an equine model of obesity associated osteoarthritis. Ann Transl Med 2024 Dec 24;12(6):112.
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