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Randomized Controlled Trial
. 2017 Apr 12;12(4):e0175565.
doi: 10.1371/journal.pone.0175565. eCollection 2017.

Analgesic efficacy of tramadol in cats with naturally occurring osteoarthritis

Beatriz P Monteiro  1 , Mary P Klinck  1   2 , Maxim Moreau  1   2 , Martin Guillot  1   2 , Paulo V M Steagall  3 , Jean-Pierre Pelletier  2 , Johanne Martel-Pelletier  2 , Dominique Gauvin  1 , Jérôme R E Del Castillo  1 , Eric Troncy  1   2
Affiliations
Randomized Controlled Trial

Analgesic efficacy of tramadol in cats with naturally occurring osteoarthritis

Beatriz P Monteiro et al. PLoS One. .

Abstract

Objectives: This study aimed to (1) compare outcome assessments in normal and osteoarthritic cats and (2) evaluate the analgesic efficacy of tramadol in feline osteoarthritis (OA), in a prospective, randomised, blinded, placebo-controlled, crossover design.

Methods: Twenty cats were included after clinical examination, blood work and full body radiographs were performed. In Phase 1, outcome assessments aimed to differentiate normal (n = 5; i.e. exempt of any radiographic and clinical sign of OA) from OA (n = 15) cats. In Phase 2, OA cats were treated twice daily with a placebo (PG: cornstarch 15 mg) or tramadol (TG: 3 mg/kg) orally for 19 days, with a 3-month washout period between treatments. Evaluations were performed in normal and OA cats at baseline and consisted of: 1) peak vertical force (PVF) after staircase exercise; 2) telemetered night-time motor activity (NMA); and 3) response to mechanical temporal summation (RMTS). After treatment, PVF, NMA and RMTS evaluations were repeated in OA cats. Data were analysed with mixed model methods with an alpha-threshold of 5%.

Results: Phase 1: 1) PVF (% of body weight; mean ± SD) was higher in normal (59 ± 10.5) than in OA cats (50.6 ± 5.7) (p = 0.005); 2) NMA (no unit) was not different between groups; 3) RMTS (number of stimuli; median (range)) was higher in normal [29.5 (23.5-30)] than in OA cats [14 (8.5-28)] (p < 0.0001). Phase 2: PVF, NMA and RMTS presented a treatment effect (p = 0.024, p = 0.008 and p = 0.018, respectively). No clinically important adverse-effects were observed.

Conclusion: Outcome assessments such as kinetics (PVF) and evaluation of central sensitisation (RMTS) are discriminant of OA status. Mobility measured by NMA was not discriminant of OA status, however it increased in OA cats with tramadol treatment. Nociceptive hypersensitivity quantified by RMTS was evident in OA cats and was responsive to tramadol treatment.

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Conflict of interest statement

Competing Interests: The authors have the following interests. This study was partly supported by a Collaborative Research and Development grant (#RDCPJ 418399–2011, #RDCPJ 491953–2016, supporting operations and salaries) in partnership with ArthroLab Inc. from the Natural Sciences and Engineering Research Council of Canada. The Elanco sponsor was given the opportunity to review the manuscript and comment. There are no patents, products in development or marketed products to declare. This does not alter the authors’ adherence to all the PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors.

Figures

Fig 1
Fig 1. Individual values of peak vertical force before and after treatment in osteoarthritic cats.
A pressure-sensitive mat was used for collection of data. Each value is the average of three valid attempts of the most affected limb of each cat. Cats with OA were randomly divided into two groups to receive either placebo (n = 6) or tramadol (n = 7; 3 mg/kg every 12 hours orally) and were re-evaluated after 19 days of treatment. *Significant between- and within-group difference.
Fig 2
Fig 2. Night-time motor activity in cats with naturally occurring osteoarthritis.
A collar-attached accelerometer device was used for collection of data. Cats with OA (n = 14) were randomly divided into two groups in a crossover design to receive either placebo or tramadol (3 mg/kg) every 12 hours orally and were re-evaluated after 19 days of treatment. Values are presented as mean (SD). The dotted line represents the averaged night-time motor activity (no unit) observed in normal cats during baseline evaluations. *Significant between- and within-group difference.
Fig 3
Fig 3. Response to mechanical temporal summation (RMTS) in cats with naturally occurring osteoarthritis.
A mechanical device was used for collection of data. Cats with OA (n = 14) were randomly divided into two groups in a crossover design to receive either placebo or tramadol (3 mg/kg) every 12 hours orally and were re-evaluated after 19 days of treatment. Values are presented as mean (SD). The dotted line represents the number of mechanical stimuli (count) observed in normal cats during baseline evaluations. A significant between-group difference (MWW test) was found between normal cats and cats with osteoarthritis. *Significant between- and within-group difference.
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References

    1. Clarke SP, Bennett D. Feline osteoarthritis: a prospective study of 28 cases. J Small Anim Pract 2006; 47: 439–445. doi: 10.1111/j.1748-5827.2006.00143.x - DOI - PubMed
    1. Gunew MN, Menrath VH, Marshall RD. Long-term safety, efficacy and palatability of oral meloxicam at 0.01–0.03 mg/kg for treatment of osteoarthritic pain in cats. J Feline Med Surg 2008; 10: 235–241. doi: 10.1016/j.jfms.2007.10.007 - DOI - PMC - PubMed
    1. Guillot M, Moreau M, Heit M, Martel-Pelletier J, Pelletier JP, Troncy E. Characterization of osteoarthritis in cats and meloxicam efficacy using objective chronic pain evaluation tools. Vet J 2013; 196: 360–367. doi: 10.1016/j.tvjl.2013.01.009 - DOI - PubMed
    1. Guillot M, Taylor PM, Rialland P, Klinck MP, Martel-Pelletier J, Pelletier JP, et al. Evoked Temporal Summation in Cats to Highlight Central Sensitization Related to Osteoarthritis-Associated Chronic Pain: A Preliminary Study. PLoS One 2014; 9: e97347 doi: 10.1371/journal.pone.0097347 - DOI - PMC - PubMed
    1. Monteiro BP, Klinck MP, Moreau M, Guillot M, Steagall PV, Edge DK, et al. Analgesic efficacy of an oral transmucosal spray formulation of meloxicam alone or in combination with tramadol in cats with naturally occurring osteoarthritis. Vet Anaesth Analg 2016. February 24; - PubMed

Publication types

Grants and funding

This study was funded (Pr. Eric Troncy) in part by a Morris Animal Foundation Grant (#D09FE-803A), “TOP-CAT: Tracking Osteoarthritis Pain in the CAT”, by a Discovery grant (#441651–2013 supporting salaries) and a Collaborative Research and Development grant (#RDCPJ 418399–2011, #RDCPJ 491953–2016 supporting operations and salaries in partnership with ArthroLab Inc.) from the Natural Sciences and Engineering Research Council (NSERC) of Canada, as well as by an ongoing New Opportunities Fund grant (#9483) and a Leader Opportunity Fund grant (#24601), supporting pain/function equipment, from the Canada Foundation for Innovation. Funding for the clinical trial study was provided by a grant from Elanco Animal Health, a division of Eli Lilly and company. The funders had no role in study design, data collection, and analysis, decision to publish, or preparation of the manuscript. Dr. Beatriz Monteiro is the recipient of a Vanier Canada Graduate Scholarship. Dr. Mary Klinck was the recipient of an Alexander Graham Bell NSERC Canada Graduate Scholarship for Master’s research, of a Zoetis – Morris Animal Foundation (#D10-901) Doctoral Fellowship. Dr. Maxim Moreau received a Doctoral Scholarship from the Fonds de recherche du Québec-Santé, and a Doctoral Scholarship from the Canadian Institutes of Health Research – MENTOR Strategic Training Initiative in Health Research Program. Dr. Martin Guillot was the recipient of an Alexander Graham Bell NSERC Canada Graduate Scholarship for Doctorate research, and a Doctoral Scholarship from the Canadian Institutes of Health Research – MENTOR Strategic Training Initiative in Health Research Program.