Do cats receiving pre-appointment trazodone experience less stress during veterinary visits?

Question In cats does pre-appointment trazodone administration, compared to no trazodone, effectively reduce patients’ stress during veterinary visits?   Clinical bottom line The category of research question was: Treatment. The number and type of study designs that were critically appraised were: Two studies were identified and reviewed. One was a double blind, placebo controlled, randomised crossover study. The other was a blinded placebo controlled randomised crossover study. Critical appraisal of the selected papers meeting the inclusion criteria collectively provide zero/weak/moderate/strong evidence in terms of their experimental design and implementation: Weak. The outcomes reported are summarised as follows… In the first appraised paper 10 cats with ≥ 1 behavioural sign consistent with transport or veterinary examination associated anxiety were randomly assigned and orally administered a 50 mg trazodone tablet or a placebo (a sodium bicarbonate tablet identical in appearance to a trazodone tablet). 9/10 cats had anxiety-related signs during the veterinary visit when given the placebo, whereas 3/10 had them when given trazodone. Overall, behavioural scores assigned by the veterinarian were significantly (Wilcoxon signed rank test, P = 0.006) lower for cats after receiving trazodone versus the placebo. Trazodone administration resulted in significantly (Wilcoxon signed rank test, P = 0.01) more favourable tractability scores than with the placebo administration, with cats considered relaxed versus tense after receiving trazodone. For all components of the veterinary examination, trazodone administration resulted in significantly (McNemar test, P = 0.03 for each comparison) lower stress scores before, during and after veterinary examination. However, one cat was reported to become more fearful and vocal after trazodone administration. The second paper assessed the sedative and anxiolytic effects of 50 mg, 75 mg, and 100 mg trazodone administration to 6 purpose-bred, male, neutered laboratory cats, prior to and during a veterinary examination to a placebo (food or treats with no tablet). Since the 50 mg and 75 mg doses were not randomised the author of this Knowledge Summary did not include them as part of the statistical analysis. This study found no statistically significant difference in scoring between the effects of the 100 mg trazodone and the placebo, after analysis of the total behavioural and mean overall stress scores. There was a statistically significant difference in enclosure activity with lower levels of activity in cats administered 100 mg trazodone compared to the placebo. However, this is likely more reflective of the sedative effects of trazodone rather than anxiolysis. In view of the strength of evidence and the outcomes from the studies the following conclusion is made… The first appraised paper found promising evidence that trazodone could be effective at reducing stress in cats during veterinary visits. However, despite the strong study design, many limitations were identified, most notably the small sample size and large number of uncontrolled variables. This undermined the statistically significant data produced. The second study did not produce statistically significant evidence that trazodone ameliorates stress during a veterinary visit. A conclusion to the PICO question cannot be made due to lack of relevant studies and statistically significant data. Evidence found supporting the PICO question is weak and therefore more studies with larger sample sizes and less variability are needed to determine the efficacy of trazodone use to reduce stress in cats during veterinary visits.