Interpreting blood pressure figures in cats who received oral pre-visit sedation
Pre-visit sedation with gabapentin, or less commonly gabapentin with trazodone for cats have become increasingly used in small animal practice. Pre-visit sedation can make consultations and some diagnostic procedures considerably less stressful for both the feline patient and the veterinary team.
Gabapentin is a structural analog of gamma-aminobutyric acid (GABA). It binds to the alpha-2-delta (α2δ) accessory subunit of the voltage-dependent calcium channel complexes, mainly in the spinal dorsal horn and the prosencephalon (forebrain). By doing this it reduces excitatory neurotransmission, producing anxiolytic effect and decreasing nociception. Although it is structurally related to gamma-aminobutyric acid (GABA), gabapentin does not appear to alter its binding, uptake or release.
Trazodone is an antidepressant drug that works as a serotonin antagonist and reuptake inhibitor (SARI) with dose-dependent effects on different brain receptors. In later years this drug has been extensively used for behaviour modification, anxiety reduction and in postoperative care mainly in dogs. However, recently trazodone has started to gain popularity for use in cats, especially in combination with gabapentin.
Gabapentin is the most commonly used drug for reducing fear and anxiety associated with transport and clinical visits. It is usually administered in doses of approximately 10–20 mg/kg PO some 2 to 3 hours before an anticipated stressful event.
Recent evidence suggests that gabapentin, apart from sedation effect, has a potential to produce a clinically relevant reduction in measured systemic blood pressure (BP) and this should be taken into account when interpreting blood pressure figures in cats who received gabapentin prior to veterinary visit. This means that pre-visit administration of gabapentin can move the patient between different risk categories when assessing hypertension.
A recent randomized, blinded, placebo-controlled crossover study (Quimby et al., 2024) showed that a single dose of gabapentin (10 mg/kg) given 3 hours before BP measurement can significantly lower systemic BP in cats who are apparently healthy, as well as in those with chronic kidney disease (IRIS stage 2-4). In this study the median change in systemic BP was reduction by 12 mmHg in both groups of cats. The two cats in this study were also receiving amlodipine for treatment of systemic hypertension. Although it has been suggested that these two drugs might be having synergistic effects on systemic BP, gabapentin -induced changes in BP in cats on amlodipine did not differ significantly from those obtained from cats who were not receiving amlodipine treatment.
However, in prospective, randomized and blinded study from Veronezi et al. (2022) that included 40 healthy cats aged between 6 months and 2 years, oral gabapentin in dose of 100 mg/cat that was given 90 minutes prior to procedure failed to produce statistically significant change in systemic BP figures.
When it comes to combination of gabapentin and trazodone, a study from Tucker et al. (2024) included 21 cats who received oral trazodone (5 mg/kg), oral gabapentin (10 mg/kg), the combination of both drugs and placebo. The sedation score was obtained 1 hour after administration and combination of drugs seemed to have caused more profound sedation without harmful side-effects.
A study from Siepmann et al. (2025) aimed to compare the sedative, hematological, biochemical and cardiovascular effects of oral single-dose trazodone and gabapentin, alone or in combination. In a prospective, randomized, cross-over, and placebo-controlled study 8 healthy adult mixed-breed domestic cats were assigned to receive an oral single dose of trazodone (50 mg), gabapentin (100 mg), trazodone (50 mg) in combination with gabapentin (100 mg), or placebo. Sedation score, physiological, hematological, biochemical, and cardiovascular variables were assessed at baseline and 120 minutes after drug administration. It was found that a combination of trazodone (50 mg/cat) and gabapentin (100 mg/cat) increased sedation scores when compared to gabapentin alone, and resulted in having a mild impact on heart rate, respiratory rate and systemic BP. The authors concluded that gabapentin in combination with trazodone enhances the sedation scores when compared to each drug alone, without significant cardiovascular, hematological, and biochemical effects.
The current ACVIM guidelines for the identification, evaluation and management of systemic hypertension in dogs and cats recommend that systemic BP should ideally be measured in non-sedated cats (Acierno et al., 2018). Gentle handling should be used to minimise stress, and cats should be allowed an acclimatisation period before BP measurement to reduce the effects of situational hypertension and improve the reliability of the measurement.
What does this mean in general practice?
When assessing blood pressure in a cat that has received pre-visit sedation, the oral drug, its dose and time of administration should be recorded and taken into consideration alongside the actual BP value and the patient's clinical context.
Although the evidence regarding the effect of pre-visit sedation on BP measurement is currently contradictory, a clinically relevant reduction in systemic BP may occur in some cats who received oral gabapentin and this is particularly important in borderline, unexpected or clinically discordant BP measurement results. In those cases it would be appropriate to repeat assessment under standardised and recommended conditions if possible.
References
Acierno, M.J., Brown, S., Coleman, A.E., Jepson, R.E., Papich, M., Stepien, R.L. and Syme, H.M. (2018) ‘ACVIM consensus statement: Guidelines for the identification, evaluation, and management of systemic hypertension in dogs and cats’, Journal of Veterinary Internal Medicine, 32(6), pp. 1803–1822. doi:10.1111/jvim.15331.
Quimby, J.M., Jones, S.E., Saffire, A., Brusach, K.K., Kurdziel, K., George, Z., Paschall, R.E. and Aarnes, T.K. (2024) ‘Assessment of the effect of gabapentin on blood pressure in cats with and without chronic kidney disease’, Journal of Feline Medicine and Surgery, 26(5), pp. 1–9. doi:10.1177/1098612X241240326
Siepmann, E.C., Dall’ Agnol Gianezini, E., Ruaro, M.E., Wolfran, L., Faria, C.A. and Fukushima, F.B. (2025) ‘Trazodone-gabapentin association increases sedation scores with mild hemodynamic and echocardiographic impact in healthy cats’, Topics in Companion Animal Medicine, 64, 100945. doi:10.1016/j.tcam.2024.100945.
Tucker, L.E., Sanchez, A., Valverde, A., Blois, S., Monteith, G., Longworth, P., Downie, A., Gu, Y. and Johnson, R. (2024) ‘Evaluation of the sedative properties of oral trazodone, gabapentin or their combination in healthy cats’, Journal of Feline Medicine and Surgery, 26(10), pp. 1–7. doi:10.1177/1098612X241281481.
Veronezi, T.M., Lopes, D.J., Zardo, I.L., Ferronatto, J.V.B., Trojan, M.M., Franck, K.R., de Azevedo, A.F., Spiering, A.G., Nunes, L.N., Fadel, L. and da Costa, F.V.A. (2022) ‘Evaluation of the effects of gabapentin on the physiologic and echocardiographic variables of healthy cats: a prospective, randomized and blinded study’, Journal of Feline Medicine and Surgery, 24(12), pp. e498–e504. doi:10.1177/1098612X221131270