Postoperative analgesia and side effects of oral or injectable metamizole (dipyrone) in dogs and cats



Open Access Logo



PICO Question

In dogs and cats after surgery, does the peri-operative administration of injectable or oral metamizole (dipyrone) as opposed to no intervention result in lower postoperative pain scores or higher incidence of side effects?


Clinical bottom line

Category of research


Number and type of study designs reviewed

Three prospective, randomised, blinded, clinical studies were critically reviewed.

Strength of evidence


Outcomes reported

Variables assessed included: different pain assessment methods, metamizole dose required to reduce peri- and postoperative pain scores, changes in cardiovascular variables (heart rate, systolic, mean and diastolic blood pressure), changes in respiratory variables and variations in haematological and biochemical variables.


In healthy cats and dogs undergoing ovariohysterectomy, the use of metamizole in the peri- and postoperative period was associated with some reduction in pain levels (i.e., lower pain score or reduced need for rescue analgesia). In dogs, metamizole alone provided insufficient analgesia. No study evaluating metamizole after orthopaedic surgery was found. No evidence suggested that using metamizole peri-operatively resulted in higher incidence of side effects.


How to apply this evidence in practice

The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources.

Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.


Campos, C., de Gregorio, R., García-Nieto, R., Gabo, F., Ortiz, P. & Alemany, S. (1999). Regulation of cyclooxygenase activity by metamizol. European Journal of Pharmacology. 378(3), 339–347. DOI:

Giorgi, M., Łebkowska-Wieruszewska, B., Lisowski, A., Owen, H., Poapolathep, A., Kim, T.W. & De Vito, V. (2018). Pharmacokinetic profiles of the active metamizole metabolites after four different routes of administration in healthy dogs. Journal of Veterinary Pharmacology and Therapeutics. 41(3), 428–436. DOI:

Goncalves dos Santos, G., Vieira Dias, E., Teixeira, J.M., Pedro Athie, M.C., Magayewski Bonet, I.J., Herrera Tambeli, C. & Amilcar Parada, C. (2014). The analgesic effect of dipyrone in peripheral tissue involves two different mechanisms: Neuronal KATP channel opening and CB1 receptor activation. European Journal of Pharmacology. 741, 124–131. DOI:

Gorczak, R., Avila Valandro, M., Welter Pereira, B., Segatto, T., Vilibaldo Beckmann, D. & Thiesen, R. (2022). Continuous infusion of dipyrone in bitches in the intraoperative period: cardiorespiratory effects. Semina Ciências Agrárias. 43(2), 827–840. DOI: https ://

Imagawa, V.H., Fantoni, D.T., Tatarunas, A.C., Mastrocinque, S., Almeida, T.F., Ferreira, F. & Posso, I.P. (2011). The use of different doses of metamizol for post-operative analgesia in dogs. Veterinary Anaesthesia and Analgesia. 38(4), 385–393. DOI:

Kötter, T., da Costa, B.R., Fässler, M., Blozik, E., Linde, K., Jüni, P., Reichenbach, S. & Scherer, M. (2015). Metamizole-Associated Adverse Events: A Systematic Review and Meta-Analysis. PLoS ONE. 10(4), e0122918. DOI:

Lebkowska-Wieruszewska, B., Kim, T.W., Chea, B., Owen, H., Poapolathep, A. & Giorgi, M. (2018). Pharmacokinetic profiles of the two major active metabolites of metamizole (dipyrone) in cats following three different routes of administration. Journal of Veterinary Pharmacology and Therapeutics. 41(2), 334–339. DOI:

Neugebauer, V., Schaible, H.G., He, X., Lücke, T., Gündling, P. & Schmidt, R.F. (1994). Electrophysiological evidence for a spinal antinociceptive action of dipyrone. Agents Actions. 41(1–2), 62–70. DOI:

Shah, R.R. (2019). Metamizole (dipyrone)-induced agranulocytosis: Does the risk vary according to ethnicity? Journal of Clinical Pharmacy and Therapeutics. 44(1), 129–133. DOI:

Silva, I.C., Maia, C.A.A., Raymundo, A.C., Prata, M.N.L., Romero, T.R.L., Duarte, I.D.G., Manrique, W.G., Pérez, A.C. & Belo, M.A.A. (2021). META-ANALYSIS OF THE THERAPEUTIC USE OF DIPYRONE IN DOGS: PHARMACOLOGICAL EFFECTS AND CLINICAL SAFETY. Ars Veterinaria. 37(1), 21–30. DOI:

Teixeira, L.G., Martins, L.R., Schimites, P.I., Dornelles, G.L., Aiello, G., Oliveira, J.S., da Silva, F.C., Brum, B.T., Mc Walter, T., Andrade, C.M. & Soares, A.V. (2020). Evaluation of postoperative pain and toxicological aspects of the use of dipyrone and tramadol in cats. Journal of Feline Medicine and Surgery. 22(6), 467–475. DOI:

Tortorici, V., Vasquez, E. & Vanegas, H. (1996). Naloxone partial reversal of the antinociception produced by dipyrone microinjected into the periaqueductal gray of rats. Possible involvement of medullary off- and on-cells. Brain Research. 725(1), 106–110. DOI:

Veras de Paula, V., Araújo-Silva, G., Fernandes, N.S., Mouta, A.N., Nunes, T.L., Lopes Correia de Paiva, A., Barbalho de Macêdo, L., Nóbrega Arcoverde, K.& Pérez Urizar, J.T. (2023). Pharmacokinetic profiles of the two major active metabolites of metamizole, 4-methylaminoantipyrine (MAA) and 4-aminoantipyrine (AA), after intravenous injection in cats. Research in Veterinary Science. 155, 156–160. DOI:

Zanuzzo, F.S., Teixeira-Neto, F.J., Teixeira, L.R., Diniz, M.S., Souza, V.L., Thomazini, C.M. & Steagall, P.V. (2015). Analgesic and antihyperalgesic effects of dipyrone, meloxicam or a dipyrone-meloxicam combination in bitches undergoing ovariohysterectomy. The Veterinary Journal. 205(1), 33–37. DOI:

Vol. 8 No. 4 (2023): The fourth issue of 2023

Section: Knowledge Summaries

Categories :  Small Animal  /  Dogs  /  Cats  /  Rabbits  /  Production Animal  /  Cattle  /  Sheep  /  Pig  /  Equine  /  Exotics  /