Efficacy of leflunomide for treatment of immune-mediated polyarthritis in dogs: 14 cases (2006–2008)

Abstract

Objective To evaluate efficacy and adverse effects of leflunomide for the treatment of naturally occurring immune-mediated polyarthritis (IMPA) in dogs. Design Retrospective case series. Animals 14 dogs with cytologically confirmed IMPA. Procedures Medical records were used to identify dogs with a diagnosis of IMPA that were treated with leflunomide. Signalment, radiographic findings, laboratory data, dosage of leflunomide, treatment duration, treatment response, and occurrence of adverse effects were determined from medical records. Results Mean ± SD initial dosage of leflunomide was 3.0 ± 0.5 mg/kg (1.4 ± 0.2 mg/lb) PO once daily. Treatment duration for the initial starting dosage ranged from 1 to 6 weeks. Of the 14 dogs treated with leflunomide, 8 had complete resolution of clinical signs of IMPA initially, 5 had partial response to treatment, and 1 had minimal response to treatment. Adverse effects from treatment with leflunomide were not observed during the treatment period. Conclusions and Clinical Relevance Oral administration of leflunomide was a safe and effective alternative to oral administration of corticosteroids for treatment of IMPA in dogs. On the basis of findings in this study, a starting dosage for leflunomide of 3 to 4 mg/kg (1.4 to 1.8 mg/lb) PO once daily for at least 6 weeks before making dose adjustments is recommended. Dose adjustments should be based on cytologic evaluation of synovial fluid and clinical signs of IMPA. Hematologic variables, serum biochemical analysis results, and clinical signs of IMPA should be monitored for evidence of adverse effects to treatment with leflunomide.

Clinical features and pathological joint changes in dogs with erosive immune-mediated polyarthritis: 13 cases (2004–2012)

“…If lymphocyte signaling is a key factor in the development of erosive IMPA, immunomodulatory drugs that target lymphocyte function such as leflunomide, which specifically inhibits T cell proliferation and B cell antibody production, might be particularly useful for treatment of dogs with erosive disease. 1,16 Further research that involves the identification of lymphocyte subsets within the synovial fluid of dogs with erosive IMPA is warranted to elucidate the role of synovial lymphocytes in the pathogenesis of the disease. For example, type 17 helper T lymphocytes produce interleukin-17 and have a role in the development of neutrophilic inflammation as well as osteoclast activation, which results in bone loss in human patients with rheumatoid arthritis.…”

“…1,2 Clinical signs are associated with pathological changes in the affected joints and frequently include signs of pain or stiffness, joint effusion, and lameness. 3,4 Affected dogs may also be febrile with anorexia and lethargy.…”

Poliartrite em cães - 27 casos (2007-2013)

“…(JOHNSON & MACKIN, 2012b). Falha no tratamento pode resultar em persistência ou recorrência desses sinais (COLOPY et al, 2010). Outros fármacos como quimioterápicos e imunomoduladores são alternativas eficazes para o tratamento de cães com poliartrite (CLEMENTS et al, 2004;COLOPY et al, 2010;JOHNSON & MACKIN, 2012b).…”

“…Falha no tratamento pode resultar em persistência ou recorrência desses sinais (COLOPY et al, 2010). Outros fármacos como quimioterápicos e imunomoduladores são alternativas eficazes para o tratamento de cães com poliartrite (CLEMENTS et al, 2004;COLOPY et al, 2010;JOHNSON & MACKIN, 2012b). Segundo CLEMENTS et al (2004), 56% (n=39) dos cães tratados apresentaram remissão total dos sinais e 15% foram submetidos à eutanásia ou morreram pela progressão da doença, resultado semelhante ao encontrado nesta pesquisa, ou seja, (67% [12/18] e 28% [5/18], respectivamente).…”

“…Vários protocolos de tratamento têm sido propostos e pode envolver um único fármaco ou uma combinação de medicamentos, incluindo corticosteroides e agentes citotóxicos ou imunomoduladores. A melhor forma de avaliar a eficácia terapêutica é mediante a remissão dos sinais clínicos e principalmente pela avaliação citológica do líquido sinovial (COLOPY et al, 2010;JOHNSON & MACKIN, 2012b).…”