Page 1257 - Small Animal Internal Medicine, 6th Edition

CHAPTER 72 Treatment of Primary Immune-Mediated Diseases 1229

The pharmacokinetics of pentoxifylline have been described Beale KM, et al. Systemic toxicosis associated with azathioprine
administration in domestic cats. Am J Vet Res. 1992;53:1236.
in the dog, and the current dose recommendation is 10 to Behrend E, et al. Pharmacology, indications, and complications. Vet
VetBooks.ir 15 mg/kg PO q8h. In veterinary medicine, pentoxifylline Bianco D, et al. A prospective randomized double blinded, placebo
Clin North Am Small Anim Pract. 1997;27:187.
has primarily been used for the management of cutane-
ous immune-mediated diseases, including dermatomyosi-
tis, SLE, and various forms of vasculitis. Whether the drug controlled study of human intravenous immunoglobulin for the
acute management of presumptive primary immune mediated
might be beneficial in other immune-mediated diseases is thrombocytopenia in dogs. J Vet Intern Med. 2009;23:1071.
not known. Adverse effects in dogs are uncommon but may Boothe DM. Small animal clinical pharmacology and therapeutics.
include vomiting, diarrhea, bone marrow suppression, and 2nd ed. Philadelphia: Elsevier; 2012.
flushing. Colopy SA, et al. Efficacy of leflunomide for treatment of immune-
mediated polyarthritis in dogs: 14 cases (2006-2008). J Am Vet
Med Assoc. 2010;236:312.
VINCRISTINE Dewey CW, et al. Mycophenolate mofetil treatment in dogs with
serologically diagnosed acquired myasthenia gravis: 27 cases
Vincristine is an alkaloid derived from the periwinkle plant. (1999-2008). J Am Vet Med Assoc. 2010;236:664.
It is used as an antineoplastic and immunosuppressive agent. Flint SK, et al. Independent and combined effects of prednisone
and acetylsalicylic acid on thromboelastography variables in
Vincristine binds to the microtubular structural protein healthy dogs. Am J Vet Res. 2011;72:1325.
tubulin, which is abundant within platelets. At low doses the Grau-Bassas ER, et al. Vincristine impairs platelet aggregation in
drug causes a transient increase in circulating platelet dogs with lymphoma. J Vet Intern Med. 2000;14:81.
numbers; at higher doses it can cause myelosuppression and Griffiths LG, et al. Cyclosporine as the sole treatment for anal
thrombocytopenia. Proposed mechanisms for increased furunculosis: preliminary results. J Small Anim Pract. 1999;40:569.
platelet numbers in normal dogs include stimulation of Guaguere E, et al. A new drug in the field of canine dermatology.
thrombopoiesis by circulating thrombopoietic factors Vet Dermatology. 2004;15:61.
(perhaps by concealing platelets from the thrombopoietic Hardie RJ, et al. Cyclosporine treatment of anal furunculosis in 26
regulatory system) or by inducing acute fragmentation of dogs. J Small Anim Pract. 2005;46:3.
mature megakaryocytes. In ITP, in which stimulation of Heinrich NA, et al. Adverse events in 50 cats with allergic derma-
titis receiving cyclosporin. Vet Dermatol. 2011;22:511.
thrombopoiesis is already maximal, the mechanisms for Horgan JE, et al. Splenectomy as an adjunctive treatment for dogs
increased platelet numbers are most likely increased platelet with immune-mediated hemolytic anemia: ten cases (2003-2006).
release from the bone marrow and impaired platelet destruc- J Vet Emerg Crit Care. 2009;19:254.
tion from inhibition of phagocytosis, or interference with Katayama M, et al. Effects of multiple oral dosing of itraconazole
antibody binding to platelets. Decreased antibody synthesis on the pharmacokinetics of cyclosporine in cats. J Fel Med Surg.
seems less likely considering the short time course for the 2010;6:512.
increase in platelet count (median 3 days for platelet recov- Mathews KA, et al. Randomized controlled trial of cyclosporine for
ery). Disruption of structure and function of platelets has treatment of perianal fistulas in dogs. J Am Vet Med Assoc.
been reported after exposure to vincristine in vitro and in 1997;211:1249.
vivo in dogs with lymphoma; however, the clinical signifi- Miller E. The use of cytotoxic agents in the treatment of immune-
cance of this finding is unclear. mediated diseases of dogs and cats. Semin Vet Med Surg (Small
The major indication for vincristine in treatment of Anim). 1997;12:144.
immune-mediated disease is as adjunctive therapy for dogs Mouatt JG, et al. Cyclosporine and ketoconazole interaction for
treatment of perianal fistulas in the dog. Aust Vet J. 2002;80:207.
with severe ITP. Vincristine-treated dogs with ITP have a Ogilvie GK, et al. Short-term effect of cyclophosphamide and aza-
more rapid increase in platelet number and shorter duration thioprine on selected aspects of the canine blastogenic response.
of hospitalization than dogs treated with prednisone alone. Vet Immunol Immunopath. 1988;18:119.
Vincristine is administered at 0.02 mg/kg IV as a single dose Olivry T, et al. Randomized controlled trial of the efficacy of
in conjunction with glucocorticoids. The advantages of vin- cyclosporine in the treatment of atopic dermatitis in dogs. J Am
cristine are that it is readily available and inexpensive. Vet Med Assoc. 2002;221:370.
Although bone marrow suppression may occur at higher O’Neill T, et al. Efficacy of combined cyclosporine A and ketocon-
doses, this has not been reported at the low single dose used azole treatment of anal furunculosis. J Small Anim Pract.
for treatment of ITP. Care should be taken during intrave- 2004;45:238.
nous administration because the drug is highly caustic if Patricelli AJ, et al. Cyclosporine and ketoconazole for the treatment
of perianal fistulas in dogs. J Am Vet Med Assoc. 2002;220:1009.
extravasation occurs.
Rinkardt NE, et al. Azathioprine induced bone marrow toxicity in
four dogs. Can Vet J. 1996;37:612.
Suggested Readings
Roberts ES, et al. Safety, tolerability, and pharmacokinetic of
Allenspach K, et al. Pharmacokinetics and clinical efficacy of 6-month daily dosing of an oral formulation of cyclosporine
cyclosporine treatment of dogs with steroid refractory inflamma- (ATOPIC for cats) in cats. J Vet Pharmac Therap. 2014;37:161.
tory bowel disease. J Vet Intern Med. 2006;20:239. Rodriguez DB, et al. Relationship between red blood cell thiopurine
Beale KM. Azathioprine for treatment of immune-mediated dis- methyltransferase activity and myelotoxicity in dogs receiving
eases of dogs and cats. J Am Vet Med Assoc. 1988;192:1316. azathioprine. J Vet Intern Med. 2004;18:339.