Efectividad de la ivermectina como coadyuvante de la vincristina para el tratamiento de tumor venéreo transmisible en una población de 8 caninos.

Abstract

The canine transmissible venereal tumor (TVTC) is a benign neoplasia with a low rate of metastasis, it has a high presentation in the daily clinic; Its transmission is through the transfer of intact exfoliated cells. This tumor implantation requires a previously injured recipient genital mucosa, as occurs in intercourse, and it can be transmitted by behaviors such as licking or inhaling, giving a presentation at an extra genital level such as the skin, nasal cavity , eyes or mouth. TVT treatment aims at complete remission of the lesion, as well as preventing the development of metastatic lesions and recurrences. Chemotherapy is the treatment of choice for TVT, regardless of the extension, the size of the neoplasia, the occurrence of metastases or the duration of the disease, they are frequently used due to their low cost. The use of chemotherapy produces a good response for single and multiple tumors. Vincristine is the drug of first choice, since it has a high rate of efficacy as a single drug, although it can be used in combination. According to the study carried out by the Da Bahia Federal University of Veterinary Medicine and Zootechnics in Brazil, it was demonstrated that through cytological and histopathological findings, the association of ivermectin with vincristine, with a chemotherapy application protocol at a dose of 0.5 mg / m² once a week, followed by the application of ivermectin at a dose of 0.5mg/kg subcutaneously at the same time, causes a more rapid regression of the tumor (Lapa, 2009). Based on the study carried out, this is important since the frequency of chemotherapies in the patient and its adverse effects on them will be reduced. The interaction of ivermectin with Pglycoprotein is due to the affinity of ivermectin with this protein disputing the activation of the 14 ATPase enzyme (Lespine, 2006). Ivermectin interacts with P-glycoprotein decreasing resistance to chemotherapy (Lespine, 2006). The inhibitory action of P-glycoprotein can occur in two ways; Competition with drug binding sites, which are competitive inhibitors or blocking the ATP hydrolysis process (Huber, 2010), considered non-competitive inhibitors. In this way, ivermectin acts as a substrate, inhibiting the action of this glycoprotein (Bezerra, 2011).