Avermectin

Avermectin is a family of anti-parasitic drugs whose analogues include ivermectin, selamectin, doramectin and abamectin.

Avermectin therapy for rodent fur mite infestation

A commonly used therapy in recent times has been based on oral or parenteral administration of avermectins, which are macrocyclic lactones produced by fermentation of the soil micro-organism Streptomyces avermitilis. They show activity against a broad range of nematodes and arthropod parasites of domestic animals at dose rates of 300 microgram/kg or less. Unlike the macrolide or polyene antibiotics, they lack significant antibacterial or antifungal activity (Hotson, 1982).

Avermectin therapy is not without its drawbacks. Resistance to avermectins has been reported, which suggests use in moderation (Clark, 1995). Research on ivermectin, piperazine, and dichlorvos in combinations also shows potential for toxicity (Toth, 2000). Avermectin has been reported to block LPS-induced secretion of tumor necrosis factor, nitric oxide, prostaglandin E2, and increase of intracellular concentration of Ca2+ (Victorov, 2003). A proven ectoparasite mitigation method that stresses lab animals less than avermectin oral administration is definitely desirable. Permethrin based treatments such as MiteArrest may be a viable alternative.

References

• Hotson IK, 1982, The avermectins: A new family of antiparasitic agents, J S Afr Vet Assoc., Jun;53(2):87-90.
• Clark JM, 1995, with Scott JG, Campos F, Bloomquist JR, Resistance to avermectins: extent, mechanisms, and management implications, Annu Rev Entomol, 40:1-30.
• Toth LA, 2000, with Oberbeck C, Straign CM, Frazier S, Rehg JE, Toxicity evaluation of prophylactic treatments for mites and pinworms in mice, Contemp Top Lab Anim Sci., Mar;39(2):18-21.
• Viktorov AV, 2003, with Yurkiv VA, Effect of ivermectin on function of liver macrophages, Bull Exp Biol Med., Dec;136(6):569-71.