Veterinary Drugs and Treatments
Darbepoetin may potentially be useful in treating anemia of chronic
kidney disease in dogs and cats. It may be less immunogenic than
epoetin, but this is only theoretical and has not been documented.
Another advantage is that doses may be administered less often to
maintain PCV. Treatment costs may be higher than using epoetin,
however.
Metabolism
The metabolic fate of both endogenous and recombinant
erythropoietin is poorly understood. Current evidence
from studies in animals suggests that hepatic metabolism
contributes only minimally to elimination of the intact
hormone, but desialylated epoetin (ie, terminal sialic
acid groups removed) appears to undergo substantial
hepatic clearance via metabolic pathways and/or binding.
Desialylation and/or removal of the oligosaccharide side
chains of erythropoietin appear to occur principally in the
liver; bone marrow also may have a role in catabolism of
the hormone.
Elimination of desialylated drug by the kidneys, bone
marrow, and spleen also may occur; results of animal
studies suggest that proximal renal tubular secretion may
be involved in renal elimination. In preclinical studies it
has been shown that renal clearance of darbepoetin is
minimal (up to 2% of total clearance).
