title: Effect of parenteral administration of ivermectin and erythromycin on abomasal emptying rate in suckling calves.
abstract: OBJECTIVE-To evaluate the effect of parenteral administration of ivermectin and erythromycin on abomasal emptying rate in suckling calves. ANIMALS-6 male Holstein-Friesian calves < 15 days old. PROCEDURES-In a crossover study, calves were administered each of 3 treatments (control treatment, 2 mL of saline [0.9% NaCl] solution, IM; erythromycin, 8.8 mg/kg, IM; and ivermectin, 200 microg/kg, IV). Thirty minutes later, calves were bottle-fed 2 L of fresh cow's milk containing acetaminophen (50 mg/kg). Blood samples were collected from a jugular vein at various periods after suckling of milk. Abomasal emptying rate was assessed by use of the time to pharmacokinetically determined maximal plasma acetaminophen concentration. RESULTS-Administration of erythromycin and ivermectin caused a significant increase in abomasal emptying rate, compared with results for the control treatment, as determined on the basis of time to maximal plasma acetaminophen concentration. CONCLUSIONS AND CLINICAL RELEVANCE-Parenteral administration of erythromycin and ivermectin increased the abomasal emptying rate. The macrolide erythromycin can be an effective prokinetic agent in calves and other animals. Ivermectin is classified as a macrolide but has a number of structural differences from erythromycin. The clinical importance of a slight increase in abomasal emptying rate after IV administration of ivermectin remains to be determined because ivermectin is only labeled for SC, oral, and topical administration.
authors.affiliation: Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
authors.forename: Gholam-Reza
authors.initials: GR
authors.lastname: Afshari
authors.forename: Mohammad
authors.initials: M
authors.lastname: Nouri
authors.forename: Ebrahim Bani
authors.initials: EB
authors.lastname: Hassan
authors.forename: Mohammad-Reza
authors.initials: MR
authors.lastname: Mokhber-Dezfooli
authors.forename: Peter D
authors.initials: PD
authors.lastname: Constable