A comparison of the various routes of administration of erythromycin in cattle

Abstract

A comparison of i.v., i.m. and s.c. administration erythromycin base in polyethylene glycol at 15 mg/kg and 30 mg/kg body weight was carried out in beef-type calves of approximately 200 kg body weight. Additional evaluations were carried out with oral administration of erythromycin phosphate and erythromycin stearate. Absorption of erythromycin was very slow by both the i.m. and s.c. routes of administration with a Kab of 0.0135 min-1 and 0.0185 min-1 for i.m. and 0.0032 min-1 and 0.0074 min-1 for s.c. at 15 mg/kg and 30 mg/kg, respectively. The bioavailability (32-42%) and peak serum concentrations were much lower with s.c. than with i.m. (60-65%) administration. The disposition of erythromycin administered i.v. appeared to be representative of dose-dependent kinetics rather than dose-independent first-order kinetics inasmuch as the elimination half-time (t1/2B) increased from 174.5 +/- 13 min for the 15 mg/kg dosage to 239 +/- 10.8 min with 30 mg/kg dosage. An acute apparent cardiovascular effect accompanied i.v. administration of erythromycin at 30 mg/kg dosage but not at 15 mg/kg. Severe diarrhea followed oral administration of either erythromycin phosphate or erythromycin stearate.

Assessment of the effects of erythromycin, neostigmine, and metoclopramide on abomasal motility and emptying rate in calves

“…44 Erythromycin should not be administered orally to ruminant cattle because it appears to be degraded by ruminal microflora, 44 and at a dosage of 30 mg/kg, PO, every 24 hours, it induces severe diarrhea and death in beef calves weighing 200 to 250 kg. 37 Because the calves in our study were clinically healthy and did not have any apparent signs of abnormal abomasal motility, we cannot directly comment on the prokinetic effect of erythromycin after parenteral administration in calves or adult cattle with abomasal disorders, such as left displacement of the abomasum or abomasal impaction, or after surgical correction of abomasal volvulus. However, erythromycin is highly effective in facilitating gastric motility and increasing gastric emptying rate in humans and dogs with gastric paresis, 32,40,45 and the treatment of gastric hypomotility is considered the most promising area of application.…”

“…Treatments were administered 30 minutes before feeding because prokinetic agents are usually administered to humans 15 to 30 minutes before meals. 36 The dosage protocol for erythromycin was based on the manufacturer's recommended antimicrobial dose (4 mg/lb, which is equivalent to 8.8 mg/kg) and the results of a pharmacokinetic study 37 that indicated erythromycin base (15 mg/kg) was rapidly absorbed after IM injection, with maximal serum concentrations being achieved within 3 hours. The dose was similar to that administered to 2 adult cattle (10 mg/kg, IM) in another study.…”

Pharmacokinetics of azithromycin after i.v. and i.m. administration to sheep

“…administration of macrolides is not a recommended route. In veterinary medicine macrolides are normally administered by deep i.m injection (Burrows et al. , 1989; Benchaoui et al.…”

Orally Administered Erythromycin in Rainbow Trout ( Oncorhynchus mykiss ): Residues in Edible Tissues and Withdrawal Time

“…Pharmacokinetic studies with erythromycin in cow, guinea pig, horse, rat, foal, pigeon, and human have been carried out (6,12,16,20,22,36,37). With regard to aquatic species treated with erythromycin orally, Moffit et al (26) followed the accumulation and depletion of erythromycin thiocyanate in Chinook salmon (Oncorhynchus tshawytscha) and found that the drug was not detectable in the fish muscle 10 days after the last erythromycin feeding (using the same dosage as in our study, i.e., 100 mg kg Ϫ1 trout body weight day Ϫ1 for 21 days).…”