Pharmacokinetic profile of sulphamonomethoxine-trimethoprim in horses after intravenous, intramuscular and oral administration.

Abstract

The pharmacokinetic profile of a sulphamonomethoxine-trimethoprim (SMM-TMP) combination was investigated in five horses. The combination was administered intravenously, intramuscularly and orally at a constant dose of 20 mg SMM plus 4 mg TMP kg-1 bodyweight. Following intravenous administration both drugs dispersed rapidly with distribution half-lives of about 12 minutes for SMM and about 18 minutes for TMP. Elimination half-lives for intravenous, intramuscular and oral administration were closely similar, indicating that elimination was independent of administration route. Bioavailability of the drugs in aqueous solution was good: about 72 per cent and 84 per cent for SMM and about 84 per cent and 98 per cent for TMP following intramuscular and oral administration, respectively. It is concluded that SMM-TMP administered orally once a day at 20 mg and 4 mg kg-1 bodyweight, respectively, maintains therapeutic concentrations, whereas twice daily intramuscular administration would be more effective for treating systemic infections in the horse than the once a day regimen usually adopted in veterinary practice.

• Authors: S Carli, O Sonzogni, R Villa, R Bignazzi, C Montesissa
• Journal: Research in veterinary science (Res Vet Sci) Vol. 54 Issue 2 Pg. 184-8 (Mar 1993) ISSN: 0034-5288 [Print] England
• PMID: 8460257 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Trimethoprim
• Sulfamonomethoxine

Topics

• Absorption
• Administration, Oral
• Animals
• Biological Availability
• Horses (metabolism)
• Injections, Intramuscular (veterinary)
• Injections, Intravenous (veterinary)
• Male
• Sulfamonomethoxine (administration & dosage, pharmacokinetics)
• Trimethoprim (administration & dosage, pharmacokinetics)