Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Am J Vet Res. 2010 Oct;71(10):1201-6. doi: 10.2460/ajvr.71.10.1201.

Pharmacokinetics of metformin after enteral administration in insulin-resistant ponies.

Author information

  • 1School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW 2650, Australia.

Abstract

OBJECTIVE:

To determine pharmacokinetics and plasma steady-state kinetics of metformin after oral or nasogastric administration in insulin-resistant (IR) ponies.

ANIMALS:

8 IR ponies.

PROCEDURES:

Metformin (30 mg/kg) was administered to 8 ponies via nasogastric tube Blood samples were collected at intervals for 24 hours. Plasma concentrations of metformin were measured via liquid chromatography-electrospray tandem mass spectroscopy Pharmacokinetic variables were determined via noncompartmental analysis. Metformin (15 mg/kg, PO, twice daily [8 am and 5 pm]) was administered to 4 ponies for an additional 20 days, and blood samples were obtained every 2 days. Plasma concentration at steady state (Css) was determined.

RESULTS:

Mean±SD elimination half-life (t1/2) of metformin was 11.7±5.2 hours, maxima plasma concentration was 748±269 ng/mL at 54±32 minutes, mean area under the curve was 355±92 microg.h/mL, and apparent clearance was 90.6±28.1 mL/min/kg. The Css was 122±22 ng/mL.

CONCLUSIONS AND CLINICAL RELEVANCE:

Metformin reportedly enhances insulin sensitivity of peripheral tissues without stimulating insulin secretion, but bioavailability in horses is low. The t1/2 of metformin in IR ponies was similar to that in humans. Actual clearance of metformin adjusted for bioavailability in IR ponies was similar to that in humans; however, during chronic oral administration at dosages reported in efficacy studies, the Css of metformin was less than values associated with therapeutic efficacy in humans The apparent lack of long-term efficacy of metformin in horses is likely attributable to low bioavailability, rather than to rapid clearance.

PMID:
20919907
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Atypon
    Loading ...
    Write to the Help Desk