PT  - JOURNAL ARTICLE
AU  - Chay, S
AU  - Woods, W E
AU  - Rowse, K
AU  - Nugent, T E
AU  - Blake, J W
AU  - Tobin, T
TI  - The pharmacology of furosemide in the horse. V. Pharmacokinetics and blood levels of furosemide after intravenous administration.
DP  - 1983 May 01
TA  - Drug Metabolism and Disposition
PG  - 226--231
VI  - 11
IP  - 3
4099  - http://dmd.aspetjournals.org/content/11/3/226.short
4100  - http://dmd.aspetjournals.org/content/11/3/226.full
SO  - Drug Metab Dispos1983 May 01; 11
AB  - Studies were undertaken to determine blood levels of furosemide in horses after 0.5- and 1.0-mg/kg doses administered iv. Analyses indicated that the pharmacokinetic parameters were dose independent and best described by a three-compartment open model. The alpha-, beta-, and gamma-phase half-lives of 5.6, 22.3, and 158.5 min, respectively, were observed after the 0.5-mg/kg dose. Similarly, the respective half-lives after the 1.0-mg/kg dose were 5.8, 24.1, and 177.2 min. After a 0.5-mg/kg dose of furosemide, population frequency distributions were evaluated at 1 hr and 4 hr post-drug administration. At 1 hr after dosing, the blood levels of furosemide in 30 horses were normally distributed. The mean plasma level was 97.9 ng/ml with a range of 41.9 ng/ml to 155.8 ng/ml and a SD of 25.0 ng/ml. Analyses of blood levels of furosemide in 47 horses at 4 hr after drug administration indicated that the population distribution was better fit by a normal curve after log transformation of the values. The mean plasma level at 4 hr post-dosing was 9.6 ng/ml with a range of 4.0 ng/ml to 19.4 ng/ml and a SD of 3.1 ng/ml. Based on this population distribution of the plasma levels, the probability of finding furosemide plasma concentrations above 24.6 ng/ml at 4 hr after anti-epistaxis dose was estimated at less than 1 in 1000.