Identification of anN-Oxide as the Major Metabolite of the AnalgesicO-(Diethylaminoethyl)-4-Chlorobenz-aldoxime Hydrochloride in Dogs

Publisher Website
Google Scholar
Abstract
1. After oral administration to dogs of the analgesic O-(diethylaminoethyl)-4-chloro[7-14C]benzaldoxime hydrochloride together with piperazine hydro-chloride (2:1, w/w), at a dose of 4.5 mg/kg, the radioactivity was well absorbed and rapidly excreted. During 5 days, 81% of the dose (ca. 50% in 12 h) was excreted in urine and 10% in faeces. 2. Rates and routes of excretion of radioactivity were not altered in animals pre-treated with the drug for fourteen days. 3. Peak mean plasma concentrations of radioactivity (5.5 μg equiv./ml) occurred at 90 min after an oral dose and were higher than those at 2 min following an equivalent intravenous (3.4 μg equiv. /ml) or rectal (4.0 μg equiv. /ml) dose which gave a max. at 45 min. 4. The drug was rapidly and extensively metabolized and no unchanged drug was detected in the plasma or urine. The major urinary metabolite was the N-oxide of the parent compound accounting for 34% and 23% dose excreted in the urine of males and females respectively during 12 h after administration.