Absorption and Excretion of Furosemide-S35 in Human Subjects

Abstract

17time from pool acetate to expired C02 as 60 minutes which is slightly shorter than the half life from the carboxyl carbon of acetate to C02 obtained in this investigation of 76.5 minutes. This result following equilibration during an infusion period is probably a better figure than that obtained following a single injection. The longer half life (135 min) of conversion from the methyl carbon of acetate to pool C02 found when 2-C14 acetate was infused, emphasizes the difference in the pathway of oxidation of the methyl carbon and of the carboxyl carbon of acetate.The biological half lives, as calculated from the fall of specific activity of body pool bicarbonate and from expired C02, are in excellent agreement. Thus, blood data may be used for studying the oxidative rates of acetate, eliminating the turnover time of the bicarbonate pool which otherwise masks the picture of oxidation in the animal body.Summary. The rates of oxidation of acetate to COa were estimated by using l-C14 and 2-C14 labeled acetate and measuring both blood and expired C1402. Following 1-C14 labeled acetate infusion, the half life of blood and expired C140a was about 76 minutes indicating a mean turnover time of acetate carboxyl to pool C02 of about 110 minutes.The half lives of 2-C14 labeled acetate were 135 minutes and 195 minutes respectively. The half life of the pool acetate was 1.2 minutes; turnover time 1.7 minutes; turnover rate 3.4 meq per hour and pool size 6.0 meq per sheep.

Kinetic disposition and diuretic effect of frusemide in acute pulmonary oedema.

“…The shortest T, aL in our study was twice as long as mean values reported for normal volunteers or patients with uremia (Andreasen & Mikkelson, 1977; Calesnick, Christensen & Richter, 1966;Rane, Villeneuve, Stone, Neis, Wilkinson & Branch, 1978).…”

Renal action, therapeutic use, and pharmacokinetics of the diuretic bumetanide

“…1 , 19 This greater potency is not explained by differences in drug absorption as roughly the same proportions of equipotent oral doses of both drugs are excreted in the urine. 3 Bumetanide is rapidly absorbed from the gut as shown by the early peaks in serum concentration after oral administration and the similar magnitude of total natriuretic response after oral and intravenous administration of the drug.…”

Pharmacokinetics and metabolism of furosemide in man

“…Healthy persons. -Calesnick et al (7) found that in two healthy volunteers given 35S-furosemide at the dosage of 50 mg the maximum plasma radioactivity levels were observed after 60 minutes. Kelly et al (16) observed no differences in drug absorption whether administered in the form of tablets or solution.…”

“…Most pharmacokinetic data have been obtained using preparations labelled with radioactive sulfur (7,16,32,33) and carbon (20,22,26,27,28). The drug's concentration in biologic fluids can also be measured using Bratton and Marshall diazotization method.…”