Pharmacokinetics of gallium nitrate in man

Abstract

Gallium nitrate is a new antineoplastic agent that has shown activity in a number of in vitro tumor systems. During a Phase I clinical trial, the pharmacokinetics of two methods of administration of gallium nitrate were studied: a seven‐day continuous intravenous infusion, and a weekly rapid intravenous infusion. During the continuous infusion of 200 mg/M² of gallium nitrate, plasma gallium concentrations of 0.9 ± 0.2 μg/ml in one paitent, and 1.9 ± 0.4 μg/ml in a second were noted. Urine excretion of gallium approximated the daily administered dose by day 2–3. Overall, 68–107% of the total administered dose was recovered in the urine. Following a rapid intravenous infusion, a biphasic curve was generated. The T 1/2 α ranged from 8.3–26 minutes; the T 1/2 β from 6.3–196 hours. From 69–91% of the administered dose was recovered in the urine. The effects of gallium nitrate on tissue localization and body retention of ⁶⁷Ga are also presented.