Pharmacokinetics of dideoxyinosine in pigtailed macaques (Macaca nemestrina) after intravenous and subcutaneous administration.

Four macaques (Macaca nemestrina; 1 female and 3 males) were administered dideoxyinosine (DDI) at three dose levels (3.2 mg/kg i.v., 10 mg/kg i.v., and 20 mg/kg s.c.). Blood and urine samples were collected during 6-8 h and 24 h after drug administration, respectively. The mean plasma clearance (16.7 +/- 4.9 ml/min/kg), steady-state volume of distribution (1.5 +/- 0.4 L/kg), and terminal plasma half-life (96.8 +/- 7.5 min) did not differ significantly between the two i.v. doses. DDI was eliminated from the body primarily by excretion of the unchanged drug in the urine (74%). The absorption of DDI from the subcutaneous site was complete (bioavailability of 0.91 +/- 0.13) and rapid, with peak plasma concentration obtained at 30 min.