Abstract

In rats injected ip with 500 mg of cyclotrimethylenetrinitramine (RDX)/kg, the respective mean times to first seizure and to death were 23.8 and 171.0 min, and the mean plasma concentrations of RDX at seizure and death were 5.2 and 13.8 μg/ml. Following 100 mg/kg po, the plasma concentration was 2.1 μg/ml at 4 hr and 3.0 μg/ml at 24 hr, while the urine concentration was 5.5 μg/ml at 4 hr and 6.9 μg/ml at 24 hr. In the 6 days following 50 mg/kg po, 0.7% was excreted as RDX in the feces and 2.4% in the urine. Irrespective of dosage or route of administration, the concentration of RDX was greatest in kidney, most variable in liver, and did not accumulate in the brain. Twenty-four hours after po dosing with 50 mg of [ ¹⁴C]RDX/kg, the liver and urine contained large amounts of RDX metabolites, and, after the first 4 days, 90% of the total radioactivity was recovered: 34% in the urine, 43% as ¹⁴CO ₂, 3% in the feces, and 10% in the carcass. In miniature swine dosed with 100 mg/kg po, the plasma concentration was 1.6 μg/ml at 2 hr and 4.7 μg/ml at 24 hr, while the urinary concentration was 2.0 μg/ml at 2 hr and 3.6 μg/ml at 24 hr. At 24 hr, the concentrations of RDX in brain, heart, liver, kidney cortex, kidney medulla, and fat were between 4.4 and 9.1 μg/g. Convulsions in pigs occurred 12–24 hr after dosing with RDX.