Plasma level of diethylcarbamazine in jirds and hamsters

The relation between the dosage and plasma level of diethylcarbamazine (DEC) in jirds and hamsters was examined by gas-liquid chromatography. When the drug was given intraperitoneally to jirds at 100 mg/kg body weight, the plasma level rose rapidly and reached the maximum level (20-25 micrograms/ml) at 10 minutes and afterwards fell quickly to undetectable level at 4 hours. Even if larger dosage (300 mg/kg) was given, DEC was eliminated completely from the blood circulation within 8 hours. When the same dosages of DEC were given intraperitoneally, the DEC levels remained 2-4 hours longer in the blood of hamsters than in the blood of jirds. DEC given by stomach intubation at 100 mg/kg remained detectable much longer in hamsters (8 hrs) than in jirds (2 hrs). A repeated doses schedule did not show a tendency for the drug to accumulate. DEC was excreted in the urine and feces, but the total amount of drug excreted without metabolic changes was only about 8% of the given dosage. The majority of unmetabolized DEC was excreted in the urine within 0-12 hours.