Pharmacokinetics of trazodone after different routes of administration.

Pharmacokinetics study of trazodone after iv, ip and po administration has been performed in rats. Trazodone was given to animals in a single or multiple doses of 20 mg/kg p. o. or ip, or in doses of 5 and 10 mg/kg iv. The levels of the drug in plasma and brain tissue were assayed spectrofluorometrically at predetermined time intervals. The results indicate that neither the route of administration nor the dosage schedule affects in significant manner the pharmacokinetics of trazodone, but the pharmacokinetic parameters depend upon the dose used. The affinity of the drug to blood and brain tissue is nearly the same, in contrast to imipramine which shows, a low affinity to blood and high affinity to brain tissue.