Pharmacokinetics of two amitriptyline tablets, Amitryptiline Nycomed and Amitryptiline, was investigated clinically and experimentally after a single oral dose of 50 mg. A statistically significant correlation between amitryptiline serum concentrations in dogs and healthy humans (r=0.683, p<0.006) was established. In humans, standartized values of peak concentration and area under the concentration curve were significantly higher, specific volume of distribution and total clearance were lower, and half-life and mean retention time were significantly higher than in dogs. Characteristics of apparent bioavailability in dogs and healthy people did not statistically differ.