The fate of praziquantel in the organism II. Distribution in rats

Summary

The qualitative and quantitative distribution profile of¹⁴C-praziquantel after single and repeated i. v. and oral administration was tested in Wistar rats.

After both modes of administration the¹⁴C-radioactivity tends to be localised mainly in the excretion organs liver and kidneys. Higher concentrations than in the plasma were also found in the lung, pancreas, adrenals, pituitary and Gl. mandibularis. Elimination of the drug and its metabolites from the organs is rapid. After 24 hours¹⁴C-praziquantel is eliminated almost completely.

Repeated daily administration of¹⁴C-praziquantel leads, in comparison to single administration, in many organs to slight increases in concentration; however, based on the low concentrations, organspecific accumulation can be excluded even after several administrations.

The investigations on the passage of¹⁴C-praziquantel through the placenta have shown that it is hardly taken up by the fetuses at all.

The autoradiograms as well as the quantitative data obtained after i. v. injection indicate that¹⁴C-praziquantel is secreted via the gastrointestinal mucosa.