D-penicillamine and prussian blue as antidotes against thallium intoxication in rats

D-penicillamine (DP) and prussian blue (PB), given alone and in combination, were evaluated in rats as treatments against acute thallotoxicosis. Animals were poisoned by intraperitoneal (i.p.) injection of thallium(I) acetate at different doses (16, 30, 40, 50 and 70 mg/kg). Later (24 h), treatments were administered until day 5, as follows: D-penicillamine (DP), 25 mg/kg, i.p. route, twice daily; prussian blue (PB), 50 mg/kg, oral route, twice daily. LD50 values were estimated for each treatment with the following results: control, 32 mg/kg; DP, 27 mg/kg; PB, 42 mg/kg; PB + DP, 64 mg/kg. Thallium content was analyzed in six body organs and eight brain regions after treatments. PB administration induced significant elimination of thallium from all tissues. DP treatment diminished thallium content in body organs, but increased it in brain regions, indicating a redistributive effect of DP. DP + PB treatment decreased thallium content in all body organs and brain regions. Renal thallium content in the DP + PB group was significantly lower than that of PB alone group, suggesting accelerated urinary excretion of thallium as a result of DP action. Results indicate that DP administered alone may be dangerous because of its redistributive effect, but given in combination with PB may be useful as treatment against thallium poisoning.