Liver microsomal benznidazole and nifurtimox nitroreductase activity in male rats of different age.

Nifurtimox (Nfx) and Benznidazole (Bz) are 2 drugs used in the chemotherapy of Chagas' disease, a sickness afflicting millions of Latin Americans. Their toxicity is related to nitroreductive activation. Nfx and Bz nitroreductase activity in liver microsomes from male rats is already present at low levels in the newborn and reaches full adult activity in 28 days. This suggests a better therapeutic approach by starting the treatment of transplacentally acquired Chagas' disease immediately after birth.