Treatment of Chagas' Disease
The treatment of Chagas' disease is indicated for patients with
the acute form of the disease or in congenital disease. No
information is available about the efficacy of drug treatment in
preventing the development of chronic disease. In these cases only
symptomatic treatment is adviced.
The following drugs are available:
- Nifurtimox (Lampit, a nitrofuran derivative) is active
against intracellular amastigotes as well as against the
trypomastigotes. It is given in daily doses of 10 mg per kg of
body weight to adults and 15 mg/kg to children for 60-90 days.
Since the drug causes oxidative stress its use should be avoided
in cases of glucose-6-phosphate dehydrogenase deficiency.
- Benznidazole (Radanil, a nitroimidazole derivative) is
active against intracellular amastigotes as well as against the
trypomastigotes. It is given in daily doses of 5-10 mg/kg for
30-60 days. Since the drug causes oxidative stress its use should
be avoided in cases of glucose-6-phosphate dehydrogenase
deficiency.
- Allopurinol, a experimental drug presently in use for
the treatment of gout.
- Gentian or crystal violet is used for blood transfusion
for the inactivation of trypanosomes in the blood.
Efficacy of the treatment
A problem associated with both nifurtimox and benznidazole is that
their therapeutic window
(difference between their ED50 and LD50) is rather small. Both drugs
are usually effective, but figures from Brazil indicate that
treatment may also fail.
Mode of action of the drugs
- Nifurtimox and Benznidazole are thought to
increase oxidant stress of the parasites leading to their killing
or inhibition of growth.
- Allopurinol is supposed to function as an alternative
substrate for the enzyme hypoxanthine guanine phosphoribosyl
transferase (HGPRTase), so allowing the incorporation of
allopurinol riboside into RNA, which leads to the inhibition of
protein synthesis in the parasite.
Prophylaxis
- It is adviced not to spend the night with the rural population
inside the primitive housing often infested with the triatomine
bug, the vector of Chagas disease.
- All blood for blood transfusion should be treated overnight
with Gentian violet (see above).
- Houses in rural areas where Chagas disease is endemic should
be treated with insecticides or with insecticide conatining
paints. Where possible proper housing with stone brick walls
should be provided to the population.
Read here about drug
development for Chagas' diesease and the Space shuttle
Back to the table of contents
Continue
Last updated: 22 October 1997.
created by :Fred
Opperdoes