Chloroguanide is a biguanide
derivative and is usually used in combination with chloroquine or atovaquone,
for the prophy-laxis and treatment of acute, uncomplicated falciparum malaria,
particularly in areas where chloroquine resistance has been reported. It is a
prodrug that metabolises to cycloguanil, the active dihydrofolate reductase
inhibitor antimalarial agent, and is administered orally.
Adverse effects are uncommon and
manifest as occasional nausea and diarrhoea. Mouth ulceration, headaches,
dizzi-ness, and skin rash have also been reported. Total alopecia was reported
in several patients following chronic proguanil therapy. The severity of
alopecia was directly proportional to the duration of proguanil use and
appeared to be reversible upon discontinuation of the medication.
Overdose (more than 1 gm) may cause
vomiting, abdominal pain, diarrhoea and haematuria. Large doses of proguanil
may result in the transient appearance of epithelial cells and casts in the urine. Megaloblastic anaemia and
pancytopenia have been reported in patients with severe renal impairment.
Fatalities have not been reported.
Treatment is symptomatic and
supportive. Monitor CBC as indicated in symptomatic patients. Monitor fluid and
electrolyte status in patients with significant vomiting and/or diarrhoea.