Safe usage of this preparation in pregnancy has not been established. Therefore, use of it during pregnancy should be avoided except when in the judgment of the physician the benefit outweighs the possible hazard. It is also advisable to make routine blood examinations, particularly blood cell counts and hemoglobin determinations, during therapy. Discontinue drug immediately if marked darkening of urine, or sudden decrease in hemoglobin concentration or leukocyte count occurs. The most striking symptoms are granulocytopenia and acute hemolytic anemia in sensitive persons.
Acute hemolysis occurs, but patients recover completely if the dosage is discontinued.
Empty the stomach by emesis or aspiration and lavage. Assist respiration and administer i.v. fluids and vasopressors for hypotension. Ammonium chloride in doses up to 12 g daily orally may be given to enhance urinary excretion. Electrical pacing of the heart may be needed. Patients suffering from an attack of vivax or ovale malaria or having parasitized red blood cells should receive a course of chloroquine phosphate, which quickly destroys the erythrocytic parasites and terminates the paroxysm.