Overt hemolysis in patients with glucose-6-phosphate dehydrogenase deficiency: a survey in general practice.

The records of 129 patients with glucose-6-phosphate dehydrogenase deficiency from two general practices were reviewed for overt hemolysis. There were 25 such cases: 14 were diagnosed as favism; 10 were associated with various combinations of drugs, or with fever, infection, acidosis or the neonatal state; and one was of undetermined cause. Over the years 1952-72, these patients had been challenged on 756 occasions with potentially hemolytic drugs. The low incidence of overt hemolysis after antipyretic preparation is noted, as is the danger of nitrofurantoin. The clinical setting was an important determinant of whether hemolysis would occur after drug administration. Fever seemed to be a particularly significant factor. Quantitative determinations of enzyme activity in 18 patients confirmed the reliability of the screening method used. There was no correlation between the enzyme levels and the occurrence of overt hemolysis.