Proteinuria during long-term captopril therapy.

Proteinuria developed in six of 81 hypertensive patients given captopril for at least four months (protein excretion, greater than 200 mg/24 hr). Two had previously elevated protein excretion. In all patients the increased protein excretion occurred by the fourth month of treatment. It subsided in four after two to nine months, despite continued therapy. In two of the four, proteinuria cleared completely within seven months after onset, while in the other two it subsided to the range of 600 mg/24 hr. However, in the remaining two patients proteinuria persisted during captopril therapy and was associated with hypoalbuminemia and hypercholesterolemia. Renal biopsy specimens showed mild membranous nephropathy in two patients, one of whom had a remittance of proteinuria during continued captopril treatment.