The theory of unintended consequences has gotten another boost. Although two drugs designed to slow the loss of kidney function in people with type 1 diabetes turned out to be busts, they had a wonderful but entirely unexpected side effect: Eye damage was reduced by 65 to 70 percent in the patients taking them.
Doctors have been using the two blood pressure drugs, enalapril and losartan, to slow the kidney damage caused by long-term type 1 diabetes. They are typically first prescribed about 15 years after diagnosis. But a five-year study that tracked 285 participants found virtually no difference in kidney function between those who took enalapril, those who took losartan, and those who were given a placebo. In other words, neither drug had the desired effect.
But while tracking kidney function, the researchers noticed that the drugs had a dramatic effect on the eye damage that almost always accompanies type 1. Compared to the placebo group, the group that took enalapril experienced 65 percent less eye damage, while those who took losartan experienced 70 percent less.
According to Dr. Michael Mauer, a professor of pediatrics and medicine at the University of Minnesota who led the study, the drugs could be a boon to type 1 patients who have begun to experience eye damage. The only drawback to either drug, each of which has a very good safety record, is the possibility of fetal damage if they are taken during pregnancy. He added that whether the drugs will prove effective against eye damage in people with type 2 diabetes is unknown and will require a separate study.