Many elderly patients are being unnecessarily treated with diuretic drugs, according to research from the Netherlands.

Researchers looked at a group of 63 patients who were being given drug treatment for ankle edema (swollen ankles). Half the group were aged 65 to 74 and the rest older. Treatment with diuretics drugs which increase the loss of fluid from the body by promoting production of urine was withdrawn for 34 patients, chosen at random from the total sample, and a further 29 were kept on the drugs and monitored as the control group. The study found withdrawal successful in 26 of the 34.

Eight of the 34 patients in the withdrawal group needed to have diuretic treatment restarted and for four of this group "not resuming diuretics might have led to serious consequences". However, even here, withdrawal of treatment did not put them in any danger so long as they received proper monitoring. "In practice, patients who develop fluid retention with possible complications could be identified in time by making frequent follow up visits and giving clear instructions to patients about when to enlist medical help," say the researchers.

The study confirmed earlier findings that withdrawal of diuretic drugs leads to a rebound increase in fluid retention, but that this condition is temporary. "Six weeks after diuretic therapy was stopped, the edema, although still decreasing, had almost reached the starting level," they say.

They conclude that where underlying heart problems can be ruled out, and careful monitoring is provided, drug treatment can be safely withdrawn in elderly patients who have been prescribed diuretics for ankle edema.

!ABMJ, 19 February 1994.