Tolvaptan effective option in CKD with heart failure
medwireNews: Tolvaptan is an effective add-on diuretic for patients with chronic kidney disease (CKD) complicated by congestive heart failure, report researchers.
The drug produced a consistent diuretic effect in a study of individuals with CKD stage 4 or higher and congestive heart failure who were resistant to existing diuretics, say Yukinao Sakai (Nippon Medical School Musashikosugi Hospital, Kawasaki, Japan) and team.
"If the kidney has some residual function, tolvaptan, which is a water diuretic that significantly decreases urine osmolality, enables maintenance of the osmoregulation of the body fluids by the renal cortical collecting tubes," explains the team.
The study examined the additive effect of tolvapatan over 6 days in eight inpatients, aged a mean of 54 years, who were already using azosemide (n=2), eplerenone (n=1), torasemide (n=2), or furosemide (n=6) but had been nonresponsive to the therapies.
Tolvaptan was initially administered at 7.5 mg and, for five patients, increased to 15 mg/day after 2 or 3 days based on efficacy and adverse events.
The patients' mean serum creatinine level was 7.57 mg/dL before they began tolvaptan and five patients had cardiac function grade II, as defined by New York Heart Association criteria, while three had grade III function.
As reported in Clinical and Experimental Nephrology, there was a significant linear increase in the patients' mean urine volume with the administration of tolvaptan. And this increase was accompanied by a significant decrease in patients' urine osmolality.
In addition, the mean free water clearance showed a tendency to increase, although the change did not reach significance.
There were no cases of hypernatremia and no significant changes in sodium levels observed across the study period. There were also no significant changes in serum osmolality.
Furthermore, there was no increase in the mean serum creatinine level and no adverse effect on renal function, and when only patients with CKD stage 5 were analyzed, a significant decrease in serum creatinine level was in fact observed.
"We confirmed that tolvapatan has a diuretic effect in patients with both severe CKD and congestive heart failure without causing either clinically significant hypernatremia or an adverse affect on renal function," concludes the team.
By Sally Robertson, medwireNews Reporter