Comparison of Changes in Plasma Volume and Renal Function between Acetazolamide and Conventional Diuretics: Understanding the Mechanical Differences according to the "Chloride Theory".

OBJECTIVE

We compared the effects of the chloride-regaining diuretic acetazolamide with those of conventional diuretics on plasma volume, serum electrolytes, and renal function in acutely decompensated heart failure (HF) patients.

METHODS

A retrospective analysis was performed on the data of 13 patients treated with acetazolamide (Group A) and 13 patients with conventional diuretics (Group B) matched based on diuresis-induced weight reduction (≥1 kg) during resolution of worsening HF. Changes in plasma volume (Strauss formula), renal function, and serum electrolytes under treatment were determined by peripheral blood tests.

RESULTS

Clinical characteristics at baseline were not different between groups A and B. After diuretic therapy, body weight reduction (-2.23 ± 1.11 vs. -2.22 ± 1.06 kg, p = 0.97) and the number of residual HF-related signs (0.31 ± 0.48 vs. 0.23 ± 0.44, p = 0.67) was not different between groups. After each treatment, the serum chloride concen-tration increased in Group A, but decreased in Group B (+5.31 ± 4.91 vs. - 4.54 ± 4.68 mEq/L, p < 0.0001). Plasma volume (0.63 ± 13.1 vs. -12.1 ± 10.5%, p < 0.01) and renal function determined by changes in serum creatinine concentration (0.048 ± 0.12 vs. 0.21 ± 0.24 mg/dL, p < 0.047) were preserved in Group A compared with Group B.

CONCLUSIONS

While both groups exhibited equivalent body weight reduction and resolution of HF-related signs after each diuretic treatment, acetazolamide treatment preserved plasma volume and renal function compared to conventional diuretics.