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Medication News & Updates

      Geriatric diuretic of Choice

       For patients with renal function above 50ml/min thiazides remain the agents of choice. However, for those with CRCl rates lower than this thiazides are ineffective with the exception of metolazone (Zaroxylon) which may still be effective down to 30ml/min.

     The loop diuretics, Torsemide(Demadex), Bumetandie (Bumex), or furosemide (Lasix), should be considered for patients with creatinine clearances below 40-50ml/min. When a loop diuretic is indicated the following considerations should be made. On a weight to weight basis torsemide is twice as potent as furosemide, and provides a longer duration of action at lower urinary concentrations. This allows for a 24-hour dosage interval and avoids the paradoxical antidiuresis seen with furosemide or bumetanide. Torsemide doses of 10-20 mg are roughly equivalent to 40 mg furosemide and 1 mg bumetanide.

      Limited data suggest torsemide exhibits less pronounced effects on the excretion of calcium, magnesium, and potassium than furosemide or bumetanide, and torsemide, has shown minimal effects on sodium and potassium, however,at higher doses the distinctions may be insignificant. Reports of hyperuricemia followed clinical trials with bumetanide (18.4%), ethacrynic acid and furosemide, although exact percentage values are unknown for ethacrynic acid and furosemide. Torsemide again proved superior to these agents with no or slight increases in uric acid levels following administration during clinical trials. Torsemide is effective in the treatment of mild to moderate essential hypertension, and in the reduction of edema associated with congestive heart failure, renal disease and hepatic cirrhosis. Furosemide and bumetanide are not known to be as effective as thiazides or torsemide for blood pressure control.

The chart below shows the some basic pharmacokinetic properties of the loop diuretics for comparison.

                1 Ceiling dose: single dose above which additional response is unlikely to be observed.