bumetanide
The mode of action has been determined through various clearance studies in both humans and experimental animals. Bumex inhibits sodium reabsorption in the ascending limb of the loop of Henle, as shown by marked reduction of free-water clearance (CH2O) during hydration and tubular free-water reabsorption (TCH2O) during hydropenia. Reabsorption of chloride in the ascending limb is also blocked by Bumex, and Bumex is somewhat more chloruretic than natriuretic.
Bumex tablets are indicated for the treatment of edema associated with congestive heart failure, hepatic and renal disease, including the nephrotic syndrome.
The usual total daily dosage of Bumex tablets is 0.5 mg to 2 mg and in most patients is given as a single dose.
The most frequent clinical adverse reactions considered probably or possibly related to Bumex are muscle cramps (seen in 1.1% of treated patients), dizziness (1.1%), hypotension (0.8%), headache (0.6%), nausea (0.6%) and encephalopathy (in patients with pre-existing liver disease) (0.6%). Serious skin reactions (i.e., Stevens-Johnson syndrome, toxic epidermal necrolysis) have been reported in association with bumetanide use.
Bumex is contraindicated in anuria. Although Bumex can be used to induce diuresis in renal insufficiency, any marked increase in blood urea nitrogen or creatinine, or the development of oliguria during therapy of patients with progressive renal disease, is an indication for discontinuation of treatment with Bumex. Bumex is also contraindicated in patients in hepatic coma or in states of severe electrolyte depletion until the condition is improved or corrected. Bumex is contraindicated in patients hypersensitive to this drug.
Excessive doses or too frequent administration can lead to profound water loss, electrolyte depletion, dehydration, reduction in blood volume and circulatory collapse with the possibility of vascular thrombosis and embolism, particularly in elderly patients.
In patients with hepatic cirrhosis and ascites, sudden alterations of electrolyte balance may precipitate hepatic encephalopathy and coma.
Serum potassium should be measured periodically and potassium supplements or potassium sparing diuretics added if necessary. Periodic determinations of other electrolytes are advised in patients treated with high doses or for prolonged periods, particularly in those on low-salt diets.
Bumex® (bumetanide) is a loop diuretic available as 0.5 mg (light green), 1 mg (yellow) and 2 mg (peach) tablets for oral administration; each tablet also contains anhydrous lactose, magnesium stearate, microcrystalline cellulose, pregelatinized starch and talc, with the following dye systems: 0.5 mg—D&C Yellow No. 10 aluminum lake and FD&C Blue No. 1 aluminum lake; 1 mg—D&C Yellow No. 10 aluminum lake; 2 mg—red iron oxide.