Furosemide is easily absorbed from the intestinal tract and begins to act in 30 to 60 minutes after oral administration. It is a loop diuretic which inhibits reabsorption of sodium and chloride in the kidneys, enhancing water excretion. Furosemide is indicated for the treatment of edema fluid on the lungs or in the abdomen associated with heart disease and acute noninflammatory tissue edema in dogs. In cases of edema involving heart disease, the continued use of heart stimulants is indicated.
Dosage and Administration
The usual dosage of Furosemide is 1 to 2 mg/lb body weight orally once or twice daily at 6-8 hour intervals, however this can be adjusted to the individual requirements of the animal being treated
Warnings, Side Effects and Drug Interactions
Furosemide is contraindicated in pregnant animals and may cause fetal abnormalities Furosemide is contraindicated where the animal is not passing urine, in animals allergic to the drug, in animals in a hepatic coma, or during electrolytic imbalances. The renal function, as well as levels of potassium and calcium in the blood should be monitored closely as dehydration, kidney damage and electrolyte imbalances can occur with use of the product. If given in conjunction with corticosteroids, the potassium-depletion effect of both drugs is additive. The early signs of electrolyte imbalance include: increased thirst, lethargy, drowsiness or restlessness, reduces urine production, gastrointestinal disturbances and an elevated heart rate. Potassium supplementation may be required. Excessive loss of potassium in patients receiving digitalis or its glycosides may lead to digitalis toxicity and heart arrythmias.
Diabetes may be exacerbated by furosemide. Ototoxicity resulting in transient loss of hearing has been reported with furosemide.
The concurrent use of furosemide with some antibiotics may be inadvisable as the kidney toxicity of aminoglycosides, cephalosporins and polymyxins, as well as the ototoxic effects of aminoglycosides may be increased. Sulfonamide diuretics have been reported to decrease arterial responsiveness to blood pressure raising medications and to enhance the paralytic effects of tubocurarine. It is advisable to discontinue Furosemide for one day prior to any elective surgery.