Overview
DESCRIPTION Furosemide is a diuretic which is an anthranilic acid derivative. Furosemide Tablets for oral administration contain furosemide as the active ingredient and the following inactive ingredients: corn starch NF, lactose monohydrate NF, magnesium stearate NF, pregelatinized starch NF, and talc USP. Chemically, it is 4-chloro-N-furfuryl-5-sulfamoylanthranilic acid.
Mechanism of Action
CLINICAL PHARMACOLOGY Investigations into the mode of action of furosemide have utilized micropuncture studies in rats, stop flow experiments in dogs and various clearance studies in both humans and experimental animals. It has been demonstrated that furosemide inhibits primarily the absorption of sodium and chloride not only in the proximal and distal tubules but also in the loop of Henle. The high degree of efficacy is largely due to the unique site of action. The action on the distal tubule is independent of any inhibitory effect on carbonic anhydrase and aldosterone. Recent evidence suggests that furosemide glucuronide is the only or at least the major biotransformation product of furosemide in man. Furosemide is extensively bound to plasma proteins, mainly to albumin.
Indications
- INDICATIONS AND USAGE Edema Furosemide tablets are indicated in adults and pediatric patients for the treatment of edema associated with congestive heart failure, cirrhosis of the liver, and renal disease, including the nephrotic syndrome. Furosemide tablets are particularly useful when an agent with greater diuretic potential is desired. Hypertension Oral furosemide may be used in adults for the treatment of hypertension alone or in combination with other antihypertensive agents.
Common Doses
- 80 mg
- 40 mg
- 600 mg
- 2 mg
Dosage
DOSAGE AND ADMINISTRATION Edema Therapy should be individualized according to patient response to gain maximal therapeutic response and to determine the minimal dose needed to maintain that response. Adults - The usual initial dose of furosemide tablets is 20 to 80 mg given as a single dose. Ordinarily a prompt diuresis ensues. If needed, the same dose can be administered 6 to 8 hours later or the dose may be increased. The dose may be raised by 20 or 40 mg and given not sooner than 6 to 8 hours after the previous dose until the desired diuretic effect has been obtained.
Contraindications
- CONTRAINDICATIONS Furosemide tablets are contraindicated in patients with anuria and in patients with a history of hypersensitivity to furosemide.
Side Effects
- ADVERSE REACTIONS Adverse reactions are categorized below by organ system and listed by decreasing severity. Gastrointestinal System Reactions 1. hepatic encephalopathy in patients with hepatocellular insufficiency 6. oral and gastric irritation 7. cramping 2. pancreatitis 8. diarrhea 3. jaundice (intrahepatic cholestatic jaundice) 9. constipation 4. increased liver enzymes 10. nausea 5. anorexia 11. vomiting Systemic Hypersensitivity Reactions 1. severe anaphylactic or anaphylactoid reactions (e.g., with shock) 3. interstitial nephritis 2. systemic vasculitis 4.
Interactions
- Drug Interactions Furosemide may increase the ototoxic potential of aminoglycoside antibiotics, especially in the presence of impaired renal function. Except in life-threatening situations, avoid this combination. Furosemide should not be used concomitantly with ethacrynic acid because of the possibility of ototoxicity. Patients receiving high doses of salicylates concomitantly with furosemide, as in rheumatic disease, may experience salicylate toxicity at lower doses because of competitive renal excretory sites.