Uteric

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. Hypertensive patients who cannot be adequately controlled with thiazides will probably also not be adequately controlled with furosemide alone.

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. The individually determined single dose should then be given once or twice daily (e.g., at 8 am and 2 pm). The dose of furosemide tablets may be carefully titrated up to 600 mg/day in patients with clinically severe edematous states. Edema may be most efficiently and safely mobilized by giving furosemide tablets on 2 to 4 consecutive days each week. When doses exceeding 80 mg/day are given for prolonged periods, careful clinical observation and laboratory monitoring are particularly advisable (see PRECAUTIONS: Laboratory Tests ). Geriatric Patients: In general, dose selection for the elderly patient should be cautious, usually starting at the low end of the dosing range (see PRECAUTIONS: Geriatric Use ). Pediatric Patients: The usual initial dose of oral furosemide in pediatric patients is 2 mg/kg body weight, given as a single dose. If the diuretic response is not satisfactory after the initial dose, dosage may be increased by 1 or 2 mg/kg no sooner than 6 to 8 hours after the previous dose. Doses greater than 6 mg/kg body weight are not recommended. For maintenance therapy in pediatric patients, the dose should be adjusted to the minimum effective level. Hypertension Therapy should be individualized according to the patient's response to gain maximal therapeutic response and to determine the minimal dose needed to maintain the therapeutic response. Adults: The usual initial dose of furosemide…

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. Plasma concentrations ranging from 1 to 400 mcg/mL are 91 to 99% bound in healthy individuals. The unbound fraction averages 2.3 to 4.1% at therapeutic concentrations. The onset of diuresis following oral administration is within 1 hour. The peak effect occurs within the first or second hour. The duration of diuretic effect is 6 to 8 hours. In fasted normal men, the mean bioavailability of furosemide from furosemide tablets and furosemide oral solution is 64% and 60%, respectively, of that from an intravenous injection of the drug. Although furosemide is more rapidly absorbed from the oral solution (50 minutes) than from the tablet (87 minutes), peak plasma levels and area under the plasma concentration-time curves do not differ significantly. Peak plasma concentrations increase with increasing dose but times-to-peak do not differ among doses. The terminal half-life of furosemide is approximately 2 hours. Significantly more furosemide is excreted in urine following the IV injection than after the tablet or oral solution. There are no significant differences between the two oral formulations in the amount of unchanged drug excreted in urine. Geriatric Population Furosemide binding to albumin may…

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 2. pancreatitis 3. jaundice (intrahepatic cholestatic jaundice) 4. increased liver enzymes 5. anorexia 6. oral and gastric irritation 7. cramping 8. diarrhea 9. constipation 10. nausea 11. vomiting Systemic Hypersensitivity Reactions 1. severe anaphylactic or anaphylactoid reactions (e.g., with shock) 2. systemic vasculitis 3. interstitial nephritis 4. necrotizing angiitis Central Nervous System Reactions 1. tinnitus and hearing loss 2. paresthesias 3. vertigo 4. dizziness 5. headache 6. blurred vision 7. xanthopsia Hematologic Reactions 1. aplastic anemia 2. thrombocytopenia 3. agranulocytosis 4. hemolytic anemia 5. leukopenia 6. anemia 7. eosinophilia Dermatologic-Hypersensitivity Reactions 1. toxic epidermal necrolysis 2. Stevens-Johnson Syndrome 3. erythema multiforme 4. drug rash with eosinophilia and systemic symptoms 5. acute generalized exanthematous pustulosis 6. exfoliative dermatitis 7. bullous pemphigoid 8. purpura 9. photosensitivity 10. rash 11. pruritus 12. urticaria Cardiovascular Reaction 1. Orthostatic hypotension may occur and be aggravated by alcohol, barbiturates or narcotics. 2. Increase in cholesterol and triglyceride serum levels Other Reactions 1. hyperglycemia 2. glycosuria 3. hyperuricemia 4. muscle spasm 5. weakness 6. restlessness 7. urinary bladder spasm 8. thrombophlebitis 9. fever Whenever adverse reactions are moderate or severe, furosemide dosage should be reduced or therapy withdrawn.

CONTRAINDICATIONS Furosemide tablets are contraindicated in patients with anuria and in patients with a history of hypersensitivity to furosemide.

WARNING Furosemide is a potent diuretic which, if given in excessive amounts, can lead to a profound diuresis with water and electrolyte depletion. Therefore, careful medical supervision is required and dose and dose schedule must be adjusted to the individual patient's needs (see DOSAGE AND ADMINISTRATION ).

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. There is a risk of ototoxic effects if cisplatin and furosemide are given concomitantly. In addition, nephrotoxicity of nephrotoxic drugs such as cisplatin may be enhanced if furosemide is not given in lower doses and with positive fluid balance when used to achieve forced diuresis during cisplatin treatment. Furosemide has a tendency to antagonize the skeletal muscle relaxing effect of tubocurarine and may potentiate the action of succinylcholine. Lithium generally should not be given with diuretics because they reduce lithium's renal clearance and add a high risk of lithium toxicity. Furosemide combined with angiotensin converting enzyme inhibitors or angiotensin II receptor blockers may lead to severe hypotension and deterioration in renal function, including renal failure. An interruption or reduction in the dosage of furosemide, angiotensin converting enzyme inhibitors, or angiotensin receptor blockers may be necessary. Potentiation occurs with ganglionic or peripheral adrenergic blocking drugs. Furosemide may decrease arterial responsiveness to norepinephrine. However, norepinephrine may still be used effectively. Simultaneous administration of sucralfate and furosemide tablets may reduce the natriuretic and antihypertensive effects of furosemide. Patients receiving both drugs should be observed closely to determine if the desired diuretic and/or antihypertensive effect of furosemide is achieved. The intake of furosemide and sucralfate should be…