Furosemide

A to Z Drug Facts

Furosemide

	Action
	Indications
	Contraindications
	Route/Dosage
	Interactions
	Lab Test Interferences
	Adverse Reactions
	Precautions
Patient Care Considerations
	Administration/Storage
	Assessment/Interventions
	Patient/Family Education

(fyu-ROH-se-mide)

Lasix, Apo-Furosemide, Furoside, Novo-Semide

Class: Loop diuretic

Action Inhibits reabsorption of sodium and chloride in proximal and distal tubules and loop of Henle.

Indications Treatment of edema associated with CHF, hepatic cirrhosis, and renal disease; hypertension.

Contraindications Hypersensitivity to sulfonylureas; anuria.

Route/Dosage

Edema

ADULTS: PO 20 to 80 mg/day as a single dose; may titrate up to 600 mg/day. IV/IM 20 to 40 mg qd or bid.

Hypertension

ADULTS: PO 40 mg bid. Maximum dose: 6 mg/kg.

CHF and Chronic Renal Failure

ADULTS: PO Up to 2 to 2.5 g/day. IV Up to 2 to 2.5 g/day. Maximum IV bolus: 1 g/day over 30 min.

Acute Pulmonary Edema

ADULTS: IV 40 mg (over 1 to 2 min). If response not satisfactory within 1 hr, increase to 80 mg. INFANTS & CHILDREN: PO Usual dose: 0.5 to 2 mg/kg qd or bid. Maximum dose: 6 mg/kg. IV/IM Usual dose: 1 mg/kg. Maximum dose 6 mg/kg.

Interactions

Aminoglycosides: May increase auditory toxicity. Charcoal: May reduce absorption of furosemide. Cisplatin: May cause additive ototoxicity. Digitalis glycosides: Electrolyte disturbances may predispose to digitalis-induced arrhythmias. Lithium: May increase plasma lithium levels and toxicity. Nonsteroidal anti-inflammatory drugs: May decrease effects of furosemide. Phenytoin: May reduce diuretic effects of furosemide. Salicylates: May impair diuretic response in patients with cirrhosis and ascites. Thiazide diuretics: Synergistic effects that may result in profound diuresis and serious electrolyte abnormalities. INCOMPATIBILITIES: Gentamicin, milrinone, or netilmicin in D5W or normal saline: Do not add to furosemide solution; precipitate forms. Highly acidic solutions of pH < 5.5: Do not mix with furosemide solution.

Lab Test Interferences None well documented.

Adverse Reactions

CV: Orthostatic hypotension; thrombophlebitis; chronic aortitis. CNS: Vertigo; headache; dizziness; paresthesia; restlessness; fever. DERM: Photosensitivity; urticaria; pruritus; necrotizing angiitis (eg, vasculitis, cutaneous vasculitis); exfoliative dermatitis; erythema multiforme; rash; occasionally, local irritation and pain with parenteral use. EENT: Blurred vision; xanthopsia (yellow vision); tinnitus; hearing impairment. GI: Anorexia; nausea; vomiting; diarrhea; oral and gastric irritation; cramping; constipation; pancreatitis. GU: Urinary bladder spasm; interstitial nephritis; glycosuria. HEMA: Anemia; leukopenia; purpura; aplastic anemia; thrombocytopenia; agranulocytosis. HEPA: Jaundice; ischemic hepatitis. META: Hyperuricemia; hyperglycemia; hypokalemia; metabolic alkalosis. OTHER: Muscle spasm; weakness.

Precautions

Pregnancy: Category C. Lactation: Excreted in breast milk. Children: May increase incidence of patent ductus arteriosus in premature infants with respiratory distress syndrome, especially in first few weeks of life. Dehydration: Excessive diuresis may cause dehydration and decreased blood volume with circulatory collapse and possible vascular thrombosis and embolism, especially in elderly. Diarrhea: Furosemide solution vehicle contains sorbitol and may induce diarrhea, especially in children. Hepatic cirrhosis and ascites: Sudden alterations of electrolyte balance may precipitate hepatic encephalopathy and coma; monitor carefully. Hypersensitivity: Patients with known sulfonamide sensitivity may show allergic reactions to furosemide. Ototoxicity: Associated with rapid injection, severe renal impairment, very large doses, or concurrent use of other ototoxic drugs. Photosensitivity: Photosensitization may occur. Renal impairment: If severe effects occur, may need to discontinue. If high-dose parenteral therapy is used, controlled IV infusion is advised. Systemic lupus erythematosus: May be exacerbated or activated.

PATIENT CARE CONSIDERATIONS

Administration/Storage

Administer oral medication with food to prevent GI irritation.
Administer qd dose in morning and bid doses at 8 AM and 2 PM to avoid nocturia and sleep disturbance.
Do not exceed infusion rate of 4 mg/min in adults.
Use infusion solutions mixed with cefoperazone sodium in 5% Dextrose within 24 hr if stored at room temperature and within 5 days if kept refrigerated.
Do not use if discolored.
Store medication at room temperature; avoid excessive exposure to light.

Assessment/Interventions

Obtain patient history, including drug history and any known allergies. Note renal or hepatic impairment, systemic lupus erythematosus, hearing impairment or hypersensitivity to sulfonamides.
Obtain baseline hearing evaluation.
Ensure that baseline BP; apical pulse; weight; serum electrolyte, calcium, glucose, uric acid, CO₂, BUN and serum creatine levels; CBC; and liver and renal function tests have been obtained before beginning therapy and monitor regularly.
Monitor I&O and weigh patient daily.
Monitor renal function and notify physician if increasing azotemia, oliguria, or increases in BUN or creatinine occur.
Notify physician if sudden alteration in fluid and electrolyte status is noted.
Monitor for signs and symptoms of hypokalemia.

OVERDOSAGE: SIGNS & SYMPTOMS
	Acute profound water loss, volume and electrolyte depletion, dehydration, reduction of blood volume, circulatory collapse with possibility of vascular thrombosis and embolism

Patient/Family Education

Instruct patient to take medication early in day to avoid disruption of sleep from increased urination and to take with food or milk to avoid GI upset.
Teach patient to take and monitor pulse daily, especially if patient is taking cardiac drugs in addition to furosemide.
Advise patient to eat diet high in potassium. Provide list of suggested foods (eg, baked potato, bananas, cantaloupe, avocados, dates, raisins, orange juice, peaches, watermelon).
Emphasize importance of follow-up visits and frequent assessment of BP while taking drug.
Advise patient to control hypertension through weight loss, sodium restriction, and exercise.
Explain to diabetic patients that drug may increase blood glucose levels and affect urine glucose test results, and that glucose levels should be monitored carefully.
For patients taking furosemide to lower BP, explain that they may feel fatigued during the first few weeks of therapy. Instruct patient to continue taking drug, but to consult with physician if problem persists.
Instruct patient to report the following symptoms to physician: Indication of weakness, dizziness, mental confusion, anorexia, lethargy, vomiting, cramps, persistent headache or fever, abdominal pain, diarrhea, rapid or irregular heart beat, yellowing of skin or eyes, or dyspnea.
Caution patient to avoid sudden position changes to prevent orthostatic hypotension.
Advise patient to avoid exposure to sunlight and to use sunscreens or wear protective clothing to avoid photosensitivity reaction.
Instruct patient not to take aspirin or otc medications without consulting physician.