furosemide (fur-oh-se-mide) Lasix

 Indications

Edema due to heart failure, hepatic impairment, or renal

disease. Hypertension.

Action

Inhibits the reabsorption of sodium and chloride from

the loop of Henle and distal renal tubule. Increases renal

excretion of water, sodium, chloride, magnesium,

potassium, and calcium. Effectiveness persists in impaired

renal function. Therapeutic Effects: Diuresis

and subsequent mobilization of excess fluid (edema,

pleural effusions). Decreased BP.

Pharmacokinetics

Absorption: 60–67% absorbed after oral administration

(pin acute HF and in renal failure); also absorbed

from IM sites.

Distribution: Crosses placenta, enters breast milk.

Protein Binding: 91–99%.

Metabolism and Excretion: Minimally metabolized

by liver, some nonhepatic metabolism, some renal

excretion as unchanged drug.

Half-life: 30–60 min (qin renal impairment).

TIME/ACTION PROFILE (diuretic effect)

ROUTE ONSET PEAK DURATION

PO 30–60 min 1–2 hr 6–8 hr

IM 10–30 min unknown 4–8 hr

IV 5 min 30 min 2 hr

Contraindications/Precautions

Contraindicated in: Hypersensitivity; Cross-sensitivity

with thiazides and sulfonamides may occur; Hepatic

coma or anuria; Some liquid products may contain

alcohol, avoid in patients with alcohol intolerance.

Use Cautiously in: Severe liver disease (may precipitate

hepatic coma; concurrent use with potassiumsparing

diuretics may be necessary); Electrolyte depletion;

Diabetes mellitus; Hypoproteinemia (qrisk of

ototoxicity); Severe renal impairment (qrisk of ototoxicity);

OB, Lactation: Safety not established; Pedi:qrisk

for renal calculi and patent ductus arteriosis in premature

neonates; Geri: May haveqrisk of side effects, especially

hypotension and electrolyte imbalance, at usual

doses.

Adverse Reactions/Side Effects

CNS: blurred vision, dizziness, headache, vertigo.

EENT: hearing loss, tinnitus. CV: hypotension. GI:

anorexia, constipation, diarrhea, dry mouth, dyspepsia,

qliver enzymes, nausea, pancreatitis, vomiting. GU:q

BUN, excessive urination, nephrocalcinosis. Derm:

ERYTHEMA MULTIFORME, STEVENS-JOHNSON SYNDROME,

TOXIC EPIDERMAL NECROLYSIS, photosensitivity, pruritis,

rash, urticaria. Endo: hypercholesterolemia, hyperglycemia,

hypertriglyceridemia, hyperuricemia. F and E:

dehydration, hypocalcemia, hypochloremia, hypokalemia,

hypomagnesemia, hyponatremia, hypovolemia,

metabolic alkalosis. Hemat: APLASTIC ANEMIA, AGRANULOCYTOSIS,

hemolytic anemia, leukopenia, thrombocytopenia.

MS: muscle cramps. Neuro: paresthesia.

Misc: fever.

Interactions

Drug-Drug:qrisk of hypotension with antihypertensives,

nitrates, or acute ingestion of alcohol.

qrisk of hypokalemia with other diuretics, amphotericin

B, stimulant laxatives, and

corticosteroids. Hypokalemia mayqrisk of digoxin

toxicity andqrisk of arrhythmia in patients taking

drugs that prolong the QT interval.plithium excretion,

may cause lithium toxicity.qrisk of ototoxicity with aminoglycosides or cisplatin.qrisk of nephrotoxicity

with cisplatin. NSAIDSpeffects of furosemide.

Mayqrisk of methotrexate toxicity.peffects of

furosemide when given at same time as sucralfate,

cholestyramine, or colestipol.qrisk of salicylate

toxicity (with use of high-dose salicylate therapy).

Concurrent use with cyclosporine mayqrisk of gouty

arthritis.

Route/Dosage

Edema

PO (Adults): 20–80 mg/day as a single dose initially,

may repeat in 6–8 hr; mayqdose by 20–40 mg q 6–8

hr until desired response. Maintenance doses may be

given once or twice daily (doses up to 2.5 g/day have

been used in patients with HF or renal disease). Hypertension—

40 twice daily initially (when added to regimen,

pdose of other antihypertensives by 50%); adjust

further dosing based on response; Hypercalcemia—

120 mg/day in 1–3 doses.

PO (Children 1 mo): 2 mg/kg as a single dose; may

beqby 1–2 mg/kg q 6–8 hr (maximum dose6

mg/kg).

PO (Neonates): 1–4 mg/kg/dose 1–2 times/day.

IM, IV (Adults): 20–40 mg, may repeat in 1–2 hr

andqby 20 mg every 1–2 hr until response is obtained,

maintenance dose may be given q 6–12 hr;

Continuous infusion—Bolus 0.1 mg/kg followed by

0.1 mg/kg/hr, double q 2 hr to a maximum of 0.4 mg/

kg/hr.

IM, IV (Children): 1–2 mg/kg/dose q 6–12 hr; Continuous

infusion—0.05 mg/kg/hr, titrate to clinical

effect.

IM, IV (Neonates): 1–2 mg/kg/dose q 12–24 hr.

Hypertension

PO (Adults): 40 twice daily initially (when added to

regimen,pdose of other antihypertensives by 50%);

adjust further dosing based on response.

Availability (generic available)

Tablets: 20 mg, 40 mg, 80 mg, 500 mg. Cost: Generic—

20 mg $6.50/100, 40 mg $7.11/100, 80 mg

$10.83/100. Oral solution (10 mg/mL—orange

flavor, 8 mg/mL—pineapple—peach flavor): 8

mg/mL, 10 mg/mL. Cost: Generic—10 mg/mL

$10.40/60 mL. Solution for injection: 10 mg/mL.