Lasix Side Effects

Lasix (furosemide) is a potent diuretic (water pill) used to treat excess accumulation of fluid or swelling of the body (edema) caused by cirrhosis, chronic kidney failure, heart failure, and kidney disease. Furosemide is also used in conjunction with other blood pressure medications to treat high blood pressure (hypertension).

Serious side effects of furosemide include severe anaphylactic shock, necrotizing angiitis, interstitial nephritis, hearing loss, anemia, low white blood cells, low blood platelets, eosinophilia, Steven-Johnson syndrome, heart reactions like orthostatic hypotension (fainting or dizziness when standing up), and an increase in triglyceride and cholesterol levels.

Drug interactions of furosemide include aminoglycoside antibiotics, ethacrynic acid, aspirin, lithium, sucralfate, other antihypertensive drugs, nonsteroidal anti-inflammatory drugs (NSAIDs), cisplatin, cyclosporine, methotrexate, phenytoin, antibiotics, heart medications, laxatives, and steroids. Furosemide should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus. Furosemide is secreted in breast milk. Nursing mothers should avoid breastfeeding while taking furosemide.

Common side effects of Lasix are:

• electrolyte depletion (for example, sodium, potassium).

Other important side effects include:

• jaundice,
• ringing in the ears (tinnitus),
• sensitivity to light (photophobia),
• rash,
• pancreatitis,
• nausea,
• diarrhea,
• abdominal pain, and
• dizziness.

Increased blood sugar and uric acid levels also may occur.

Profound diuresis with water and electrolyte depletion can occur if Lasix is given in excess amounts. Other side effects and adverse effects of this medicine include:

• Gut (gastrointestinal or GI) reactions like pancreatitis, jaundice, anorexia, cramping, diarrhea, constipation, nausea, and vomiting
• Systemic hypersensitivity reactions like severe anaphylactic shock, necrotizing angiitis, and interstitial nephritis
• Central nervous system (CNS) reactions like vertigo, headaches, blurred vision, tinnitus, and hearing loss
• Blood reactions like anemia, leukopenia, thrombocytopenia, and eosinophilia
• Hypersensitive skin reactions like rash, itching, hives, photosensitivity, exfoliative dermatitis, and Steven-Johnson syndrome
• Heart reactions like orthostatic hypotension (fainting or dizziness when standing up) and an increase in triglyceride and cholesterol levels

Other reactions include:

• weakness,
• muscle spasms,
• thrombophlebitis,
• fever, and
• hyperglycemia (high blood sugar).

• Lasix may increase the ototoxic potential of aminoglycoside antibiotics, especially in the presence of impaired renal function. Except in life-threatening situations, avoid this combination.
• Lasix should not be used concomitantly with ethacrynic acid because of the possibility of ototoxicity. Patients receiving high doses of salicylates concomitantly with Lasix, 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 Lasix are given concomitantly. In addition, nephrotoxicity of nephrotoxic drugs such as cisplatin may be enhanced if Lasix is not given in lower doses and with positive fluid balance when used to achieve forced diuresis during cisplatin treatment.
• Lasix 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.
• Lasix 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 Lasix, angiotensin converting enzyme inhibitors, or angiotensin receptor blockers may be necessary.
• Potentiation occurs with ganglionic or peripheral adrenergic blocking drugs.
• Lasix may decrease arterial responsiveness to norepinephrine. However, norepinephrine may still be used effectively.
• Simultaneous administration of sucralfate and Lasix tablets may reduce the natriuretic and antihypertensive effects of Lasix. Patients receiving both drugs should be observed closely to determine if the desired diuretic and/or antihypertensive effect of Lasix is achieved. The intake of Lasix and sucralfate should be separated by at least two hours.
• In isolated cases, intravenous administration of Lasix within 24 hours of taking chloral hydrate may lead to flushing, sweating attacks, restlessness, nausea, increase in blood pressure, and tachycardia. Use of Lasix concomitantly with chloral hydrate is therefore not recommended.
• Phenytoin interferes directly with renal action of Lasix. There is evidence that treatment with phenytoin leads to decrease intestinal absorption of Lasix, and consequently to lower peak serum furosemide concentrations.
• Methotrexate and other drugs that, like Lasix, undergo significant renal tubular secretion may reduce the effect of Lasix. Conversely, Lasix may decrease renal elimination of other drugs that undergo tubular secretion. High-dose treatment of both Lasix and these other drugs may result in elevated serum levels of these drugs and may potentiate their toxicity as well as the toxicity of Lasix.
• Lasix can increase the risk of cephalosporin-induced nephrotoxicity even in the setting of minor or transient renal impairment.
• Concomitant use of cyclosporine and Lasix is associated with increased risk of gouty arthritis secondary to Lasix-induced hyperurecemia and cyclosporine impairment of renal urate excretion.
• High doses ( > 80 mg) of furosemide may inhibit the binding of thyroid hormones to carrier proteins and result in transient increase in free thyroid hormones, followed by an overall decrease in total thyroid hormone levels.
• One study in six subjects demonstrated that the combination of furosemide and acetylsalicylic acid temporarily reduced creatinine clearance in patients with chronic renal insufficiency. There are case reports of patients who developed increased BUN, serum creatinine and serum potassium levels, and weight gain when furosemide was used in conjunction with NSAIDs.
• Literature reports indicate that coadministration of indomethacin may reduce the natriuretic and antihypertensive effects of Lasix (furosemide) in some patients by inhibiting prostaglandin synthesis. Indomethacin may also affect plasma renin levels, aldosterone excretion, and renin profile evaluation. Patients receiving both indomethacin and Lasix should be observed closely to determine if the desired diuretic and/or antihypertensive effect of Lasix is achieved.

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. pruritis
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, Lasix dosage should be reduced or the therapy should be withdrawn.