FUROSEMIDE Drug Interactions: What You Need to Know

INTERACTIONS Aminoglycoside antibiotics : Increased potential ototoxicity of the antibiotics. Avoid combination. ( 7.1 ) Ethacrynic acid : Risk of ototoxicity. Avoid combination. ( 7.1 ) Salicylates : Risk of salicylate toxicity. ( 7.1 ) Cisplatin and nephrotoxic drugs : Risk of ototoxicity and nephrotoxicity. ( 7.1 ) Lithium : Risk of lithium toxicity. ( 7.1 ) Renin-angiotensin inhibitors : Increased risk of hypotension and renal failure. ( 7.1 ) Adrenergic blocking drugs : Risk of potentiation. ( 7.1 ) Drugs undergoing renal tubular secretion : Risk of toxicity potentiation. ( 7.1 )

7.1 Effects of Furosemide on Other Drugs Table 1: Effects of Furosemide on Other Drugs Drug/Substance Class or Name Drug Interaction Effect Recommendations Aminoglycoside antibiotics Furosemide may increase the ototoxic potential of aminoglycoside antibiotics, especially in the presence of impaired renal function <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.3 )]</span>. Avoid combination except in life-threatening situations. Ethacrynic acid Possibility of ototoxicity <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.3 )]</span>. Avoid concomitant use with ethacrynic acid.

Salicylates

May experience salicylate toxicity at lower doses because of competitive renal excretory sites. Monitor for symptoms of salicylate toxicity.

Cisplatin

Cisplatin and nephrotoxic drugs There is a risk of ototoxic effects if cisplatin and furosemide are given concomitantly [see Warnings and Precautions ( 5.3 )].

Nephrotoxicity

Administer furosemide at lower doses and with positive fluid balance when used to achieve forced diuresis during cisplatin treatment. Monitor renal function. Paralytic agents Furosemide has a tendency to antagonize the skeletal muscle relaxing effect of tubocurarine and may potentiate the action of succinylcholine. Monitor for skeletal muscle effect.

Lithium

Furosemide reduces lithium’s renal clearance and adds a high-risk of lithium toxicity. Avoid concomitant use with lithium. Angiotensin converting enzyme inhibitors or angiotensin II receptor blockers May lead to severe hypotension and deterioration in renal function, including renal failure. Monitor for changes in blood pressure and renal function and interrupt or reduce the dosage of furosemide, angiotensin converting enzyme inhibitors, or angiotensin receptor blockers if needed. Antihypertensive drugs Furosemide may add to or potentiate the therapeutic effect of other antihypertensive drugs. Monitor for changes in blood pressure and adjust the dose of other antihypertensive drugs if needed. Adrenergic blocking drugs or peripheral adrenergic blocking drugs Potentiation occurs. Monitor for changes in blood pressure and adjust the dose of adrenergic blocking drugs if needed.

Norepinephrine

Furosemide may decrease arterial responsiveness (vasoconstricting effect) to norepinephrine. Monitor blood pressure (or mean arterial pressure). Chloral hydrate In isolated cases, intravenous administration of furosemide within 24 hours of taking chloral hydrate may lead to flushing, sweating attacks, restlessness, nausea, increase in blood pressure, and tachycardia. Concomitant use with chloral hydrate is not recommended. Methotrexate and other drugs undergoing renal tubular secretion Furosemide may decrease renal elimination of other drugs that undergo tubular secretion. High-dose treatment of furosemide may result in elevated serum levels of these drugs and may potentiate their toxicity. Monitor serum levels of drugs undergoing renal tubular secretion and adjust the dose if needed.

Cephalosporin

Furosemide can increase the risk of cephalosporin-induced nephrotoxicity even in the setting of minor or transient renal impairment. Monitor for changes in renal function.

Cyclosporine

Increased risk of gouty arthritis secondary to furosemide-induced hyperuricemia and cyclosporine impairment of renal urate excretion. Monitor serum urate levels. Thyroid hormones 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. Monitor the total thyroid hormone levels.

7.2 Effect of Other Drugs on Furosemide Table 2: Effect of Other Drugs on Furosemide Drug/Substance Class or Name Drug Interaction Effect Recommendations Phenytoin Phenytoin interferes directly with renal action of furosemide. Monitor diuretic effects of furosemide and adjust the dose of furosemide if needed. Methotrexate and other drugs undergoing renal tubular secretion May reduce the effect of furosemide. High-dose treatment of methotrexate and these other drugs may result in elevated serum levels of furosemide and may potentiate the toxicity of furosemide. Monitor for enhanced toxicity of furosemide.

Indomethacin

Coadministration of indomethacin may reduce the natriuretic and antihypertensive effects of 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 furosemide should be observed closely to determine if the desired diuretic and/or antihypertensive effect of furosemide is achieved.

7.1 Effects of Furosemide on Other Drugs Table 1: Effects of Furosemide on Other Drugs Drug/Substance Class or Name Drug Interaction Effect Recommendations Aminoglycoside antibiotics Furosemide may increase the ototoxic potential of aminoglycoside antibiotics, especially in the presence of impaired renal function <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.3 )]</span>. Avoid combination except in life-threatening situations. Ethacrynic acid Possibility of ototoxicity <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.3 )]</span>. Avoid concomitant use with ethacrynic acid.

Salicylates

May experience salicylate toxicity at lower doses because of competitive renal excretory sites. Monitor for symptoms of salicylate toxicity.

Cisplatin

Cisplatin and nephrotoxic drugs There is a risk of ototoxic effects if cisplatin and furosemide are given concomitantly [see Warnings and Precautions ( 5.3 )].

Nephrotoxicity

Administer furosemide at lower doses and with positive fluid balance when used to achieve forced diuresis during cisplatin treatment. Monitor renal function. Paralytic agents Furosemide has a tendency to antagonize the skeletal muscle relaxing effect of tubocurarine and may potentiate the action of succinylcholine. Monitor for skeletal muscle effect.

Lithium

Furosemide reduces lithium’s renal clearance and adds a high-risk of lithium toxicity. Avoid concomitant use with lithium. Angiotensin converting enzyme inhibitors or angiotensin II receptor blockers May lead to severe hypotension and deterioration in renal function, including renal failure. Monitor for changes in blood pressure and renal function and interrupt or reduce the dosage of furosemide, angiotensin converting enzyme inhibitors, or angiotensin receptor blockers if needed. Antihypertensive drugs Furosemide may add to or potentiate the therapeutic effect of other antihypertensive drugs. Monitor for changes in blood pressure and adjust the dose of other antihypertensive drugs if needed. Adrenergic blocking drugs or peripheral adrenergic blocking drugs Potentiation occurs. Monitor for changes in blood pressure and adjust the dose of adrenergic blocking drugs if needed.

Norepinephrine

Furosemide may decrease arterial responsiveness (vasoconstricting effect) to norepinephrine. Monitor blood pressure (or mean arterial pressure). Chloral hydrate In isolated cases, intravenous administration of furosemide within 24 hours of taking chloral hydrate may lead to flushing, sweating attacks, restlessness, nausea, increase in blood pressure, and tachycardia. Concomitant use with chloral hydrate is not recommended. Methotrexate and other drugs undergoing renal tubular secretion Furosemide may decrease renal elimination of other drugs that undergo tubular secretion. High-dose treatment of furosemide may result in elevated serum levels of these drugs and may potentiate their toxicity. Monitor serum levels of drugs undergoing renal tubular secretion and adjust the dose if needed.

Cephalosporin

Furosemide can increase the risk of cephalosporin-induced nephrotoxicity even in the setting of minor or transient renal impairment. Monitor for changes in renal function.

Cyclosporine

Increased risk of gouty arthritis secondary to furosemide-induced hyperuricemia and cyclosporine impairment of renal urate excretion. Monitor serum urate levels. Thyroid hormones 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. Monitor the total thyroid hormone levels.

7.2 Effect of Other Drugs on Furosemide Table 2: Effect of Other Drugs on Furosemide Drug/Substance Class or Name Drug Interaction Effect Recommendations Phenytoin Phenytoin interferes directly with renal action of furosemide. Monitor diuretic effects of furosemide and adjust the dose of furosemide if needed. Methotrexate and other drugs undergoing renal tubular secretion May reduce the effect of furosemide. High-dose treatment of methotrexate and these other drugs may result in elevated serum levels of furosemide and may potentiate the toxicity of furosemide. Monitor for enhanced toxicity of furosemide.

Indomethacin

Coadministration of indomethacin may reduce the natriuretic and antihypertensive effects of 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 furosemide should be observed closely to determine if the desired diuretic and/or antihypertensive effect of furosemide is achieved.

Lasix ONYU is contraindicated in patients with anuria. Lasix ONYU is contraindicated in patients with a history of hypersensitivity to furosemide, any component of the Lasix ONYU formulation, or medical adhesives. Anuria. ( 4 ) Hypersensitivity to furosemide or medical adhesives. ( 4 )

AND PRECAUTIONS Fluid, Electrolyte, and Metabolic Abnormalities : Monitor serum electrolytes, CO 2 , BUN, creatinine, glucose, and uric acid. ( 5.1 )

Worsening Renal

Function : Monitor for dehydration and azotemia. ( 5.2 ) Ototoxicity : Avoid higher than recommended doses. ( 5.3 , 7.1 )

Acute Urinary

Retention : Monitor patients with symptoms of urinary retention. ( 5.4 )

Incomplete

Dosing : Fluid contact and certain patient movements during treatment may cause the On-body Infusor to prematurely terminate infusion. Ensure the patient or caregiver can detect and respond to alarms. ( 5.5 )

5.1 Fluid, Electrolyte, and Metabolic Abnormalities Furosemide may cause fluid, electrolyte, and metabolic abnormalities such as hypovolemia, hypokalemia, azotemia, hyponatremia, hypochloremic alkalosis, hypomagnesemia, hypocalcemia, hyperglycemia, or hyperuricemia, particularly in patients receiving higher doses, patients with inadequate oral electrolyte intake, and in elderly patients. Excessive diuresis may cause dehydration and blood volume reduction with circulatory collapse and possibly vascular thrombosis and embolism, particularly in elderly patients. Serum electrolytes, CO 2 , BUN, creatinine, glucose, and uric acid should be monitored frequently during furosemide therapy <span class="opacity-50 text-xs">[see Use in Specific Populations ( 8.6 )]</span> .

5.2 Worsening Renal Function Furosemide can cause dehydration and azotemia. If increasing azotemia and oliguria occur during treatment of severe progressive renal disease, discontinue furosemide <span class="opacity-50 text-xs">[see Clinical Pharmacology ( 12.3 )]</span>.

5.3 Ototoxicity Cases of tinnitus and reversible or irreversible hearing impairment and deafness have been reported with furosemide. Reports usually indicate that furosemide ototoxicity is associated with rapid injection, severe renal impairment, the use of higher than recommended doses, hypoproteinemia or concomitant therapy with aminoglycoside antibiotics, ethacrynic acid, or other ototoxic drugs. If the physician elects to use high-dose parenteral therapy, controlled intravenous infusion is advisable (for adults, an infusion rate not exceeding 4 mg furosemide per minute has been used) <span class="opacity-50 text-xs">[see Drug Interactions ( 7.1 )]</span>.

5.4 Acute Urinary Retention In patients with severe symptoms of urinary retention (because of bladder emptying disorders, prostatic hyperplasia, urethral narrowing), the administration of furosemide can cause acute urinary retention related to increased production and retention of urine. These patients require careful monitoring, especially during the initial stages of treatment.

5.5 Incomplete Dosing The On-body Infusor should not be allowed to get wet from water or any other fluids (blood or drug product). Fluid contact with the circuit board can lead to device errors and premature termination of infusion. The On-body Infusor is intended for use in a setting where the patient can limit their activity for the duration of administration. Certain patient movements may cause interruption of device adherence to skin and premature termination of infusion. The On-body Infusor for FUROSCIX should only be administered in settings where alarms can be detected and responded to in order to ensure a complete dose is administered <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.2 )]</span> .

5.1 Fluid, Electrolyte, and Metabolic Abnormalities Furosemide may cause fluid, electrolyte, and metabolic abnormalities such as hypovolemia, hypokalemia, azotemia, hyponatremia, hypochloremic alkalosis, hypomagnesemia, hypocalcemia, hyperglycemia, or hyperuricemia, particularly in patients receiving higher doses, patients with inadequate oral electrolyte intake, and in elderly patients. Excessive diuresis may cause dehydration and blood volume reduction with circulatory collapse and possibly vascular thrombosis and embolism, particularly in elderly patients. Serum electrolytes, CO 2 , BUN, creatinine, glucose, and uric acid should be monitored frequently during furosemide therapy <span class="opacity-50 text-xs">[see Use in Specific Populations ( 8.6 )]</span> .

5.2 Worsening Renal Function Furosemide can cause dehydration and azotemia. If increasing azotemia and oliguria occur during treatment of severe progressive renal disease, discontinue furosemide <span class="opacity-50 text-xs">[see Clinical Pharmacology ( 12.3 )]</span>.

5.3 Ototoxicity Cases of tinnitus and reversible or irreversible hearing impairment and deafness have been reported with furosemide. Reports usually indicate that furosemide ototoxicity is associated with rapid injection, severe renal impairment, the use of higher than recommended doses, hypoproteinemia or concomitant therapy with aminoglycoside antibiotics, ethacrynic acid, or other ototoxic drugs. If the physician elects to use high-dose parenteral therapy, controlled intravenous infusion is advisable (for adults, an infusion rate not exceeding 4 mg furosemide per minute has been used) <span class="opacity-50 text-xs">[see Drug Interactions ( 7.1 )]</span>.

5.4 Acute Urinary Retention In patients with severe symptoms of urinary retention (because of bladder emptying disorders, prostatic hyperplasia, urethral narrowing), the administration of furosemide can cause acute urinary retention related to increased production and retention of urine. These patients require careful monitoring, especially during the initial stages of treatment.

5.5 Incomplete Dosing The On-body Infusor should not be allowed to get wet from water or any other fluids (blood or drug product). Fluid contact with the circuit board can lead to device errors and premature termination of infusion. The On-body Infusor is intended for use in a setting where the patient can limit their activity for the duration of administration. Certain patient movements may cause interruption of device adherence to skin and premature termination of infusion. The On-body Infusor for FUROSCIX should only be administered in settings where alarms can be detected and responded to in order to ensure a complete dose is administered <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.2 )]</span> .