Interactions : אינטראקציות

4.5 Interaction with other medicinal products and other forms of interaction

Alcohol: Enhanced hypotensive effect. Orthostatic hypotension, associated with diuretics, may be enhanced.

Aldesleukin: Enhanced hypotensive effect.

Anaesthetics, general: Enhanced hypotensive effects.
Anion-exchange resins: Colestyramine and colestipol markedly reduce the absorption of furosemide. Administer two to three hours apart.

Anti-arrhythmics: Toxicity of amiodarone, disopyramide, flecainide and quinidine is increased if hypokalaemia occurs. Action of lidocaine and mexilitine is antagonised by hypokalaemia.
Hypokalaemia increases risk of ventricular arrhythmias with sotalol, a beta-blocker.

Antibacterials: Furosemide may enhance the toxicity of nephrotoxic antibiotics including some cephalosporins. It can enhance the ototoxicity of aminoglycoside antibiotics, vancomycin and other ototoxic agents. Since this may lead to permanent damage, these drugs must only be used with furosemide if there are compelling medical reasons.

Anticoagulants: Reduced anticoagulant effect when furosemide used concomitantly with warfarin.

Antidepressants: Increased risk of postural hypotension with tricyclic antidepressants. Enhanced hypotensive effect with monoamine oxidase inhibitors (MAOIs). Increase risk of hypokalaemia when furosemide and reboxetine are used concomitantly.

Antidiabetics: The hypoglycaemic effect is antagonised by loop diuretics.

Antiepileptics: Increased risk of hyponatraemia with concomitant carbamazepine. The diuretic effect of furosemide has been shown to be substantially reduced by concomitant phenytoin therapy.

Antifungals: Increased risk of hypokalaemia with loop diuretics and amphotericin.

Anti-gout: Probenecid has been shown to reduce the renal clearance of furosemide and may increase, decrease or have no effect on the overall diuresis. Furosemide may reduce the renal clearance of probenecid. In case of high-dose treatment (with furosemide and probenecid), this may lead to increased serum levels and an increased risk of adverse effects.

Antihistamines: Hypokalaemia increases risk of ventricular arrhythmias with terfenadine.

Antihypertensives: Furosemide enhances the hypotensive action of other antihypertensive drugs, including beta-blockers, calcium-channel blockers and hydralazine. The dosage of currently administered antihypertensive agents may require adjustment. There is an increase risk of first- dose hypotension with alpha blockers such as prazosin or angiotensin-converting enzyme (ACE) inhibitors such as captopril. Particular care should be taken with ACE inhibitors and angiotensin-II antagonists when initiating or increasing their dose in concomitant therapy with furosemide, since combination can result in marked reduction in blood pressure and deterioration in renal function.
The dose of furosemide should be reduced for at least three days, or the drug stopped, before initiating or increasing the dose of an ACE inhibitor or angiotensin II receptor antagonist. Long term intensive treatment with captopril can enhance the natriuretic response to furosemide.

Antipsychotics: Hypokalaemia increases risk of ventricular arrhythmias with primozide and sertindole, concurrent use should be avoided. Enhanced hypotensive effect with phenothiazines.
Risperidone: Caution should be exercised and the risks and benefits of the combination or co- treatment with furosemide or with other potent diuretics should be considered prior to the decision to use. See section 4.4 Special warnings and precautions for use regarding increased mortality in elderly patients with dementia concomitantly receiving risperidone.

Anxiolytics and hypnotics: Administration of chloral hydrate followed by intravenous furosemide may result in a syndrome of hot flushes, sweating, tachycardia and hypertension.
Cardiac Glycosides: Increased risk of toxicity if hypokalaemia or hypomagnesaemia occurs. The cardiac glycoside dosage may require adjustment as a more pronounced fall in blood pressure must be anticipated if given concomitantly with furosemide.

Corticosteroids: The increased risk of hypokalaemia occurs particularly with the naturally occurring corticosteroids such as cortisone and hydrocortisone. The synthetic corticosteroids have a much less marked potassium-losing effect. Fluid retention associated with corticosteroid use may cause antagonism of diuretic/antihypertensive effect. Concomitant administration of corticosteroids may cause sodium retention.

Cytotoxics: There is a risk of ototoxic effects if cisplatin and furosemide are given concomitantly. In addition, nephrotoxicity of cisplatin may be enhanced if furosemide is not given in low doses (e.g.
40mg in patients with normal renal function) and with positive fluid balance when used to achieve forced dieresis during cisplatin treatment.


Diuretics: Increased risk of hypokalaemia with other loop diuretics and other diuretics, including acetazolamide and thiazides. Severe electrolyte disturbances may occur in patients given metolazone concurrently with furosemide. The dosage of concurrently administered diuretics may require adjustment as a more pronounced fall in blood pressure must be anticipated if given concomitantly with furosemide

Dompaminergics: Enhanced hypotensive effect with levodopa.

Immunosuppressants: Ciclosporin: concomitant use of ciclosporin and furosemide is associated with increased risk of gouty arthritis.

Laxatives: Prolonged use may increase the risk of developing hypokalaemia.

Lithium: In common with other diuretics, serum lithium levels may be increased when lithium is given concomitantly with furosemide, resulting in increased lithium toxicity, including increased risk of cardiotoxic and neurotoxic effects. It is recommended that lithium levels are carefully monitored and where necessary the lithium dosage is adjusted in patients receiving this combination.

Muscle relaxants: Enhanced hypotensive effect may occur with tizanidine; effects of curare-type muscle relaxants may be potentiated.

Nicotine: Nicotine inhibits diuresis and diminishes the diuretic effect of furosemide.

Nitrates: Enhanced hypotensive effect.
Non-steroidal anti-inflammatory agents (NSAIDs): Certain non-steroidal anti-inflammatory agents (e.g. indometacin, ketorolac, acetylsalicylic acid) may attenuate the diuretic effect of furosemide and may cause acute renal failure in cases of pre-existing hypovolaemia or dehydration. Enhanced salicylate toxicity or nephrotoxicity of NSAIDs.

Prostaglandins: Hypotensive effect may be potentiated by alprostadil.

Sympathomimetics: There is an increased risk of hypokalaemia with high doses of β2- sympathomimetics. Effects of pressor amines may be attenuated.

Theophylline: Risk of hypokalaemia may be increased; effects of theophylline may be potentiated.

Ulcer healing drugs: carbenoxolone and liquorice may increase risk of hypokalaemia. Fluid retention associated with carbenoxolone may cause antagonism of diuretic/antihypertensive effect.
Ranitidine causes a moderate increase in the bioavailability of furosemide.