Interactions : אינטראקציות

4.5. Interaction with other medicinal products and other forms of interaction
• ACE Inhibitors - enhanced hypotensive effect when given with diuretics. A marked falls in blood pressure and deterioration in renal function may be seen when ACE inhibitors are added to furosemide therapy. The dose of furosemide should be reduced for at least three days, or the drug stopped, before initiating the ACE inhibitor or increasing the dose of an ACE inhibitor.
• Alpha-blockers - enhanced hypotensive effect when diuretics are given with alpha- blockers, also increased risk of a first-dose hypotension with post-synaptic alpha blockers such as prazosin.
• Beta-blockers - there is an enhanced hypotensive effect when diuretics are given with beta- blockers. Hypokalaemia caused by loop diuretics increases the risk of ventricular arrhythmias with sotalol.
• Angiotensin-II Receptor Antagonists - enhanced hypotensive effect when diuretics given with angiotensin-II receptor antagonists.
• Antipsychotics - hypokalaemia caused by diuretics increase the risk of ventricular arrhythmias with amisulpride or sertindole. An enhanced hypotensive effect may be seen when diuretics are given with phenothiazines. Hypokalaemia caused by diuretics increases risk of ventricular arrhythmias with pimozide (avoid concomitant use).
• Risperidone - when administering 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. Increased mortality has been observed in elderly patients with dementia concomitantly receiving risperidone.
• Anti-arrhythmics - hypokalaemia caused by loop diuretics increases cardiac toxicity with amiodarone, disopyramide, flecainide and antagonises the action of lidocaine and mexiletine.
• Cardiac glycosides - hypokalaemia caused by loop diuretics increases cardiac toxicity with cardiac glycosides.
• Other diuretics - there is an increased risk of hypokalaemia when loop diuretics are given with acetazolamide. Profound diuresis is possible when metolazone is given with furosemide.
There is an increased risk of hypokalaemia when loop diuretics are given with thiazides and related diuretics.
• Renin inhibitors - aliskiren reduces plasma concentration of furosemide given orally.
Reduced effect of furosemide might be observed in patients treated with both aliskiren and oral furosemide, and it is recommended to monitor for reduced diuretic effect and adjust the dose accordingly.
• Lithium - loop diuretics reduce the excretion of lithium, which may lead to increased plasma concentrations and a risk of toxicity. Therefore, it is recommended that lithium levels are carefully monitored and where necessary the lithium dosage is adjusted in patients receiving this combination.
• Potassium salts - there is an increased risk of hyperkalaemia when given with potassium salts.
• Sucralfate - furosemide and sucralfate must not be taken within 2 hours of each other as sucralfate decreases the absorption of furosemide from the intestine and so reduces its effect.
• Lipid regulating drugs – Bile acid sequestrants (e.g. colestyramine, colestipol) - reduced absorption of furosemide - administer 2 to 3 hours apart.
• Analgesics - diuretics can increase the risk of nephrotoxicity of NSAIDs, also antagonism of diuretic effect. Antagonism of diuretic effect (especially with indometacin and ketorolac).
Salycylic toxicity may be increased by furosemide.
• Antibacterials - avoid the use of diuretics in lymecycline treatment. There is an increased risk of ototoxicity when loop diuretics are given with aminoglycosides, polymyxins or vancomycin. Since this may lead to irreversible damage, these drugs must only be used with furosemide if there are compelling medical reasons. Impairment of renal function may 
develop in patients receiving concurrent treatment with furosemide and high doses of certain cephalosporins.
•   Ciclosporin - there is an increased risk of nephrotoxicity and possibly hypermagnesaemia when diuretics are given with ciclosporin.
Antidepressants - possible increase of hypokalaemia when loop diuretics are given with reboxetine. There is an enhanced hypotensive effect when diuretics are given with MAOIs.
There is an increased risk of postural hypotension when diuretics are given with tricyclic antidepressants.
•   Antiepileptics - there is an increased risk of hyponatraemia when diuretics are given with carbamazepine. The effects of furosemide are antagonized by phenytoin.
•   Antifungals - there is an increased risk of hypokalaemia when loop diuretics are given with amphoterecin.
•   Antivirals - plasma concentration of diuretics may be increased by nelfinavir, ritonavir or saquinavir.
•   Atomoxetine - hypokalaemia caused by diuretics increases the risk of ventricular arrhythmias with atomoxetine.
•   Barbiturates - plasma concentrations of diuretics may be decreased. There may be an increased risk of osteomalacia when diuretics are taken in combination with Phenobarbital.
•   Corticosteroids - the diuretic effect of diuretics is antagonized by corticosteroids. There is an increased risk of hypokalaemia when loop diuretics are given with corticosteroids.
•   Cisplatin - there is a risk of increased 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 diuresis during cisplatin treatment.
•   Dopaminergics - enhanced hypotensive effect with levodopa.
•   Muscle relaxants - enhanced hypotensive effect with baclofen or tizanidine.
•   Oestrogens and progestogens - diuretic effect antagonized.
•   Prostaglandins - enhanced hypotensive effect with alprostadil.
•   Sympathomimetics, Beta2 - there is an increased risk of hypokalaemia when loop diuretics are given with high doses of beta2 sympathomimetics.
•   Tacrolimus - there is an increased risk of hypokalaemia when given with tacrolimus.
•   Theophylline - there is an increased risk of hypokalaemia when loop diuretics are given with theophylline.
•   Warfarin and clofibrate - warfarin and clofibrate compete with furosemide in the binding to serum albumin. This may have clinical significance in patients with low serum albumin levels (e.g. in nephrotic syndrome). Furosemide does not change the pharmacokinetics of warfarin to a significant extent, but a strong diuresis with associated dehydration may weaken the antithrombotic effect of warfarin.
•   Probenecid, methotrexate and other drugs which, like furosemide, undergo significant renal tubular secretion may reduce the effect of furosemide. Conversely, furosemide may decrease renal elimination of these drugs. In case of high-dose treatment (in particular, of both furosemide and the other drugs), this may lead to increased serum levels and an increased risk of adverse effects due to furosemide or the concomitant medication.
•   Anaesthetic agents – general anaesthetic agents may enhance the hypotensive effects of furosemide. The effects of curare may be enhanced by furosemide.
•   Alcohol – enhanced hypotensive effect.
•   Carbenoxolone, prolonged use of laxatives, liquorice - may increase the risk of developing hypokalaemia.