BNF for Children 2011-2012

690 Appendix 1: Interactions BNFC 2011–2012Appendix 1: InteractionsDisopyramide (continued). Diuretics: increased cardiac toxicity with disopyramideif hypokalaemia occurs with .acetazolamide, .loopdiuretics or .thiazides and related diuretics. Ivabradine: increased risk of ventricular arrhythmiaswhen disopyramide given with .ivabradineNitrates: disopyramide reduces effects of sublingualtablets of nitrates (failure to dissolve under tongueowing to dry mouth). Ranolazine: avoidance of disopyramide advised bymanufacturer of .ranolazineDistigmine see ParasympathomimeticsDisulfiramAlcohol: disulfiram reaction when disulfiram given withalcohol (see BNF section 4.10.1)Antibacterials: psychotic reaction reported whendisulfiram given with metronidazole; CNS effects ofdisulfiram possibly increased by isoniazid. Anticoagulants: disulfiram enhances anticoagulanteffect of .coumarinsAntidepressants: increased disulfiram reaction withalcohol reported with concomitant amitriptyline;disulfiram inhibits metabolism of tricyclics (increasedplasma concentration). Antiepileptics: disulfiram inhibits metabolism of.phenytoin (increased risk of toxicity)Anxiolytics and Hypnotics: disulfiram increases risk oftemazepam toxicity; disulfiram inhibits metabolism ofbenzodiazepines (increased sedative effects). Paraldehyde: risk of toxicity when disulfiram givenwith .paraldehydeTheophylline: disulfiram inhibits metabolism of theophylline(increased risk of toxicity)DiureticsNote Since systemic absorption may follow topical applicationof brinzolamide to the eye, the possibility of interactionsshould be borne in mindNote Since systemic absorption may follow topical applicationof dorzolamide to the eye, the possibility of interactionsshould be borne in mind. ACE Inhibitors: enhanced hypotensive effect whendiuretics given with .ACE inhibitors; increased risk ofsevere hyperkalaemia when potassium-sparing diureticsand aldosterone antagonists given with .ACEinhibitors (monitor potassium concentration withlow-dose spironolactone in heart failure)Adrenergic Neurone Blockers: enhanced hypotensiveeffect when diuretics given with adrenergic neuroneblockersAlcohol: enhanced hypotensive effect when diureticsgiven with alcoholAldesleukin: enhanced hypotensive effect when diureticsgiven with aldesleukinAliskiren: plasma concentration of furosemide reducedby aliskiren; increased risk of hyperkalaemia whenpotassium-sparing diuretics and aldosterone antagonistsgiven with aliskirenAllopurinol: increased risk of hypersensitivity whenthiazides and related diuretics given with allopurinolespecially in renal impairment. Alpha-blockers: enhanced hypotensive effect whendiuretics given with .alpha-blockers, also increasedrisk of first-dose hypotension with post-synapticalpha-blockers such as prazosinAnaesthetics, General: enhanced hypotensive effectwhen diuretics given with general anaesthetics. Analgesics: diuretics increase risk of nephrotoxicity ofNSAIDs, also antagonism of diuretic effect; Diureticeffect of potassium canrenoate possibly antagonisedby NSAIDs; possible increased risk of hyperkalaemiawhen potassium-sparing diuretics and aldosteroneantagonists given with NSAIDs; effects of diureticsantagonised by indometacin and ketorolac; increasedrisk of hyperkalaemia when potassium-sparing diureticsand aldosterone antagonists given with indometacin;occasional reports of reduced renal functionwhen triamterene given with .indometacin—avoidconcomitant use; diuretic effect of spironolactoneantagonised by aspirin; increased risk of toxicityDiuretics. Analgesics (continued)when carbonic anhydrase inhibitors given withhigh-dose aspirin. Angiotensin-II Receptor Antagonists: enhancedhypotensive effect when diuretics given with.angiotensin-II receptor antagonists; increased risk ofhyperkalaemia when potassium-sparing diuretics andaldosterone antagonists given with .angiotensin-IIreceptor antagonists. Anti-arrhythmics: plasma concentration of eplerenoneincreased by amiodarone (reduce dose of eplerenone);hypokalaemia caused by acetazolamide, loopdiuretics or thiazides and related diuretics increasescardiac toxicity with amiodarone; hypokalaemiacaused by acetazolamide, loop diuretics or thiazidesand related diuretics increases cardiac toxicity with.disopyramide; hypokalaemia caused by acetazolamide,loop diuretics or thiazides and related diureticsincreases cardiac toxicity with .flecainide;hypokalaemia caused by acetazolamide, loopdiuretics or thiazides and related diuretics antagonisesaction of .lidocaine. Antibacterials: plasma concentration of eplerenoneincreased by .clarithromycin and .telithromycin—avoid concomitant use; plasma concentration ofeplerenone increased by erythromycin (reduce doseof eplerenone); plasma concentration of eplerenonereduced by .rifampicin—avoid concomitant use;avoidance of diuretics advised by manufacturer oflymecycline; increased risk of otoxicity when loopdiuretics given with .aminoglycosides,.polymyxins or .vancomycin; acetazolamide antagoniseseffects of .methenamine; increased risk ofhyperkalaemia when eplerenone given with trimethoprim. Antidepressants: possible increased risk of hypokalaemiawhen loop diuretics or thiazides and relateddiuretics given with reboxetine; enhanced hypotensiveeffect when diuretics given with MAOIs; plasmaconcentration of eplerenone reduced by .St John’swort—avoid concomitant use; increased risk ofpostural hypotension when diuretics given withtricyclicsAntidiabetics: loop diuretics and thiazides and relateddiuretics antagonise hypoglycaemic effect of antidiabetics. Antiepileptics: plasma concentration of eplerenonereduced by .carbamazepine, .phenobarbital and.phenytoin—avoid concomitant use; increased riskof hyponatraemia when diuretics given with carbamazepine;acetazolamide increases plasma concentrationof .carbamazepine; increased risk ofosteomalacia when carbonic anhydrase inhibitorsgiven with phenobarbital or phenytoin; effects offurosemide antagonised by phenytoin; acetazolamidepossibly increases plasma concentration of.phenytoin; hydrochlorothiazide possibly increasesplasma concentration of topiramate. Antifungals: plasma concentration of eplerenoneincreased by .itraconazole and .ketoconazole—avoid concomitant use; increased risk of hypokalaemiawhen loop diuretics or thiazides and relateddiuretics given with amphotericin; hydrochlorothiazideincreases plasma concentration of fluconazole;plasma concentration of eplerenone increasedby fluconazole (reduce dose of eplerenone). Antipsychotics: hypokalaemia caused by diureticsincreases risk of ventricular arrhythmias with.amisulpride; enhanced hypotensive effect whendiuretics given with phenothiazines; hypokalaemiacaused by diuretics increases risk of ventriculararrhythmias with .pimozide (avoid concomitant use). Antivirals: plasma concentration of eplerenoneincreased by .nelfinavir and .ritonavir—avoid concomitantuse; plasma concentration of eplerenoneincreased by saquinavir (reduce dose of eplerenone)Anxiolytics and Hypnotics: enhanced hypotensiveeffect when diuretics given with anxiolytics and