BNF for Children 2011-2012

674 Appendix 1: Interactions BNFC 2011–2012Appendix 1: InteractionsArsenic Trioxide. Anti-arrhythmics: increased risk of ventricular arrhythmiaswhen arsenic trioxide given with.amiodarone or .disopyramide. Antibacterials: increased risk of ventricular arrhythmiaswhen arsenic trioxide given with .erythromycin,.levofloxacin or .moxifloxacin. Antidepressants: increased risk of ventricular arrhythmiaswhen arsenic trioxide given with.amitriptyline or .clomipramine. Antifungals: increased risk of ventricular arrhythmiaswhen arsenic trioxide given with .amphotericin. Antipsychotics: increased risk of ventricular arrhythmiaswhen arsenic trioxide given with.antipsychotics that prolong the QT interval;increased risk of ventricular arrhythmias whenarsenic trioxide given with .haloperidol; avoid concomitantuse of cytotoxics with .clozapine (increasedrisk of agranulocytosis). Beta-blockers: increased risk of ventricular arrhythmiaswhen arsenic trioxide given with .sotalol. Diuretics: risk of ventricular arrhythmias with arsenictrioxide increased by hypokalaemia caused by.acetazolamide, .loop diuretics or .thiazides andrelated diuretics. Lithium: increased risk of ventricular arrhythmias whenarsenic trioxide given with .lithiumArtemether with Lumefantrine. Anti-arrhythmics: manufacturer of artemether/lumefantrineadvises avoid concomitant use with.amiodarone, .disopyramide or .flecainide (risk ofventricular arrhythmias). Antibacterials: manufacturer of artemether/lumefantrineadvises avoid concomitant use with.macrolides and .quinolones. Antidepressants: manufacturer of artemether/lumefantrineadvises avoid concomitant use with.antidepressants. Antifungals: manufacturer of artemether/lumefantrineadvises avoid concomitant use with .imidazoles and.triazoles. Antimalarials: manufacturer of artemether/lumefantrineadvises avoid concomitant use with.antimalarials; increased risk of ventricular arrhythmiaswhen artemether/lumefantrine given with.quinine. Antipsychotics: manufacturer of artemether/lumefantrineadvises avoid concomitant use with.antipsychoticsAntivirals: manufacturer of artemether/lumefantrineadvises caution with atazanavir, darunavir, fosamprenavir,indinavir, lopinavir, nelfinavir, ritonavir,saquinavir and tipranavir. Beta-blockers: manufacturer of artemether/lumefantrineadvises avoid concomitant use with.metoprolol and .sotalolGrapefruit Juice: plasma concentration of artemether/lumefantrine possibly increased by grapefruit juiceHistamine: avoidance of antimalarials advised bymanufacturer of histamine. Ulcer-healing Drugs: manufacturer of artemether/lumefantrine advises avoid concomitant use with.cimetidineVaccines: antimalarials inactivate oral typhoidvaccine—see p. 620Ascorbic acid see VitaminsAspirinAdsorbents: absorption of aspirin possibly reduced bykaolinAnaesthetics, General: aspirin possibly enhanceseffects of thiopental. Analgesics: avoid concomitant use of aspirin with.NSAIDs (increased side-effects); antiplatelet effectof aspirin possibly reduced by ibuprofenAntacids: excretion of aspirin increased by alkalineurine due to some antacids. Anticoagulants: increased risk of bleeding whenaspirin given with .coumarins or .phenindione (dueAspirin. Anticoagulants (continued)to antiplatelet effect); aspirin enhances anticoagulanteffect of .heparins. Antidepressants: increased risk of bleeding whenaspirin given with .SSRIs or .venlafaxineAntiepileptics: aspirin enhances effects ofphenytoin and valproateClopidogrel: increased risk of bleeding when aspiringiven with clopidogrelCorticosteroids: increased risk of gastro-intestinalbleeding and ulceration when aspirin given withcorticosteroids, also corticosteroids reduce plasmaconcentration of salicylate. Cytotoxics: aspirin reduces excretion of .methotrexate(increased risk of toxicity)Diuretics: aspirin antagonises diuretic effect ofspironolactone; increased risk of toxicity when highdoseaspirin given with carbonic anhydrase inhibitorsIloprost: increased risk of bleeding when aspirin givenwith iloprostLeukotriene Receptor Antagonists: aspirin increasesplasma concentration of zafirlukastMetoclopramide: rate of absorption of aspirinincreased by metoclopramide (enhanced effect)Probenecid: aspirin antagonises effects of probenecidSulfinpyrazone: aspirin antagonises effects of sulfinpyrazoneAtazanavirAntacids: plasma concentration of atazanavir possiblyreduced by antacids. Anti-arrhythmics: atazanavir possibly increases plasmaconcentration of .amiodarone and .lidocaine. Antibacterials: plasma concentration of both drugsincreased when atazanavir given with clarithromycin;atazanavir increases plasma concentration of.rifabutin (reduce dose of rifabutin); plasma concentrationof atazanavir reduced by .rifampicin—avoidconcomitant use; avoidance of concomitant atazanavirin severe renal and hepatic impairment advisedby manufacturer of .telithromycinAnticoagulants: atazanavir may enhance or reduceanticoagulant effect of warfarin; avoidance of atazanaviradvised by manufacturer of rivaroxaban. Antidepressants: plasma concentration of atazanavirreduced by .St John’s wort—avoid concomitant use. Antifungals: plasma concentration of atazanavirincreased by .posaconazole. Antimalarials: caution with atazanavir advised bymanufacturer of artemether/lumefantrine; atazanavirpossibly increases plasma concentration of .quinine(increased risk of toxicity)Antimuscarinics: avoidance of atazanavir advised bymanufacturer of darifenacin; manufacturer of fesoterodineadvises dose reduction when atazanavirgiven with fesoterodine—consult fesoterodineproduct literature. Antipsychotics: atazanavir possibly inhibits metabolismof .aripiprazole (reduce dose of aripiprazole);atazanavir possibly increases plasma concentrationof .pimozide—avoid concomitant use. Antivirals: manufacturer of atazanavir advises avoidconcomitant use with .efavirenz (plasma concentrationof atazanavir reduced); avoid concomitant use ofatazanavir with .indinavir; atazanavir increasesplasma concentration of .maraviroc (consider reducingdose of maraviroc); plasma concentration ofatazanavir possibly reduced by .nevirapine—avoidconcomitant use; increased risk of ventricular arrhythmiaswhen atazanavir given with .saquinavir—avoid concomitant use; plasma concentration ofatazanavir reduced by tenofovir, also plasma concentrationof tenofovir possibly increased; atazanavirincreases plasma concentration of tipranavir (alsoplasma concentration of atazanavir reduced). Anxiolytics and Hypnotics: atazanavir possiblyincreases plasma concentration of .midazolam—avoid concomitant use of oral midazolam