BNF for Children 2011-2012

680 Appendix 1: Interactions BNFC 2011–2012Appendix 1: InteractionsCapreomycinAntibacterials (continued)ototoxicity when capreomycin given withaminoglycosides or vancomycinCytotoxics: increased risk of nephrotoxicity and ototoxicitywhen capreomycin given with platinumcompoundsVaccines: antibacterials inactivate oral typhoidvaccine—see p. 620Captopril see ACE InhibitorsCarbamazepineAlcohol: CNS side-effects of carbamazepine possiblyincreased by alcohol. Analgesics: effects of carbamazepine enhanced by.dextropropoxyphene; carbamazepine reducesplasma concentration of methadone; carbamazepinereduces effects of tramadol; carbamazepine possiblyaccelerates metabolism of paracetamol. Anti-arrhythmics: carbamazepine possibly reducesplasma concentration of .dronedarone—avoid concomitantuse. Antibacterials: plasma concentration of carbamazepineincreased by .clarithromycin and.erythromycin; plasma concentration of carbamazepinereduced by .rifabutin; carbamazepine acceleratesmetabolism of doxycycline (reduced effect);plasma concentration of carbamazepine increased by.isoniazid (also possibly increased isoniazid hepatotoxicity);carbamazepine reduces plasma concentrationof .telithromycin (avoid during and for 2 weeksafter carbamazepine). Anticoagulants: carbamazepine accelerates metabolismof .coumarins (reduced anticoagulant effect). Antidepressants: plasma concentration of carbamazepineincreased by .fluoxetine and .fluvoxamine;carbamazepine reduces plasma concentration of.mianserin and mirtazapine; anticonvulsant effect ofantiepileptics possibly antagonised by MAOIs and.tricyclic-related antidepressants (convulsive thresholdlowered); manufacturer of carbamazepine advisesavoid for 2 weeks after stopping .MAOIs, alsoantagonism of anticonvulsant effect; anticonvulsanteffect of antiepileptics antagonised by .SSRIs and.tricyclics (convulsive threshold lowered); avoidconcomitant use of antiepileptics with .St John’swort; carbamazepine accelerates metabolism of.tricyclics (reduced plasma concentration andreduced effect). Antiepileptics: plasma concentration of both drugsreduced when carbamazepine given with eslicarbazepine;carbamazepine possibly reduces plasmaconcentration of ethosuximide; carbamazepine oftenreduces plasma concentration of lamotrigine, alsoplasma concentration of an active metabolite ofcarbamazepine sometimes raised (but evidence isconflicting); possible increased risk of carbamazepinetoxicity when given with levetiracetam; plasmaconcentration of carbamazepine sometimes reducedby oxcarbazepine (but concentration of an activemetabolite of carbamazepine may be increased), alsoplasma concentration of an active metabolite ofoxcarbazepine often reduced; carbamazepine possiblyincreases plasma concentration of phenobarbital;plasma concentration of both drugs often reducedwhen carbamazepine given with phenytoin, alsoplasma concentration of phenytoin may be increased;plasma concentration of both drugs possibly reducedwhen carbamazepine given with rufinamide; plasmaconcentration of carbamazepine increased by.stiripentol; carbamazepine reduces plasma concentrationof tiagabine and zonisamide; carbamazepineoften reduces plasma concentration of topiramate;carbamazepine reduces plasma concentration ofvalproate, also plasma concentration of activemetabolite of carbamazepine increased. Antifungals: plasma concentration of carbamazepinepossibly increased by fluconazole, ketoconazole andmiconazole; carbamazepine possibly reduces plasmaCarbamazepine. Antifungals (continued)concentration of itraconazole and .posaconazole;carbamazepine possibly reduces plasma concentrationof .voriconazole—avoid concomitant use;carbamazepine possibly reduces plasma concentrationof caspofungin—consider increasing doseof caspofungin. Antimalarials: possible increased risk of convulsionswhen antiepileptics given with chloroquine andhydroxychloroquine; anticonvulsant effect of antiepilepticsantagonised by .mefloquine. Antipsychotics: anticonvulsant effect of antiepilepticsantagonised by .antipsychotics (convulsive thresholdlowered); carbamazepine accelerates metabolism ofhaloperidol, olanzapine, quetiapine and risperidone(reduced plasma concentration); carbamazepinereduces plasma concentration of .aripiprazole—increase dose of aripiprazole; carbamazepine acceleratesmetabolism of .clozapine (reduced plasmaconcentration), also avoid concomitant use of drugswith substantial potential for causing agranulocytosis;carbamazepine reduces plasma concentration ofpaliperidone. Antivirals: carbamazepine possibly reduces plasmaconcentration of darunavir, fosamprenavir, lopinavir,nelfinavir, saquinavir and tipranavir; plasma concentrationof both drugs reduced when carbamazepinegiven with efavirenz; avoidance of carbamazepineadvised by manufacturer of etravirine; carbamazepinepossibly reduces plasma concentration of.indinavir, also plasma concentration of carbamazepinepossibly increased; carbamazepine reducesplasma concentration of nevirapine; plasma concentrationof carbamazepine possibly increased by.ritonavirAnxiolytics and Hypnotics: carbamazepine oftenreduces plasma concentration of clonazepam;carbamazepine reduces plasma concentration ofmidazolamAprepitant: carbamazepine possibly reduces plasmaconcentration of aprepitantBupropion: carbamazepine reduces plasma concentrationof bupropion. Calcium-channel Blockers: carbamazepine reduceseffects of felodipine and isradipine; carbamazepineprobably reduces effects of dihydropyridines,nicardipine and nifedipine; avoidance of carbamazepineadvised by manufacturer of nimodipine (plasmaconcentration of nimodipine possibly reduced);effects of carbamazepine enhanced by .diltiazem and.verapamil. Ciclosporin: carbamazepine accelerates metabolism of.ciclosporin (reduced plasma concentration). Clopidogrel: carbamazepine possibly reduces antiplateleteffect of .clopidogrel. Corticosteroids: carbamazepine accelerates metabolismof .corticosteroids (reduced effect). Cytotoxics: avoidance of carbamazepine advised bymanufacturer of gefitinib; carbamazepine reducesplasma concentration of .imatinib and .lapatinib—avoid concomitant use; carbamazepine reducesplasma concentration of irinotecan and its activemetabolite. Diuretics: increased risk of hyponatraemia whencarbamazepine given with diuretics; plasma concentrationof carbamazepine increased by.acetazolamide; carbamazepine reduces plasmaconcentration of .eplerenone—avoid concomitantuse. Hormone Antagonists: metabolism of carbamazepineinhibited by .danazol (increased risk of toxicity);carbamazepine possibly accelerates metabolism oftoremifene (reduced plasma concentration)5HT 3 Antagonists: carbamazepine accelerates metabolismof ondansetron (reduced effect)