BNF for Children 2011-2012

BNFC 2011–2012 Appendix 1: Interactions 667Antifungals, Imidazole (continued). Clopidogrel: ketoconazole possibly reduces antiplateleteffect of .clopidogrel. Colchicine: ketoconazole possibly increases risk of.colchicine toxicity—suspend or reduce dose ofcolchicine (avoid concomitant use in hepatic or renalimpairment)Corticosteroids: ketoconazole possibly inhibits metabolismof corticosteroids; ketoconazole increasesplasma concentration of inhaled and oral budesonide;ketoconazole increases plasma concentration ofactive metabolite of ciclesonide; ketoconazole inhibitsthe metabolism of methylprednisolone; ketoconazoleincreases plasma concentration of inhaledmometasone. Cytotoxics: ketoconazole possibly increases plasmaconcentration of dasatinib; ketoconazole inhibitsmetabolism of erlotinib and sunitinib (increasedplasma concentration); ketoconazole increasesplasma concentration of .everolimus, .lapatinib and.nilotinib—avoid concomitant use; ketoconazoleincreases plasma concentration of bortezomib andimatinib; avoidance of ketoconazole advised bymanufacturer of .pazopanib; ketoconazole increasesplasma concentration of active metabolite of.temsirolimus—avoid concomitant use; in vitrostudies suggest a possible interaction between ketoconazoleand docetaxel (consult docetaxel productliterature); ketoconazole reduces plasma concentrationof .irinotecan (but concentration of activemetabolite of irinotecan increased)—avoid concomitantuse; ketoconazole increases plasma concentrationof .vinflunine—manufacturer of vinflunineadvises avoid concomitant use. Diuretics: ketoconazole increases plasma concentrationof .eplerenone—avoid concomitant use. Domperidone: ketoconazole possibly increases risk ofarrhythmias with .domperidone. Ergot Alkaloids: increased risk of ergotism whenimidazoles given with .ergotamine and methysergide—avoidconcomitant use. 5HT 1 Agonists: ketoconazole increases plasma concentrationof almotriptan (increased risk of toxicity);ketoconazole increases plasma concentration of.eletriptan (risk of toxicity)—avoid concomitant use. Ivabradine: ketoconazole increases plasma concentrationof .ivabradine—avoid concomitant useLanthanum: absorption of ketoconazole possiblyreduced by lanthanum (give at least 2 hours apart). Lipid-regulating Drugs: possible increased risk ofmyopathy when imidazoles given with atorvastatin;increased risk of myopathy when ketoconazole givenwith .simvastatin (avoid concomitant use); possibleincreased risk of myopathy when miconazole givenwith .simvastatin—avoid concomitant useOestrogens: anecdotal reports of contraceptive failurewhen imidazoles given with oestrogensParasympathomimetics: ketoconazole increasesplasma concentration of galantamine. Ranolazine: ketoconazole increases plasma concentrationof .ranolazine—avoid concomitant useRetinoids: ketoconazole increases plasma concentrationof alitretinoinSildenafil: ketoconazole increases plasma concentrationof sildenafil—reduce initial dose of sildenafil. Sirolimus: ketoconazole increases plasma concentrationof .sirolimus—avoid concomitant use; miconazoleincreases plasma concentration of .sirolimusSympathomimetics, Beta 2 : ketoconazole inhibitsmetabolism of salmeterol (increased plasma concentration). Tacrolimus: imidazoles possibly increase plasma concentrationof .tacrolimus; ketoconazole increasesplasma concentration of .tacrolimus (consider reducingdose of tacrolimus). Tadalafil: ketoconazole increases plasma concentrationof .tadalafil—manufacturer of tadalafil advises avoidconcomitant useAntifungals, Imidazole (continued). Theophylline: ketoconazole possibly increases plasmaconcentration of .theophyllineTolvaptan: ketoconazole increases plasma concentrationof tolvaptanUlcer-healing Drugs: absorption of ketoconazolereduced by histamine H 2 -antagonists, proton pumpinhibitors and sucralfate. Vardenafil: ketoconazole increases plasma concentrationof .vardenafil—avoid concomitant useVitamins: ketoconazole possibly increases plasmaconcentration of paricalcitolAntifungals, Polyene see AmphotericinAntifungals, TriazoleNote In general, fluconazole interactions relate to multipledosetreatment. Analgesics: fluconazole increases plasma concentrationof celecoxib (halve dose of celecoxib); voriconazoleincreases plasma concentration of diclofenac,ibuprofen and .oxycodone; fluconazole increasesplasma concentration of flurbiprofen and ibuprofen;fluconazole increases plasma concentration of parecoxib(reduce dose of parecoxib); voriconazoleincreases plasma concentration of .alfentanil and.methadone (consider reducing dose ofalfentanil and methadone); fluconazole inhibitsmetabolism of alfentanil (risk of prolonged or delayedrespiratory depression); itraconazole possibly inhibitsmetabolism of alfentanil; triazoles possibly increaseplasma concentration of .fentanylAntacids: absorption of itraconazole reduced byantacids. Anti-arrhythmics: manufacturer of itraconazole advisesavoid concomitant use with .disopyramide; avoidanceof itraconazole, posaconazole and voriconazoleadvised by manufacturer of .dronedarone. Antibacterials: plasma concentration of itraconazoleincreased by clarithromycin; triazoles possiblyincrease plasma concentration of .rifabutin(increased risk of uveitis—reduce rifabutin dose);posaconazole increases plasma concentration of.rifabutin (also plasma concentration of posaconazolereduced); voriconazole increases plasma concentrationof .rifabutin, also rifabutin reduces plasmaconcentration of voriconazole (increase dose ofvoriconazole and also monitor for rifabutin toxicity);fluconazole increases plasma concentration of.rifabutin (increased risk of uveitis—reduce rifabutindose); plasma concentration of itraconazole reducedby .rifabutin and .rifampicin—manufacturer of itraconazoleadvises avoid concomitant use; plasmaconcentration of posaconazole reduced by.rifampicin; plasma concentration of voriconazolereduced by .rifampicin—avoid concomitant use;metabolism of fluconazole accelerated by .rifampicin(reduced plasma concentration). Anticoagulants: fluconazole, itraconazole and voriconazoleenhance anticoagulant effect of .coumarins;avoidance of itraconazole, posaconazole and voriconazoleadvised by manufacturer of rivaroxaban. Antidepressants: avoidance of triazoles advised bymanufacturer of .reboxetine; plasma concentrationof voriconazole reduced by .St John’s wort—avoidconcomitant use. Antidiabetics: posaconazole possibly enhances hypoglycaemiceffect of glipizide; fluconazole possiblyenhances hypoglycaemic effect of nateglinide; itraconazolepossibly enhances hypoglycaemic effect ofrepaglinide; fluconazole increases plasma concentrationof .sulfonylureas; voriconazole possiblyincreases plasma concentration of sulfonylureas. Antiepileptics: fluconazole possibly increases plasmaconcentration of carbamazepine; plasma concentrationof voriconazole possibly reduced by.carbamazepine and .phenobarbital—avoid concomitantuse; plasma concentration of itraconazole andposaconazole possibly reduced by .carbamazepine;plasma concentration of itraconazole and posaconazolepossibly reduced by .phenobarbital; fluconazoleAppendix 1: Interactions