BNF for Children 2011-2012

BNFC 2011–2012 Appendix 1: Interactions 687Coumarins (continued)Aprepitant: anticoagulant effect of warfarin possiblyreduced by aprepitant. Azathioprine: anticoagulant effect of coumarins possiblyreduced by .azathioprineBosentan: monitoring anticoagulant effect of coumarinsrecommended by manufacturer of bosentan. Clopidogrel: anticoagulant effect of coumarinsenhanced due to antiplatelet action of .clopidogrel;avoidance of warfarin advised by manufacturer of.clopidogrel. Corticosteroids: anticoagulant effect of coumarins maybe enhanced or reduced by .corticosteroids (highdosecorticosteroids enhance anticoagulant effect). Cranberry Juice: anticoagulant effect of coumarinspossibly enhanced by .cranberry juice—avoid concomitantuse. Cytotoxics: anticoagulant effect of coumarins possiblyenhanced by .etoposide, .ifosfamide and .sorafenib;anticoagulant effect of coumarins enhanced by.fluorouracil; anticoagulant effect of warfarin possiblyenhanced by .gefitinib and gemcitabine; anticoagulanteffect of coumarins possibly reduced by.mercaptopurine and .mitotane; increased risk ofbleeding when coumarins given with .erlotinib;replacement of warfarin with a heparin advised bymanufacturer of imatinib (possibility of enhancedwarfarin effect). Dipyridamole: anticoagulant effect of coumarinsenhanced due to antiplatelet action of .dipyridamole. Disulfiram: anticoagulant effect of coumarinsenhanced by .disulfiram. Dopaminergics: anticoagulant effect of warfarinenhanced by .entacapone. Enteral Foods: anticoagulant effect of coumarinsantagonised by vitamin K (present in some .enteralfeeds ). Glucosamine: anticoagulant effect of warfarinenhanced by .glucosamine (avoid concomitant use). Hormone Antagonists: anticoagulant effect of coumarinspossibly enhanced by bicalutamide and.toremifene; metabolism of coumarins inhibited by.danazol (enhanced anticoagulant effect); anticoagulanteffect of coumarins enhanced by.flutamide and .tamoxifenIloprost: anticoagulant effect of coumarins possiblyenhanced by iloprostLactulose: anticoagulant effect of coumarins possiblyenhanced by lactuloseLeflunomide: anticoagulant effect of warfarin possiblyenhanced by leflunomideLeukotriene Receptor Antagonists: anticoagulanteffect of warfarin enhanced by zafirlukast. Levamisole: anticoagulant effect of warfarin possiblyenhanced by .levamisole. Lipid-regulating Drugs: anticoagulant effect of coumarinsmay be enhanced or reduced by.colestyramine; anticoagulant effect of warfarin maybe transiently reduced by atorvastatin; anticoagulanteffect of coumarins enhanced by .fibrates,.fluvastatin and simvastatin; anticoagulant effect ofcoumarins possibly enhanced by ezetimibe and.rosuvastatinMemantine: anticoagulant effect of warfarin possiblyenhanced by memantineOestrogens: anticoagulant effect of coumarins may beenhanced or reduced by oestrogensOrlistat: monitoring anticoagulant effect of coumarinsrecommended by manufacturer of orlistatPrasugrel: possible increased risk of bleeding whencoumarins given with prasugrelProgestogens: anticoagulant effect of coumarins maybe enhanced or reduced by progestogensRaloxifene: anticoagulant effect of coumarins antagonisedby raloxifene. Retinoids: anticoagulant effect of coumarins possiblyreduced by .acitretin. Sitaxentan: anticoagulant effect of coumarinsenhanced by .sitaxentanCoumarins (continued). Sulfinpyrazone: anticoagulant effect of coumarinsenhanced by .sulfinpyrazone. Sympathomimetics: anticoagulant effect of coumarinspossibly enhanced by .methylphenidate. Testolactone: anticoagulant effect of coumarinsenhanced by .testolactone. Testosterone: anticoagulant effect of coumarinsenhanced by .testosterone. Thyroid Hormones: anticoagulant effect of coumarinsenhanced by .thyroid hormonesUbidecarenone: anticoagulant effect of warfarin maybe enhanced or reduced by ubidecarenone. Ulcer-healing Drugs: metabolism of coumarins inhibitedby .cimetidine (enhanced anticoagulant effect);anticoagulant effect of coumarins possibly enhancedby .esomeprazole, .omeprazole and pantoprazole;absorption of coumarins possibly reduced by.sucralfate (reduced anticoagulant effect)Vaccines: anticoagulant effect of warfarin possiblyenhanced by influenza vaccine. Vitamins: anticoagulant effect of coumarins possiblyenhanced by .vitamin E; anticoagulant effect ofcoumarins antagonised by .vitamin KCranberry Juice. Anticoagulants: cranberry juice possibly enhancesanticoagulant effect of .coumarins—avoid concomitantuseCyclizine see AntihistaminesCyclopenthiazide see DiureticsCyclopentolate see AntimuscarinicsCyclophosphamideAntifungals: side-effects of cyclophosphamide possiblyincreased by itraconazole. Antipsychotics: avoid concomitant use of cytotoxicswith .clozapine (increased risk of agranulocytosis)Cardiac Glycosides: cyclophosphamide possiblyreduces absorption of digoxin tablets. Cytotoxics: increased toxicity when high-dose cyclophosphamidegiven with .pentostatin—avoid concomitantuseMuscle Relaxants: cyclophosphamide enhanceseffects of suxamethoniumCycloserine. Alcohol: increased risk of convulsions when cycloserinegiven with .alcoholAntibacterials: increased risk of CNS toxicity whencycloserine given with isoniazidVaccines: antibacterials inactivate oral typhoidvaccine—see p. 620Cyproheptadine see AntihistaminesCytarabineAntifungals: cytarabine possibly reduces plasma concentrationof flucytosine. Antipsychotics: avoid concomitant use of cytotoxicswith .clozapine (increased risk of agranulocytosis)Cardiac Glycosides: cytarabine possibly reducesabsorption of digoxin tabletsCytotoxics: intracellular concentration of cytarabineincreased by fludarabineCytotoxics see individual drugsDabigatran Etexilate. Analgesics: possible increased risk of bleeding whendabigatran etexilate given with .NSAIDs; increasedrisk of haemorrhage when anticoagulants given withintravenous .diclofenac (avoid concomitant use,including low-dose heparins); increased risk ofhaemorrhage when anticoagulants given with.ketorolac (avoid concomitant use, including lowdoseheparins). Anti-arrhythmics: plasma concentration of dabigatranetexilate increased by .amiodarone (reduce dose ofdabigatran etexilate). Calcium-channel Blockers: plasma concentration ofdabigatran etexilate possibly increased by .verapamil(reduce dose of dabigatran etexilate)Appendix 1: Interactions