BNF for Children 2011-2012

702 Appendix 1: Interactions BNFC 2011–2012Appendix 1: InteractionsLanreotideAntidiabetics: lanreotide possibly reduces requirementsfor insulin, metformin, repaglinide and sulfonylureasCiclosporin: lanreotide reduces plasma concentrationof ciclosporinLansoprazole see Proton Pump InhibitorsLanthanumAntibacterials: lanthanum possibly reduces absorptionof quinolones (give at least 2 hours before or 4 hoursafter lanthanum)Antifungals: lanthanum possibly reduces absorption ofketoconazole (give at least 2 hours apart)Antimalarials: lanthanum possibly reduces absorptionof chloroquine and hydroxychloroquine (give at least2 hours apart)Thyroid Hormones: lanthanum reduces absorption oflevothyroxine (give at least 2 hours apart)Lapatinib. Antibacterials: manufacturer of lapatinib advises avoidconcomitant use with .rifabutin, .rifampicin and.telithromycin. Antidepressants: manufacturer of lapatinib advisesavoid concomitant use with .St John’s wort. Antidiabetics: manufacturer of lapatinib advises avoidconcomitant use with .repaglinide. Antiepileptics: plasma concentration of lapatinibreduced by .carbamazepine—avoid concomitantuse; manufacturer of lapatinib advises avoid concomitantuse with .phenytoin. Antifungals: plasma concentration of lapatinibincreased by .ketoconazole—avoid concomitant use;manufacturer of lapatinib advises avoid concomitantuse with .itraconazole, .posaconazole and.voriconazole. Antipsychotics: avoid concomitant use of cytotoxicswith .clozapine (increased risk of agranulocytosis);manufacturer of lapatinib advises avoid concomitantuse with .pimozide. Antivirals: manufacturer of lapatinib advises avoidconcomitant use with .ritonavir and .saquinavir. Cytotoxics: lapatinib increases plasma concentration ofpazopanib; possible increased risk of neutropeniawhen lapatinib given with docetaxel; increased risk ofneutropenia when lapatinib given with .paclitaxel;lapatinib increases plasma concentration of activemetabolite of .irinotecan—consider reducing dose ofirinotecan. Grapefruit Juice: manufacturer of lapatinib advisesavoid concomitant use with .grapefruit juiceUlcer-healing Drugs: absorption of lapatinib possiblyreduced by histamine H 2 -antagonists and protonpump inhibitorsLaronidaseAntimalarials: effects of laronidase possibly inhibitedby chloroquine and hydroxychloroquine (manufacturerof laronidase advises avoid concomitant use)LeflunomideNote Increased risk of toxicity with other haematotoxic andhepatotoxic drugsAntibacterials: plasma concentration of active metaboliteof leflunomide possibly increased by rifampicinAnticoagulants: leflunomide possibly enhances anticoagulanteffect of warfarinAntidiabetics: leflunomide possibly enhances hypoglycaemiceffect of tolbutamideAntiepileptics: leflunomide possibly increases plasmaconcentration of phenytoin. Cytotoxics: risk of toxicity when leflunomide given with.methotrexateLipid-regulating Drugs: the effect of leflunomide issignificantly decreased by colestyramine (enhancedelimination)—avoid unless drug elimination desired. Vaccines: avoid concomitant use of leflunomide withlive .vaccines (see p. 599)LenalidomideCardiac Glycosides: lenalidomide possibly increasesplasma concentration of digoxinLercanidipine see Calcium-channel BlockersLeukotriene Receptor AntagonistsAnalgesics: plasma concentration of zafirlukastincreased by aspirinAntibacterials: plasma concentration of zafirlukastreduced by erythromycinAnticoagulants: zafirlukast enhances anticoagulanteffect of warfarinAntiepileptics: plasma concentration of montelukastreduced by phenobarbitalTheophylline: zafirlukast possibly increases plasmaconcentration of theophylline, also plasma concentrationof zafirlukast reducedLevamisoleAlcohol: possibility of disulfiram-like reaction whenlevamisole given with alcohol. Anticoagulants: levamisole possibly enhances anticoagulanteffect of .warfarinAntiepileptics: levamisole possibly increases plasmaconcentration of phenytoinLevetiracetam. Antidepressants: anticonvulsant effect of antiepilepticspossibly antagonised by MAOIs and .tricyclic-relatedantidepressants (convulsive threshold lowered); anticonvulsanteffect of antiepileptics antagonised by.SSRIs and .tricyclics (convulsive thresholdlowered); avoid concomitant use of antiepilepticswith .St John’s wortAntiepileptics: levetiracetam possibly increases risk ofcarbamazepine toxicity. 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). Orlistat: possible increased risk of convulsions whenantiepileptics given with .orlistatLevobunolol see Beta-blockersLevobupivacaineAnti-arrhythmics: increased myocardial depressionwhen levobupivacaine given with anti-arrhythmicsLevocetirizine see AntihistaminesLevodopaACE Inhibitors: enhanced hypotensive effect whenlevodopa given with ACE inhibitorsAdrenergic Neurone Blockers: enhanced hypotensiveeffect when levodopa given with adrenergic neuroneblockersAlpha-blockers: enhanced hypotensive effect whenlevodopa given with alpha-blockers. Anaesthetics, General: increased risk of arrhythmiaswhen levodopa given with .volatile liquid generalanaestheticsAngiotensin-II Receptor Antagonists: enhancedhypotensive effect when levodopa given with angiotensin-IIreceptor antagonistsAntibacterials: effects of levodopa possibly reduced byisoniazid. Antidepressants: risk of hypertensive crisis whenlevodopa given with .MAOIs, avoid levodopa for atleast 2 weeks after stopping MAOIs; increased risk ofside-effects when levodopa given with moclobemideAntiepileptics: effects of levodopa possibly reduced byphenytoinAntimuscarinics: absorption of levodopa possiblyreduced by antimuscarinicsAntipsychotics: effects of levodopa antagonised byantipsychotics; avoidance of levodopa advised bymanufacturer of amisulpride (antagonism of effect)Anxiolytics and Hypnotics: effects of levodopa possiblyantagonised by benzodiazepinesBeta-blockers: enhanced hypotensive effect whenlevodopa given with beta-blockersBupropion: increased risk of side-effects when levodopagiven with bupropionCalcium-channel Blockers: enhanced hypotensiveeffect when levodopa given with calcium-channelblockers