BNF for Children 2011-2012

BNFC 2011–2012 Appendix 1: Interactions 659Alpha 2 -adrenoceptor Stimulants see Apraclonidine,Brimonidine, Clonidine and MethyldopaAlpha-blockersACE Inhibitors: enhanced hypotensive effect whenalpha-blockers given with ACE inhibitorsAdrenergic Neurone Blockers: enhanced hypotensiveeffect when alpha-blockers given with adrenergicneurone blockersAlcohol: enhanced hypotensive effect when alphablockersgiven with alcohol; increased sedative effectwhen indoramin given with alcoholAldesleukin: enhanced hypotensive effect when alphablockersgiven with aldesleukin. Anaesthetics, General: enhanced hypotensive effectwhen alpha-blockers given with .general anaestheticsAnalgesics: hypotensive effect of alpha-blockersantagonised by NSAIDsAngiotensin-II Receptor Antagonists: enhancedhypotensive effect when alpha-blockers given withangiotensin-II receptor antagonists. Antidepressants: enhanced hypotensive effect whenalpha-blockers given with MAOIs; manufacturer ofindoramin advises avoid concomitant use with.MAOIsAntifungals: plasma concentration of alfuzosin possiblyincreased by ketoconazoleAntipsychotics: enhanced hypotensive effect whenalpha-blockers given with antipsychotics. Antivirals: plasma concentration of alfuzosin possiblyincreased by .ritonavir—avoid concomitant useAnxiolytics and Hypnotics: enhanced hypotensive andsedative effects when alpha-blockers given withanxiolytics and hypnotics. Beta-blockers: enhanced hypotensive effect whenalpha-blockers given with .beta-blockers, alsoincreased risk of first-dose hypotension with postsynapticalpha-blockers such as prazosin. Calcium-channel Blockers: enhanced hypotensiveeffect when alpha-blockers given with .calciumchannelblockers, also increased risk of first-dosehypotension with post-synaptic alpha-blockers suchas prazosinCardiac Glycosides: prazosin increases plasma concentrationof digoxinClonidine: enhanced hypotensive effect when alphablockersgiven with clonidineCorticosteroids: hypotensive effect of alpha-blockersantagonised by corticosteroidsDiazoxide: enhanced hypotensive effect when alphablockersgiven with diazoxide. Diuretics: enhanced hypotensive effect when alphablockersgiven with .diuretics, also increased risk offirst-dose hypotension with post-synaptic alphablockerssuch as prazosinDopaminergics: enhanced hypotensive effect whenalpha-blockers given with levodopaMethyldopa: enhanced hypotensive effect when alphablockersgiven with methyldopa. Moxisylyte: possible severe postural hypotension whenalpha-blockers given with .moxisylyteMoxonidine: enhanced hypotensive effect when alphablockersgiven with moxonidineMuscle Relaxants: enhanced hypotensive effect whenalpha-blockers given with baclofen or tizanidineNitrates: enhanced hypotensive effect when alphablockersgiven with nitratesOestrogens: hypotensive effect of alpha-blockersantagonised by oestrogensProstaglandins: enhanced hypotensive effect whenalpha-blockers given with alprostadil. Sildenafil: enhanced hypotensive effect when alphablockersgiven with .sildenafil (avoid alpha-blockersfor 4 hours after sildenafil)—see also under Phosphodiesterasetype-5 inhibitors, BNF section 7.4.5. Sympathomimetics: avoid concomitant use of tolazolinewith .adrenaline (epinephrine) or .dopamine. Tadalafil: enhanced hypotensive effect when alphablockersgiven with .tadalafil—see also under Phos-Alpha-blockers. Tadalafil (continued)phodiesterase type-5 inhibitors, BNF section7.4.5; enhanced hypotensive effect when doxazosingiven with .tadalafil—manufacturer oftadalafil advises avoid concomitant use. Ulcer-healing Drugs: effects of tolazoline antagonisedby .cimetidine and .ranitidine. Vardenafil: enhanced hypotensive effect when alphablockers(excludes tamsulosin) given with.vardenafil—separate doses by 6 hours—see alsounder Phosphodiesterase type-5 inhibitors, BNFsection 7.4.5Vasodilator Antihypertensives: enhanced hypotensiveeffect when alpha-blockers given with hydralazine,minoxidil or sodium nitroprussideAlpha-blockers (post-synaptic) see Alpha-blockersAlprazolam see Anxiolytics and HypnoticsAlprostadil see ProstaglandinsAluminium Hydroxide see AntacidsAmantadineAntimalarials: plasma concentration of amantadinepossibly increased by quinineAntipsychotics: increased risk of extrapyramidal sideeffectswhen amantadine given with antipsychoticsBupropion: increased risk of side-effects when amantadinegiven with bupropion. Memantine: increased risk of CNS toxicity whenamantadine given with .memantine (manufacturer ofmemantine advises avoid concomitant use); effects ofdopaminergics possibly enhanced by memantineMethyldopa: increased risk of extrapyramidal sideeffectswhen amantadine given with methyldopa;antiparkinsonian effect of dopaminergics antagonisedby methyldopaTetrabenazine: increased risk of extrapyramidal sideeffectswhen amantadine given with tetrabenazineAmikacin see AminoglycosidesAmiloride see DiureticsAminoglycosidesAgalsidase Alfa and Beta: gentamicin possibly inhibitseffects of agalsidase alfa and beta (manufacturers ofagalsidase alfa and beta advise avoid concomitantuse)Analgesics: plasma concentration of amikacin andgentamicin in neonates possibly increased by indometacin. Antibacterials: neomycin reduces absorption ofphenoxymethylpenicillin; increased risk of nephrotoxicitywhen aminoglycosides given with colistimethatesodium or polymyxins; increased risk ofnephrotoxicity and ototoxicity when aminoglycosidesgiven with capreomycin or .vancomycin; possibleincreased risk of nephrotoxicity when aminoglycosidesgiven with cephalosporins. Anticoagulants: experience in anticoagulant clinicssuggests that INR possibly altered when neomycin(given for local action on gut) is given with.coumarins or .phenindioneAntidiabetics: neomycin possibly enhances hypoglycaemiceffect of acarbose, also severity of gastrointestinaleffects increasedAntifungals: increased risk of nephrotoxicity whenaminoglycosides given with amphotericinBisphosphonates: increased risk of hypocalcaemiawhen aminoglycosides given with bisphosphonatesCardiac Glycosides: neomycin reduces absorption ofdigoxin; gentamicin possibly increases plasma concentrationof digoxin. Ciclosporin: increased risk of nephrotoxicity whenaminoglycosides given with .ciclosporin. Cytotoxics: neomycin possibly reduces absorption ofmethotrexate; neomycin reduces bioavailability ofsorafenib; increased risk of nephrotoxicity andpossibly of ototoxicity when aminoglycosides givenwith .platinum compounds. Diuretics: increased risk of otoxicity when aminoglycosidesgiven with .loop diureticsAppendix 1: Interactions