BNF for Children 2011-2012

BNFC 2011–2012 Appendix 1: Interactions 673Anxiolytics and Hypnotics (continued)Antihistamines: increased sedative effect whenanxiolytics and hypnotics given with antihistamines. Antipsychotics: increased sedative effect when anxiolyticsand hypnotics given with antipsychotics;buspirone increases plasma concentration of haloperidol;serious adverse events reported with concomitantuse of lorazepam and .clozapine (causalitynot established); increased risk of hypotension,bradycardia and respiratory depression when parenteralbenzodiazepines given with intramuscular.olanzapine. Antivirals: plasma concentration of midazolam possiblyincreased by .atazanavir—avoid concomitant use oforal midazolam; increased risk of prolonged sedationwhen midazolam given with .efavirenz—avoid concomitantuse; plasma concentration of midazolampossibly increased by .fosamprenavir, .indinavir,.nelfinavir and .ritonavir (risk of prolonged sedation—avoidconcomitant use of oral midazolam);increased risk of prolonged sedation when alprazolamgiven with .indinavir—avoid concomitant use;plasma concentration of alprazolam, diazepam,flurazepam and zolpidem possibly increased by.ritonavir (risk of extreme sedation and respiratorydepression—avoid concomitant use); plasma concentrationof anxiolytics and hypnotics possiblyincreased by .ritonavir; plasma concentration ofbuspirone increased by ritonavir (increased risk oftoxicity); plasma concentration of midazolamincreased by .saquinavir (risk of prolonged sedation—avoidconcomitant use of oral midazolam)Aprepitant: plasma concentration of midazolamincreased by aprepitant (risk of prolonged sedation)Beta-blockers: enhanced hypotensive effect whenanxiolytics and hypnotics given with beta-blockersCalcium-channel Blockers: enhanced hypotensiveeffect when anxiolytics and hypnotics given withcalcium-channel blockers; midazolam increasesabsorption of lercanidipine; metabolism of midazolaminhibited by diltiazem and verapamil(increased plasma concentration with increasedsedation); plasma concentration of buspironeincreased by diltiazem and verapamil (reduce dose ofbuspirone)Cardiac Glycosides: alprazolam increases plasmaconcentration of digoxin (increased risk of toxicity)Clonidine: enhanced hypotensive effect when anxiolyticsand hypnotics given with clonidineCytotoxics: plasma concentration of midazolamincreased by nilotinibDeferasirox: plasma concentration of midazolam possiblyreduced by deferasiroxDiazoxide: enhanced hypotensive effect when anxiolyticsand hypnotics given with diazoxideDisulfiram: metabolism of benzodiazepines inhibitedby disulfiram (increased sedative effects); increasedrisk of temazepam toxicity when given with disulfiramDiuretics: enhanced hypotensive effect when anxiolyticsand hypnotics given with diuretics; administrationof chloral with parenteral furosemide maydisplace thyroid hormone from binding sitesDopaminergics: benzodiazepines possibly antagoniseeffects of levodopaGrapefruit Juice: plasma concentration of buspironeincreased by grapefruit juiceLithium: increased risk of neurotoxicity when clonazepamgiven with lithiumLofexidine: increased sedative effect when anxiolyticsand hypnotics given with lofexidineMethyldopa: enhanced hypotensive effect whenanxiolytics and hypnotics given with methyldopaMoxonidine: enhanced hypotensive effect whenanxiolytics and hypnotics given with moxonidine;sedative effects possibly increased when benzodiazepinesgiven with moxonidineAnxiolytics and Hypnotics (continued)Muscle Relaxants: increased sedative effect whenanxiolytics and hypnotics given with baclofen ortizanidineNitrates: enhanced hypotensive effect when anxiolyticsand hypnotics given with nitratesOestrogens: plasma concentration of melatoninincreased by oestrogensProbenecid: excretion of lorazepam reduced by probenecid(increased plasma concentration); excretionof nitrazepam possibly reduced by probenecid(increased plasma concentration). Sodium Oxybate: benzodiazepines enhance effects of.sodium oxybate (avoid concomitant use)Theophylline: effects of benzodiazepines possiblyreduced by theophyllineUlcer-healing Drugs: plasma concentration of melatoninincreased by cimetidine; metabolism of benzodiazepines,clomethiazole and zaleplon inhibited bycimetidine (increased plasma concentration); metabolismof diazepam possibly inhibited byesomeprazole and omeprazole (increased plasmaconcentration)Vasodilator Antihypertensives: enhanced hypotensiveeffect when anxiolytics and hypnotics given withhydralazine, minoxidil or sodium nitroprussideApomorphineAntipsychotics: effects of apomorphine antagonised byantipsychoticsDopaminergics: effects of apomorphine possiblyenhanced by entacaponeMemantine: effects of dopaminergics possiblyenhanced by memantineMethyldopa: antiparkinsonian effect of dopaminergicsantagonised by methyldopaApraclonidineAntidepressants: manufacturer of apraclonidineadvises avoid concomitant use with MAOIs, tricyclicrelatedantidepressants and tricyclicsAprepitantNote Fosaprepitant is a prodrug of aprepitantAntibacterials: plasma concentration of aprepitantpossibly increased by clarithromycin and telithromycin;plasma concentration of aprepitant reduced byrifampicinAnticoagulants: aprepitant possibly reduces anticoagulanteffect of warfarin. Antidepressants: manufacturer of aprepitant advisesavoid concomitant use with .St John’s wortAntidiabetics: aprepitant reduces plasma concentrationof tolbutamideAntiepileptics: plasma concentration of aprepitantpossibly reduced by carbamazepine,phenobarbital and phenytoinAntifungals: plasma concentration of aprepitantincreased by ketoconazole. Antipsychotics: manufacturer of aprepitant advisesavoid concomitant use with .pimozideAntivirals: plasma concentration of aprepitant possiblyincreased by ritonavirAnxiolytics and Hypnotics: aprepitant increasesplasma concentration of midazolam (risk of prolongedsedation)Calcium-channel Blockers: plasma concentration ofboth drugs may increase when aprepitant given withdiltiazemCorticosteroids: aprepitant inhibits metabolism ofdexamethasone and methylprednisolone (reducedose of dexamethasone and methylprednisolone). Oestrogens: aprepitant possibly causes contraceptivefailure of hormonal contraceptives containing.oestrogens (alternative contraception recommended). Progestogens: aprepitant possibly causes contraceptivefailure of hormonal contraceptives containing.progestogens (alternative contraception recommended)Aripiprazole see AntipsychoticsAppendix 1: Interactions