BNF for Children 2011-2012

734 Appendix 1: Interactions BNFC 2011–2012Appendix 1: InteractionsSympathomimetics, Beta 2 (continued)Theophylline: increased risk of hypokalaemia whenhigh doses of beta 2 sympathomimetics given withtheophylline—see Hypokalaemia, p. 138TacrolimusNote Interactions do not generally apply to tacrolimus usedtopically; risk of facial flushing and skin irritation withalcohol consumption (p. 573) does not apply to tacrolimustaken systemically. Analgesics: possible increased risk of nephrotoxicitywhen tacrolimus given with NSAIDs; increased risk ofnephrotoxicity when tacrolimus given with.ibuprofenAngiotensin-II Receptor Antagonists: increased risk ofhyperkalaemia when tacrolimus given with angiotensin-IIreceptor antagonistsAnti-arrhythmics: caution with tacrolimus advised bymanufacturer of dronedarone. Antibacterials: plasma concentration of tacrolimusincreased by .clarithromycin and .erythromycin;plasma concentration of tacrolimus possibly reducedby rifabutin; plasma concentration of tacrolimusreduced by .rifampicin; increased risk of nephrotoxicitywhen tacrolimus given with.aminoglycosides; plasma concentration of tacrolimuspossibly increased by .chloramphenicol and.telithromycin; possible increased risk of nephrotoxicitywhen tacrolimus given with vancomycin. Antidepressants: plasma concentration of tacrolimusreduced by .St John’s wort—avoid concomitant use. Antiepileptics: plasma concentration of tacrolimusreduced by .phenobarbital; plasma concentration oftacrolimus reduced by phenytoin, also plasma concentrationof phenytoin possibly increased. Antifungals: plasma concentration of tacrolimusincreased by .fluconazole, .itraconazole,.ketoconazole, .posaconazole and .voriconazole(consider reducing dose of tacrolimus); increased riskof nephrotoxicity when tacrolimus given with.amphotericin; plasma concentration of tacrolimusreduced by .caspofungin; plasma concentration oftacrolimus possibly increased by .imidazoles. Antipsychotics: avoidance of tacrolimus advised bymanufacturer of .droperidol (risk of ventriculararrhythmias). Antivirals: possible increased risk of nephrotoxicitywhen tacrolimus given with aciclovir or ganciclovir;plasma concentration of tacrolimus possiblyincreased by .atazanavir, .nelfinavir and .ritonavir;plasma concentration of tacrolimus possibly affectedby .efavirenz; plasma concentration of tacrolimusincreased by .fosamprenavir; plasma concentrationof tacrolimus increased by .saquinavir (considerreducing dose of tacrolimus). Calcium-channel Blockers: plasma concentration oftacrolimus possibly increased by felodipine,nicardipine and verapamil; plasma concentration oftacrolimus increased by .diltiazem and .nifedipine. Ciclosporin: tacrolimus increases plasma concentrationof .ciclosporin (increased risk of nephrotoxicity)—avoid concomitant use. Diuretics: increased risk of hyperkalaemia whentacrolimus given with .potassium-sparing diureticsand aldosterone antagonists. Grapefruit Juice: plasma concentration of tacrolimusincreased by .grapefruit juiceHormone Antagonists: plasma concentration oftacrolimus possibly increased by danazolMifamurtide: avoidance of tacrolimus advised bymanufacturer of mifamurtideOestrogens: plasma concentration of tacrolimus possiblyincreased by ethinylestradiol. Potassium Salts: increased risk of hyperkalaemiawhen tacrolimus given with .potassium saltsSevelamer: plasma concentration of tacrolimus possiblyreduced by sevelamerUlcer-healing Drugs: plasma concentration of tacrolimuspossibly increased by omeprazoleTadalafil. Alpha-blockers: enhanced hypotensive effect whentadalafil given with .doxazosin—manufacturer oftadalafil advises avoid concomitant use; enhancedhypotensive effect when tadalafil given with .alphablockers—seealso under Phosphodiesterase type-5inhibitors, BNF section 7.4.5. Antibacterials: plasma concentration of tadalafil possiblyincreased by clarithromycin and erythromycin;plasma concentration of tadalafil reduced by.rifampicin—manufacturer of tadalafil advises avoidconcomitant use. Antifungals: plasma concentration of tadalafilincreased by .ketoconazole—manufacturer of tadalafiladvises avoid concomitant use; plasma concentrationof tadalafil possibly increased by itraconazole. Antivirals: plasma concentration of tadalafil possiblyincreased by fosamprenavir and indinavir; plasmaconcentration of tadalafil increased by .ritonavir—manufacturer of tadalafil advises avoid concomitantuse; increased risk of ventricular arrhythmias whentadalafil given with .saquinavir—avoid concomitantuseBosentan: plasma concentration of tadalafil reducedby bosentanGrapefruit Juice: plasma concentration of tadalafilpossibly increased by grapefruit juice. Nicorandil: tadalafil significantly enhances hypotensiveeffect of .nicorandil (avoid concomitant use). Nitrates: tadalafil significantly enhances hypotensiveeffect of .nitrates (avoid concomitant use)TamoxifenAntibacterials: metabolism of tamoxifen acceleratedby rifampicin (reduced plasma concentration). Anticoagulants: tamoxifen enhances anticoagulanteffect of .coumarins. Antidepressants: metabolism of tamoxifen to activemetabolite possibly inhibited by .fluoxetine and.paroxetine (avoid concomitant use). Antipsychotics: avoidance of tamoxifen advised bymanufacturer of .droperidol (risk of ventriculararrhythmias). Bupropion: metabolism of tamoxifen to active metabolitepossibly inhibited by .bupropion (avoid concomitantuse). Cinacalcet: metabolism of tamoxifen to active metabolitepossibly inhibited by .cinacalcet (avoid concomitantuse)Tamsulosin see Alpha-blockersTaxanes see Docetaxel and PaclitaxelTegafur with uracil see FluorouracilTeicoplaninVaccines: antibacterials inactivate oral typhoidvaccine—see p. 620Telbivudine. Interferons: increased risk of peripheral neuropathywhen telbivudine given with .interferon alfaTelithromycinAnalgesics: telithromycin inhibits the metabolism ofoxycodone. Anti-arrhythmics: avoidance of telithromycin advisedby manufacturer of .dronedarone (risk of ventriculararrhythmias). Antibacterials: plasma concentration of telithromycinreduced by .rifampicin (avoid during and for 2 weeksafter rifampicin). Antidepressants: plasma concentration of telithromycinreduced by .St John’s wort (avoid during and for2 weeks after St John’s wort). Antiepileptics: plasma concentration of telithromycinreduced by .carbamazepine, .phenobarbital and.phenytoin (avoid during and for 2 weeks aftercarbamazepine, phenobarbital and phenytoin). Antifungals: manufacturer of telithromycin advisesavoid concomitant use with .ketoconazole in severerenal and hepatic impairment