Dosing & Uses
Dosage Forms & Strengths
tablets
- 10mg
- 20mg
Asthma
Indicated for chronic asthma treatment and prophylaxis
20 mg PO twice daily
Administration
Take at least 1 hour before or 2 hours after meals
Take at regular intervals
Hepatic Impairment
Contraindicated
Renal Impairment
Dose adjustment not necessary
Dosage Forms & Strengths
tablets
- 10mg
- 20mg
Asthma
<5 years: Safety and efficacy not established
5-12 years: 10 mg PO twice daily
>12 years: 20 mg PO twice daily
Administration
Take at least 1 hour before or 2 hours after meals
Take at regular intervals
Hepatic Impairment
Contraindicated
Renal Impairment
Dose adjustment not necessary
Clearance reduced in patients aged 65 yr or older (Cmax and AUC 2- to 3-fold higher than in younger patients)
Potential for increased incidence of adverse effects; use caution
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (1)
- fezolinetant
zafirlukast will increase the level or effect of fezolinetant by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated. Fezolinetant AUC and peak plasma concentration are increased if coadministered with drugs that are weak, moderate, or strong CYP1A2 inhibitors
Serious - Use Alternative (23)
- dihydroergotamine
zafirlukast will increase the level or effect of dihydroergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- dihydroergotamine intranasal
zafirlukast will increase the level or effect of dihydroergotamine intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- dronedarone
zafirlukast will increase the level or effect of dronedarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- erdafitinib
zafirlukast will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.
- ergotamine
zafirlukast will increase the level or effect of ergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- erythromycin base
zafirlukast will increase the level or effect of erythromycin base by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- erythromycin ethylsuccinate
zafirlukast will increase the level or effect of erythromycin ethylsuccinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- erythromycin lactobionate
zafirlukast will increase the level or effect of erythromycin lactobionate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- erythromycin stearate
zafirlukast will increase the level or effect of erythromycin stearate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- everolimus
zafirlukast will increase the level or effect of everolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- fedratinib
zafirlukast will increase the level or effect of fedratinib by Other (see comment). Avoid or Use Alternate Drug. Avoid coadministration of fedratinib (a CYP3A4 and CYP2C19 substrate) with dual CYP3A4 and CYP2C19 inhibitor. Effect of coadministration of a dual CYP3A4 and CYP2C19 inhibitor with fedratinib has not been studied.
- ivosidenib
ivosidenib will decrease the level or effect of zafirlukast by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP2C9 substrates with ivosidenib or replace with alternate therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.
- lonafarnib
zafirlukast will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of lonafarnib (a sensitive CYP3A substrate) with weak CYP3A inhibitors is unavoidable, reduce to, or continue lonafarnib at starting dose. Closely monitor for arrhythmias and events (eg, syncope, heart palpitations) since lonafarnib effect on QT interval is unknown.
- lovastatin
zafirlukast will increase the level or effect of lovastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- pazopanib
zafirlukast will increase the level or effect of pazopanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of pazopanib with strong CYP3A4 inhibitors if possible; if must coadminister, decrease pazopanib dose to 400 mg/day
- pimozide
zafirlukast increases levels of pimozide by decreasing metabolism. Contraindicated. Risk of QT interval prolongation.
- ranolazine
zafirlukast will increase the level or effect of ranolazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- silodosin
zafirlukast will increase the level or effect of silodosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- simvastatin
zafirlukast will increase the level or effect of simvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- siponimod
zafirlukast will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
- sirolimus
zafirlukast will increase the level or effect of sirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- tolvaptan
zafirlukast will increase the level or effect of tolvaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- zavegepant intranasal
zafirlukast will increase the level or effect of zavegepant intranasal by Other (see comment). Avoid or Use Alternate Drug. NTCP inhibitors may result in a significant increase in systemic exposure of zavegepant (a NTCP substrate).
Monitor Closely (114)
- almotriptan
zafirlukast will increase the level or effect of almotriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- alpelisib
alpelisib will decrease the level or effect of zafirlukast by affecting hepatic enzyme CYP2C9/10 metabolism. Modify Therapy/Monitor Closely.
- alprazolam
zafirlukast will increase the level or effect of alprazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- amiodarone
zafirlukast will increase the level or effect of amiodarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- apalutamide
apalutamide will decrease the level or effect of zafirlukast by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. Coadministration of apalutamide, a weak CYP2C9 inducer, with drugs that are CYP2C9 substrates can result in lower exposure to these medications. Evaluate for loss of therapeutic effect if medication must be coadministered.
- aprepitant
zafirlukast will increase the level or effect of aprepitant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- aripiprazole
zafirlukast will increase the level or effect of aripiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- artemether/lumefantrine
zafirlukast will increase the level or effect of artemether/lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- atogepant
zafirlukast will increase the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- atorvastatin
zafirlukast will increase the level or effect of atorvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- avanafil
zafirlukast will increase the level or effect of avanafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inhibitors may reduce avanafil clearance increasing systemic exposure to avanafil; increased levels may result in increased associated adverse events; the maximum recommended dose of STENDRA is 50 mg, not to exceed once every 24 hours for patients taking concomitant moderate CYP3A4 inhibitors
- avapritinib
zafirlukast will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- axitinib
zafirlukast increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- bazedoxifene/conjugated estrogens
zafirlukast will increase the level or effect of bazedoxifene/conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- bortezomib
zafirlukast will increase the level or effect of bortezomib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- budesonide
zafirlukast will increase the level or effect of budesonide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- buspirone
zafirlukast will increase the level or effect of buspirone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- cannabidiol
cannabidiol will increase the level or effect of zafirlukast by decreasing metabolism. Modify Therapy/Monitor Closely. Cannabidiol may potentially inhibit CYP2C9 activity. Consider reducing the dose when concomitantly using CYP2C9 substrates.
- carbamazepine
zafirlukast will increase the level or effect of carbamazepine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- carvedilol
zafirlukast will increase the level or effect of carvedilol by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
- cilostazol
zafirlukast will increase the level or effect of cilostazol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- cinacalcet
zafirlukast will increase the level or effect of cinacalcet by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- clopidogrel
zafirlukast will decrease the level or effect of clopidogrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Inhibition of CYP3A4 will reduce clopidogrel bioactivation
- clozapine
zafirlukast will increase the level or effect of clozapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- conivaptan
zafirlukast will increase the level or effect of conivaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- conjugated estrogens
zafirlukast will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- conjugated estrogens, vaginal
zafirlukast will increase the level or effect of conjugated estrogens, vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- cortisone
zafirlukast will increase the level or effect of cortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- darifenacin
zafirlukast will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- darunavir
zafirlukast will increase the level or effect of darunavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- dasatinib
zafirlukast will increase the level or effect of dasatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- deflazacort
zafirlukast will increase the level or effect of deflazacort by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Decrease deflazacort dose to one-third of the recommended dose if coadministered with moderate or strong CYP3A4 inhibitors.
- dexamethasone
zafirlukast will increase the level or effect of dexamethasone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- diazepam
zafirlukast will increase the level or effect of diazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- dienogest/estradiol valerate
zafirlukast will increase the level or effect of dienogest/estradiol valerate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor for potential adverse effects such as nausea, irregular uterine bleeding, breast tenderness and headache.
- eletriptan
zafirlukast will increase the level or effect of eletriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- elvitegravir/cobicistat/emtricitabine/tenofovir DF
elvitegravir/cobicistat/emtricitabine/tenofovir DF decreases levels of zafirlukast by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. Elvitegravir is a moderate CYP2C9 inducer.
- erlotinib
zafirlukast will increase the level or effect of erlotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- estradiol
zafirlukast will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- estrogens conjugated synthetic
zafirlukast will increase the level or effect of estrogens conjugated synthetic by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- estrogens esterified
zafirlukast will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- estropipate
zafirlukast will increase the level or effect of estropipate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- ethotoin
zafirlukast will increase the level or effect of ethotoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
- etonogestrel
zafirlukast will increase the level or effect of etonogestrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- etravirine
zafirlukast will increase the level or effect of etravirine by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
zafirlukast will increase the level or effect of etravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. - felodipine
zafirlukast will increase the level or effect of felodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- fesoterodine
zafirlukast will increase the level or effect of fesoterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- finerenone
zafirlukast will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or weak CYP3A4 inhibitors. Adjust finererone dosage as needed.
- flibanserin
zafirlukast will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased flibanserin adverse effects may occur if coadministered with multiple weak CYP3A4 inhibitors.
- fludrocortisone
zafirlukast will increase the level or effect of fludrocortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- fosamprenavir
zafirlukast will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- fosaprepitant
zafirlukast will increase the level or effect of fosaprepitant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- fosphenytoin
zafirlukast will increase the level or effect of fosphenytoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
- hydrocortisone
zafirlukast will increase the level or effect of hydrocortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- hydroxyprogesterone caproate (DSC)
zafirlukast will increase the level or effect of hydroxyprogesterone caproate (DSC) by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- iloperidone
zafirlukast will increase the level or effect of iloperidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- indinavir
zafirlukast will increase the level or effect of indinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- isavuconazonium sulfate
zafirlukast will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- ivacaftor
zafirlukast increases levels of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor when coadministered with weak CYP3A4 inhibitors .
- ixabepilone
zafirlukast will increase the level or effect of ixabepilone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- lapatinib
zafirlukast will increase the level or effect of lapatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- lemborexant
zafirlukast will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Lower nightly dose of lemborexant recommended if coadministered with weak CYP3A4 inhibitors. See drug monograph for specific dosage modification.
- lomitapide
zafirlukast increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.
- lopinavir
zafirlukast will increase the level or effect of lopinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- loratadine
zafirlukast will increase the level or effect of loratadine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- losartan
zafirlukast will increase the level or effect of losartan by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. May inhibit the conversion of losartan to its active metabolite E-3174. Importance of interaction not established; monitor individual therapeutic response to determine losartan dosage.
zafirlukast decreases effects of losartan by decreasing metabolism. Use Caution/Monitor. May inhibit the conversion of losartan to its active metabolite E-3174. Importance of interaction not established; monitor individual therapeutic response to determine losartan dosage. - lumacaftor/ivacaftor
lumacaftor/ivacaftor, zafirlukast. affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. In vitro studies suggest that lumacaftor may induce and ivacaftor may inhibit CYP2C9 substrates. .
- lumefantrine
zafirlukast will increase the level or effect of lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- lurasidone
zafirlukast increases levels of lurasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Concurrent use of weak CYP3A4 inhibitors can theoretically lead to an increased risk of lurasidone-related adverse reactions.
- maraviroc
zafirlukast will increase the level or effect of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- mavacamten
zafirlukast will increase the level or effect of mavacamten by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Inititiation of weak CYP2C19 inhibitors may require decreased mavacamten dose.
- mestranol
zafirlukast will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- methadone
zafirlukast will increase the level or effect of methadone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- methylprednisolone
zafirlukast will increase the level or effect of methylprednisolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- midazolam
zafirlukast will increase the level or effect of midazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- midazolam intranasal
zafirlukast will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of mild CYP3A4 inhibitors with midazolam intranasal may cause higher midazolam systemic exposure, which may prolong sedation.
- nateglinide
zafirlukast will increase the level or effect of nateglinide by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
- nelfinavir
zafirlukast will increase the level or effect of nelfinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- nicardipine
zafirlukast will increase the level or effect of nicardipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- nilotinib
zafirlukast will increase the level or effect of nilotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- nisoldipine
zafirlukast will increase the level or effect of nisoldipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- nitisinone
nitisinone will increase the level or effect of zafirlukast by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. Nitisinone inhibits CYP2C9. Caution if CYP2C9 substrate coadministered, particularly those with a narrow therapeutic index.
- parecoxib
zafirlukast will increase the level or effect of parecoxib by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
- peginterferon alfa 2b
peginterferon alfa 2b decreases levels of zafirlukast by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. When patients are administered peginterferon alpha-2b with CYP2C9 substrates, the therapeutic effect of these drugs may be altered. .
- phenytoin
zafirlukast will increase the level or effect of phenytoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
- prednisolone
zafirlukast will increase the level or effect of prednisolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- prednisone
zafirlukast will increase the level or effect of prednisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- quetiapine
zafirlukast will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- quinidine
zafirlukast will increase the level or effect of quinidine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- repaglinide
zafirlukast will increase the level or effect of repaglinide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- ritonavir
zafirlukast will increase the level or effect of ritonavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- roflumilast
zafirlukast increases levels of roflumilast by Other (see comment). Modify Therapy/Monitor Closely. Comment: Coadministration with dual inhibitors of CYP3A4 and CYP1A2 may increase systemic exposure and result in increased adverse reactions.
- romidepsin
zafirlukast will increase the level or effect of romidepsin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- rucaparib
rucaparib will increase the level or effect of zafirlukast by affecting hepatic enzyme CYP2C9/10 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP2C9 substrates, if clinically indicated.
- saquinavir
zafirlukast will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- sildenafil
zafirlukast will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- solifenacin
zafirlukast will increase the level or effect of solifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- sparsentan
sparsentan will decrease the level or effect of zafirlukast by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. Sparsentan (a CYP2C9 inducer) decreases exposure of CYP2C9 substrates and reduces efficacy related to these substrates.
- sunitinib
zafirlukast will increase the level or effect of sunitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- tacrolimus
zafirlukast will increase the level or effect of tacrolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- tadalafil
zafirlukast will increase the level or effect of tadalafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- tamoxifen
zafirlukast, tamoxifen. affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. CYP2C9/10 inhibition decreases tamoxifen metabolism to active metabolites.
- tazemetostat
zafirlukast will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- temsirolimus
zafirlukast will increase the level or effect of temsirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- theophylline
zafirlukast will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- tinidazole
zafirlukast will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- tipranavir
zafirlukast will increase the level or effect of tipranavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- tolterodine
zafirlukast will increase the level or effect of tolterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- triamcinolone acetonide injectable suspension
zafirlukast will increase the level or effect of triamcinolone acetonide injectable suspension by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- triazolam
zafirlukast will increase the level or effect of triazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- vardenafil
zafirlukast will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- verapamil
zafirlukast will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- vilazodone
vilazodone increases levels of zafirlukast by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dose adjustment needed with mild CYP3A4 inhibitors.
- warfarin
zafirlukast will increase the level or effect of warfarin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
Minor (70)
- alfentanil
zafirlukast will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- alfuzosin
zafirlukast will increase the level or effect of alfuzosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- alosetron
zafirlukast will increase the level or effect of alosetron by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
zafirlukast will increase the level or effect of alosetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. - amitriptyline
zafirlukast will increase the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- armodafinil
zafirlukast will increase the level or effect of armodafinil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- aspirin
aspirin increases levels of zafirlukast by unknown mechanism. Minor/Significance Unknown.
- aspirin rectal
aspirin rectal increases levels of zafirlukast by unknown mechanism. Minor/Significance Unknown.
- aspirin/citric acid/sodium bicarbonate
aspirin/citric acid/sodium bicarbonate increases levels of zafirlukast by unknown mechanism. Minor/Significance Unknown.
- atazanavir
zafirlukast will increase the level or effect of atazanavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- bosentan
zafirlukast will increase the level or effect of bosentan by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
zafirlukast will increase the level or effect of bosentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. - celecoxib
zafirlukast will increase the level or effect of celecoxib by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
- cevimeline
zafirlukast will increase the level or effect of cevimeline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- clarithromycin
zafirlukast will increase the level or effect of clarithromycin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- clomipramine
zafirlukast will increase the level or effect of clomipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- dapsone
zafirlukast will increase the level or effect of dapsone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- diclofenac
zafirlukast will increase the level or effect of diclofenac by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
- disopyramide
zafirlukast will increase the level or effect of disopyramide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- docetaxel
zafirlukast will increase the level or effect of docetaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- donepezil
zafirlukast will increase the level or effect of donepezil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- dutasteride
zafirlukast will increase the level or effect of dutasteride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- efavirenz
zafirlukast will increase the level or effect of efavirenz by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- eplerenone
zafirlukast will increase the level or effect of eplerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- erythromycin base
erythromycin base decreases levels of zafirlukast by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- erythromycin ethylsuccinate
erythromycin ethylsuccinate decreases levels of zafirlukast by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- erythromycin lactobionate
erythromycin lactobionate decreases levels of zafirlukast by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- erythromycin stearate
erythromycin stearate decreases levels of zafirlukast by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- eucalyptus
zafirlukast will increase the level or effect of eucalyptus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- finasteride
zafirlukast will increase the level or effect of finasteride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- flurbiprofen
zafirlukast will increase the level or effect of flurbiprofen by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
- fluvastatin
zafirlukast will increase the level or effect of fluvastatin by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
- galantamine
zafirlukast will increase the level or effect of galantamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- ibuprofen
zafirlukast will increase the level or effect of ibuprofen by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
- ibuprofen IV
zafirlukast will increase the level or effect of ibuprofen IV by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
- imatinib
zafirlukast will increase the level or effect of imatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- imipramine
zafirlukast will increase the level or effect of imipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- isradipine
zafirlukast will increase the level or effect of isradipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- itraconazole
zafirlukast will increase the level or effect of itraconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- ketoconazole
zafirlukast will increase the level or effect of ketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- levoketoconazole
zafirlukast will increase the level or effect of levoketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- meloxicam
zafirlukast will increase the level or effect of meloxicam by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
- montelukast
zafirlukast will increase the level or effect of montelukast by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- nifedipine
zafirlukast will increase the level or effect of nifedipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- nimodipine
zafirlukast will increase the level or effect of nimodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- nitrendipine
zafirlukast will increase the level or effect of nitrendipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- oxybutynin
zafirlukast will increase the level or effect of oxybutynin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- paclitaxel
zafirlukast will increase the level or effect of paclitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- paclitaxel protein bound
zafirlukast will increase the level or effect of paclitaxel protein bound by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- parecoxib
zafirlukast will increase the level or effect of parecoxib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- pimozide
zafirlukast will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- pioglitazone
zafirlukast will increase the level or effect of pioglitazone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- piroxicam
zafirlukast will increase the level or effect of piroxicam by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
- propafenone
zafirlukast will increase the level or effect of propafenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- quinine
zafirlukast will increase the level or effect of quinine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- ramelteon
zafirlukast will increase the level or effect of ramelteon by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
zafirlukast will increase the level or effect of ramelteon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. - ruxolitinib
zafirlukast will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- ruxolitinib topical
zafirlukast will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- saxagliptin
zafirlukast will increase the level or effect of saxagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- sufentanil
zafirlukast will increase the level or effect of sufentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- sulfamethoxazole
zafirlukast will increase the level or effect of sulfamethoxazole by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
- theophylline
theophylline decreases levels of zafirlukast by unknown mechanism. Minor/Significance Unknown.
- tolbutamide
zafirlukast will increase the level or effect of tolbutamide by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
- trazodone
zafirlukast will increase the level or effect of trazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- vinblastine
zafirlukast will increase the level or effect of vinblastine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- vincristine
zafirlukast will increase the level or effect of vincristine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- vincristine liposomal
zafirlukast will increase the level or effect of vincristine liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- vinorelbine
zafirlukast will increase the level or effect of vinorelbine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- voriconazole
zafirlukast will increase the level or effect of voriconazole by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
- ziprasidone
zafirlukast will increase the level or effect of ziprasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- zolpidem
zafirlukast will increase the level or effect of zolpidem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- zonisamide
zafirlukast will increase the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
Adverse Effects
>10%
headache (12.9% in age >12 yr)
1-10%
Abdominal pain (1.8%)
Infection (3.5%)
Nausea (3.1%)
Diarrhea (2.8%)
Generalized pain (1.8%)
Vomiting (1.5%)
Dyspepsia/gastritits (1.3%)
Increased ALT (1.5%)
Infection (4%)
Back pain (2%)
Weakness (2%)
Myalgia (2%)
Frequency Not Defined
Eosinophilia
Eosinophilic pneumonia
Vasculitis
Malaise
Bleeding
Bruising
Warnings
Contraindications
Hypersensitivity
Hepatic impairment, including cirrhosis; Cmax and AUC ~50-60% greater than those of normal adults
Cautions
Increased risk of infection if age >55 yr
Not indicated for use in the reversal of bronchospasm in acute asthma attacks, including status asthmaticus; therapy can be continued during acute exacerbations of asthma
Coadministration of zafirlukast with warfarin results in a clinically significant increase in prothrombin time (PT); patients on oral warfarin anticoagulant therapy and this drug should have their prothrombin times monitored closely and anticoagulant dose adjusted accordingly
Indicated for the chronic treatment of asthma; should be taken regularly as prescribed, even during symptom-free periods; this drug is not a bronchodilator and should not be used to treat acute episodes of asthma
Patients receiving therapy should be instructed not to decrease the dose or stop taking any other antiasthma medications unless instructed by a physician
Patients should be instructed to notify their physician if neuropsychiatric events occur while using this drug; women who are breast-feeding should be instructed not to take this medication; alternative antiasthma medication should be considered in such patients
Bioavailability of this medication may be decreased when taken with food; patients should be instructed to take the medication at least 1 hour before or 2 hours after meals
Eosinophillic conditions
- In rare cases, patients with asthma on this medication may present with systemic eosinophilia, eosinophilic pneumonia, or clinical features of vasculitis consistent with Churg-Strauss syndrome, a condition which is often treated with systemic steroid therapy; physicians should be alert to eosinophilia, vasculitic rash, worsening pulmonary symptoms, cardiac complications, and/or neuropathy presenting in their patients
- These events have usually, but not always, been associated with reductions and/or withdrawal of steroid therapy; the possibility that this medication may be associated with emergence of Churg-Strauss syndrome can neither be excluded nor established
Neuropsychiatric events
- Neuropsychiatric events have been reported in adult, adolescent and pediatric patients taking this medication; post-marketing reports include insomnia and depression
- The clinical details of some post-marketing reports involving this medication appear consistent with a drug-induced effect; patients and prescribers should be alert for neuropsychiatric events; patients should be instructed to notify their prescriber if these changes occur
- Prescribers should carefully evaluate the risks and benefits of continuing treatment with this medication if such events occur
Hepatotoxicity
- Cases of life-threatening hepatic failure reported; cases of liver injury without other attributable cause reported from post-marketing adverse event surveillance of patients who have received recommended dose (40 mg/day)
- In most, but not all post-marketing reports, the patient’s symptoms abated and the liver enzymes returned to normal or near-normal after stopping therapy
- In rare cases, patients have either presented with fulminant hepatitis or progressed to hepatic failure, liver transplantation and death; in rare post-marketing cases, no clinical symptoms or signs suggestive of liver dysfunction were reported to precede the latter observations
- Physicians may consider the value of liver function testing.; periodic serum transaminase testing has not proven to prevent serious injury but it is generally believed that early detection of drug-induced hepatic injury along with immediate withdrawal of the suspect drug enhances likelihood for recovery
- Patients should be advised to be alert for signs and symptoms of liver dysfunction (eg, right upper quadrant abdominal pain, nausea, fatigue, lethargy, pruritus, jaundice, flu-like symptoms, and anorexia) and to contact their physician immediately if they occur; ongoing clinical assessment of patients should govern physician interventions, including diagnostic evaluations and treatment
- If liver dysfunction is suspected based upon clinical signs or symptoms (eg, right upper quadrant abdominal pain, nausea, fatigue, lethargy, pruritus, jaundice, flu-like symptoms, anorexia, and enlarged liver), should be discontinued
- Liver function tests, in particular serum ALT, should be measured immediately and the patient managed accordingly; if liver function tests are consistent with hepatic dysfunction, therapy should not be resumed; patients in whom therapy was withdrawn because of hepatic dysfunction where no other attributable cause is identified should not be re-exposed to the drug
Pregnancy & Lactation
Pregnancy
No teratogenicity was observed at oral doses up to 1600 mg/kg/day in mice (approximately 160 times maximum recommended daily oral dose in adults on mg/m2 basis), up to 2000 mg/kg/day in rats (approximately 410 times the maximum recommended daily oral dose in adults on mg/m2 basis) and up to 2000 mg/kg/day in cynomolgus monkeys (which resulted in approximately 20 times the exposure to drug plus metabolites compared to that from the maximum recommended daily oral dose in adults based on comparison of the AUC values)
At an oral dose of 2000 mg/kg/day in rats, maternal toxicity and deaths were seen with increased incidence of early fetal resorption; spontaneous abortions occurred in cynomolgus monkeys at the maternally toxic oral dose of 2000 mg/kg/day; there are no adequate and well-controlled trials in pregnant women; because animal reproduction studies are not always predictive of human response, this medication should be used during pregnancy only if clearly needed
Lactation
This medication is excreted in breast milk; following repeated 40 mg twice-a-day dosing in healthy women, average steady-state concentrations in breast milk were 50 ng/mL compared to 255 ng/mL in plasma; because of potential for tumorigenicity shown in mouse and rat studies and the enhanced sensitivity of neonatal rats and dogs to adverse effects of this medication should not be administered to mothers who are breast-feeding
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Inhibits bronchoconstriction as competitive receptor antagonist of leukotrienes D4 & E4; receptor occupation and cysteinyl leukotriene production has been associated with the pathophysiology of ashtma
Pharmacokinetics
Half-Life: 8-16 hr
Onset: 3-14 days
Peak plasma concentration: 326 ng/mL (healthy subjects); 568 ng/mL (asthmatics)
Peak plasm time: 3 hr (healthy subjects); 3.5 hr (asthmatics)
Clearance: 20 L/hr; significantly decreased in cirrhosis and age 65 yr
Protein bound: 99%
Vd: 70 L
Bioavailability: Reduced 40% with food
Metabolism: Hepatic CYP2C9
Excretion: Feces (90%); urine (10%)
Enzymes inhibited: Hepatic CYP2C9, CYP3A4
Images
Patient Handout
zafirlukast oral
ZAFIRLUKAST - ORAL
(ZA-fir-LOO-kast)
COMMON BRAND NAME(S): Accolate
USES: Zafirlukast is used to control and prevent symptoms (such as wheezing and shortness of breath) caused by asthma. Controlling symptoms of asthma helps you maintain your normal activities and cuts down on time lost from work or school.This medication must be used regularly to be effective. It does not work right away and should not be used to relieve sudden asthma attacks. If an asthma attack occurs, use your quick-relief inhaler (such as albuterol, salbutamol) as prescribed.
HOW TO USE: Read the Patient Information Leaflet if available from your pharmacist before you start taking zafirlukast and each time you get a refill. If you have any questions, ask your doctor or pharmacist.Take this medication by mouth without food as directed by your doctor, usually 2 times daily. Take zafirlukast on an empty stomach at least 1 hour before or 2 hours after meals. The dosage is based on your age.Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day. Keep taking this medication even if you feel well. Do not increase your dose, use this drug more often, or stop using it without first consulting your doctor.Get medical help right away if your asthma symptoms worsen or if you are using your quick-relief inhaler more than usual or more often than prescribed.
SIDE EFFECTS: Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: mental/mood changes (such as trouble sleeping, agitation, hallucinations, depression, thoughts of suicide), signs of infection (such as sore throat that doesn't go away, fever, cough), numbness/tingling of arms/legs, chest pain, coughing up blood, worsening shortness of breath, muscle/joint pain, swelling ankles/feet.This drug may rarely cause serious (possibly fatal) liver disease. Get medical help right away if you have any symptoms of liver damage, such as: nausea/vomiting that doesn't stop, loss of appetite, stomach/abdominal pain, yellowing eyes/skin, dark urine.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking zafirlukast, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver disease, alcohol use.Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).Older adults may be more sensitive to the side effects of this drug.During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.This medication passes into breast milk. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Other medications can affect the removal of zafirlukast from your body, which may affect how zafirlukast works. An example is erythromycin, among others.This medication can slow down the removal of other medications from your body, which may affect how they work. An example is warfarin, among others.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
NOTES: Do not share this medication with others.Lab and/or medical tests (such as liver/lung function) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.Avoid substances that can worsen breathing problems by causing irritation or allergic reaction, such as smoke, pollen, pet dander, dust, and mold.
MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
MEDICAL ALERT: Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).
Information last revised August 2021. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Formulary
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