Dosing & Uses
Dosage Forms & Strengths
tablet
- 50mg
- 100mg
- 150mg
Arrhythmias (Prevention)
PSVT and paroxysmal atrial fibrillation
- 50 mg PO BID; may increase by 50 mg every 4 days; do not exceed 300 mg/day
Sustained VT
- 100 mg PO BID initiated in hospital; may increase by 50 mg every 4 days; do not exceed 400 mg/day
Dosing Considerations
Steady-state plasma levels not achieved for 3-5 days, so increases in dosage should not be made less than every 4 days
Loading dose not recommended, due to increased incidence of proarrhythmic events and CHF
Patients intolerant to BID dosing may require 8hr dosing
Once adequate control of arrhythmia has been achieved, may reduce dose, provided there is no loss of efficacy
After 5 doses/steady state, obtain ECG after initiation or change of dose; obtain plasma trough flecainide levels 1 hour predose
Usual trough plasma levels: 0.2-1 mcg/mL
When given concomitantly with amiodarone, reduce flecainide dose by 50% and monitor closely
Dose cautiously in patients with history of MI or CHF
When switching from another antiarrhythmic to flecainide, allow >2-4 plasma half-lives to elapse before starting flecainide; if discontinuation of previous drug may produce life-threatening arrhythmias, consider hospitalizing patient
Dosage Modifications
Renal impairment
- Severe (<35 mL/min): 100 mg PO qDay or 50 mg PO BID
- >25 mL/min: 100 mg PO BID
Hepatic impairment
- Use only if benefits outweigh risk; monitor plasma levels regularly; reduce dose as necessary
Narcolepsy (Orphan)
Orphan designation of a fixed dose combination of modafinil and flecainide for narcolepsy
Sponsor
- Theranexus SA; 86 Rue de Paris; Orsay, France
Dosage Forms & Strengths
tablet
- 50mg
- 100mg
- 150mg
Arrhythmias
<6 months: 50 mg/m²/day PO divided q8-12hr
≥6 months: 100 mg/m²/day PO divided q8-12hr
Not to exceed 200 mg/m²/day
Dosing Considerations
Usual therapeutic level: 200-500 ng/mL; some may require <800 ng/mL for adequate control
Steady-state plasma levels not achieved for 3-5 days, so increases in dosage should not be made less than every 4 days
Loading dose not recommended, due to increased incidence of proarrhythmic events and CHF
Patients intolerant to BID dosing may require 8hr dosing
Once adequate control of arrhythmia has been achieved, may reduce dose, provided there is no loss of efficacy
After 5 doses/steady state, obtain ECG after initiation or change of dose; obtain plasma trough flecainide levels 1 hour predose
Usual trough plasma levels: 0.2-1 mcg/mL
When given concomitantly with amiodarone, reduce flecainide dose by 50% and monitor closely
Dose cautiously in patients with history of MI or CHF
When switching from another antiarrhythmic to flecainide, allow >2-4 plasma half-lives to elapse before starting flecainide; if discontinuation of previous drug may produce life-threatening arrhythmias, consider hospitalizing patient
Dosage Modifications
Renal impairment
- Severe (<35 mL/min): 100 mg PO qDay or 50 mg PO BID
- >25 mL/min: 100 mg PO BID
Hepatic impairment
- Use only if benefits outweigh risk; monitor plasma levels regularly; reduce dose as necessary
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (3)
- nirmatrelvir
nirmatrelvir will increase the level or effect of flecainide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Nirmatrelvir/ritonavir is contraindicated with drugs that are highly dependent on CYP3A for clearance and for which elevated concentrations are associated with serious and/or life-threatening reactions.
- nirmatrelvir/ritonavir
nirmatrelvir/ritonavir will increase the level or effect of flecainide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Nirmatrelvir/ritonavir is contraindicated with drugs that are highly dependent on CYP3A for clearance and for which elevated concentrations are associated with serious and/or life-threatening reactions.
- tipranavir
tipranavir will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated. Coadministration may result in flecainide-induced QT prolongation
Serious - Use Alternative (62)
- alfuzosin
alfuzosin and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- amisulpride
amisulpride and flecainide both increase QTc interval. Avoid or Use Alternate Drug. ECG monitoring is recommended if coadministered.
- aripiprazole
aripiprazole and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- arsenic trioxide
arsenic trioxide and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- artemether
artemether and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- artemether/lumefantrine
artemether/lumefantrine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.
- atomoxetine
atomoxetine and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- ceritinib
ceritinib and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- clozapine
clozapine and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- dacomitinib
dacomitinib will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid use with CYP2D6 substrates where minimal increases in concentration of the CYP2D6 substrate may lead to serious or life-threatening toxicities.
- degarelix
degarelix and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- desflurane
desflurane and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- deutetrabenazine
deutetrabenazine and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- digoxin
flecainide increases effects of digoxin by unknown mechanism. Avoid or Use Alternate Drug.
- disopyramide
disopyramide and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- dofetilide
dofetilide and flecainide both increase QTc interval. Avoid or Use Alternate Drug. Additive cardiac effects.
- donepezil
donepezil and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- efavirenz
efavirenz and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- encorafenib
encorafenib and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- entrectinib
flecainide and entrectinib both increase QTc interval. Avoid or Use Alternate Drug.
- eribulin
eribulin and flecainide both increase QTc interval. Avoid or Use Alternate Drug. Potential for enhanced QTc-prolonging effects; if concurrent use is necessary then ECG monitoring is recommended.
- escitalopram
escitalopram increases toxicity of flecainide by QTc interval. Avoid or Use Alternate Drug.
- fexinidazole
fexinidazole and flecainide both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels or prolong QT interval.
- fingolimod
fingolimod and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- fluoxetine
fluoxetine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.
- gadobenate
gadobenate and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- gemifloxacin
gemifloxacin and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- gilteritinib
gilteritinib and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- givosiran
givosiran will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP2D6 substrates with givosiran. If unavoidable, decrease the CYP2D6 substrate dosage in accordance with approved product labeling.
- glasdegib
flecainide and glasdegib both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, monitor for increased risk of QTc interval prolongation.
- granisetron
granisetron and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- hydroxychloroquine sulfate
hydroxychloroquine sulfate and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- hydroxyzine
hydroxyzine and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- ibutilide
flecainide and ibutilide both increase QTc interval. Avoid or Use Alternate Drug.
- indapamide
flecainide and indapamide both increase QTc interval. Avoid or Use Alternate Drug.
- inotuzumab
inotuzumab and flecainide both increase QTc interval. Avoid or Use Alternate Drug. If unable to avoid concomitant use, obtain ECGs and electrolytes before and after initiation of any drug known to prolong QTc, and periodically monitor as clinically indicated during treatment.
- isoflurane
isoflurane and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- ivosidenib
ivosidenib and flecainide both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of QTc prolonging drugs with ivosidenib or replace with alternate therapies. If coadministration of a QTc prolonging drug is unavoidable, monitor for increased risk of QTc interval prolongation.
- lefamulin
lefamulin and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- lithium
lithium and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- lumefantrine
lumefantrine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.
- macimorelin
macimorelin and flecainide both increase QTc interval. Avoid or Use Alternate Drug. Macimorelin causes an increase of ~11 msec in the corrected QT interval. Avoid coadministration with drugs that prolong QT interval, which could increase risk for developing torsade de pointes-type ventricular tachycardia. Allow sufficient washout time of drugs that are known to prolong the QT interval before administering macimorelin.
- mirtazapine
mirtazapine and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- mobocertinib
mobocertinib and flecainide both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, reduce mobocertinib dose and monitor QTc interval more frequently.
- ondansetron
flecainide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.
- panobinostat
flecainide and panobinostat both increase QTc interval. Avoid or Use Alternate Drug. Panobinostat is known to significantly prolong QT interval. Panobinostat prescribing information states use with drugs known to prolong QTc is not recommended.
- paroxetine
paroxetine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.
- pentamidine
flecainide and pentamidine both increase QTc interval. Avoid or Use Alternate Drug.
- pimozide
flecainide and pimozide both increase QTc interval. Avoid or Use Alternate Drug.
- pitolisant
flecainide and pitolisant both increase QTc interval. Avoid or Use Alternate Drug.
- ponesimod
ponesimod, flecainide. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Consult cardiologist if considering treatment. Coadministration of ponesimod with drugs that decrease HR may have additive effects on decreasing HR and should generally not be initiated in these patients.
- procainamide
flecainide and procainamide both increase QTc interval. Avoid or Use Alternate Drug.
- quinidine
quinidine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.
quinidine and flecainide both increase QTc interval. Avoid or Use Alternate Drug. - ribociclib
ribociclib increases toxicity of flecainide by QTc interval. Avoid or Use Alternate Drug.
- ritonavir
ritonavir will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated. Concurrent use of flecainide and ritonavir is contraindicated.
ritonavir increases levels of flecainide by decreasing metabolism. Contraindicated. - romidepsin
flecainide and romidepsin both increase QTc interval. Avoid or Use Alternate Drug.
- sevoflurane
sevoflurane and flecainide both increase QTc interval. Avoid or Use Alternate Drug.
- sotalol
flecainide and sotalol both increase QTc interval. Avoid or Use Alternate Drug.
- umeclidinium bromide/vilanterol inhaled
flecainide increases toxicity of umeclidinium bromide/vilanterol inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.
- vandetanib
flecainide, vandetanib. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Avoid coadministration with drugs known to prolong QT interval; if a drug known to prolong QT interval must be used, more frequent ECG monitoring is recommended.
- vemurafenib
vemurafenib increases levels of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Concomitant use of vemurafenib with agents with narrow therapeutic windows is not recommended as vemurafenib may alter their concentrations. If coadministration cannot be avoided, use caution and consider dose reduction of concomitant CYP2D6 substrate drug. Combination may increase risk QT prolongation.
- vilanterol/fluticasone furoate inhaled
flecainide increases toxicity of vilanterol/fluticasone furoate inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.
Monitor Closely (132)
- abiraterone
abiraterone increases levels of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Avoid coadministration of abiraterone with substrates of CYP2D6. If alternative therapy cannot be used, exercise caution and consider a dose reduction of the CYP2D6 substrate.
- acetazolamide
acetazolamide will increase the level or effect of flecainide by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- albuterol
albuterol and flecainide both increase QTc interval. Use Caution/Monitor.
- aluminum hydroxide
aluminum hydroxide will increase the level or effect of flecainide by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- amiodarone
amiodarone and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- amitriptyline
amitriptyline and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- amoxapine
amoxapine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- arformoterol
arformoterol and flecainide both increase QTc interval. Use Caution/Monitor.
- artemether/lumefantrine
flecainide and artemether/lumefantrine both increase QTc interval. Modify Therapy/Monitor Closely.
- asenapine
asenapine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- bedaquiline
flecainide and bedaquiline both increase QTc interval. Modify Therapy/Monitor Closely. ECG should be monitored closely
- bupropion
bupropion will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Coadministration of bupropion and flecainide should be approached with caution and should be initiated at the lower end of the dose range of flecainide. If bupropion is added to the treatment regimen of a patient already receiving flecainide, consider decreasing the dose of flecainide.
- calcium carbonate
calcium carbonate will increase the level or effect of flecainide by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- celecoxib
celecoxib will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- chloroquine
chloroquine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
chloroquine increases toxicity of flecainide by QTc interval. Use Caution/Monitor. - chlorpromazine
chlorpromazine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- cimetidine
cimetidine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Flecainide dosage should be carefully titrated on initiation of therapy. Careful monitoring of flecainide plasma concentration should be instituted when cimetidine is coadministered or discontinued.
- ciprofloxacin
ciprofloxacin and flecainide both increase QTc interval. Use Caution/Monitor. Ciprofloxacin elicits minimal effects on QT interval. Caution if used in combination with other drugs known to affect QT interval or in patients with other risk factors.
- citalopram
flecainide and citalopram both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended, along with drugs that may prolong the QT interval.
- clarithromycin
clarithromycin and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- clobazam
clobazam will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Lower doses of drugs metabolized by CYP2D6 may be required when used concomitantly.
- clomipramine
clomipramine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- cobicistat
cobicistat will increase the level or effect of flecainide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Clinical monitoring is recommended upon coadministration with antiarrhythmics.
- crizotinib
crizotinib and flecainide both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended, along with drugs that may prolong the QT interval.
- darifenacin
darifenacin will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- darunavir
darunavir will increase the level or effect of flecainide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Clinical monitoring is recommended upon coadministration with antiarrhythmics.
- dasatinib
dasatinib and flecainide both increase QTc interval. Use Caution/Monitor.
- desipramine
desipramine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- desvenlafaxine
desvenlafaxine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Desvenlafaxine inhibits CYP2D6; with higher desvenlafaxine doses (ie, 400 mg) decrease the CYP2D6 substrate dose by up to 50%; no dosage adjustment needed with desvenlafaxine doses <100 mg
- diphenhydramine
diphenhydramine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- dolasetron
dolasetron and flecainide both increase QTc interval. Use Caution/Monitor.
- doxepin
doxepin and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- dronedarone
dronedarone will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
dronedarone and flecainide both increase QTc interval. Modify Therapy/Monitor Closely. - droperidol
droperidol and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- eliglustat
eliglustat increases levels of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the concomitant drug and titrate to clinical effect.
- elvitegravir/cobicistat/emtricitabine/tenofovir DF
elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP2D6 inhibitor; caution with CYP2D6 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.
- epinephrine
epinephrine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- epinephrine racemic
epinephrine racemic and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- erythromycin base
erythromycin base and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- erythromycin ethylsuccinate
erythromycin ethylsuccinate and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- erythromycin lactobionate
erythromycin lactobionate and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- erythromycin stearate
erythromycin stearate and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- ezogabine
ezogabine, flecainide. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Slight and transient QT-prolongation observed with ezogabine, particularly when dose titrated to 1200 mg/day. QT interval should be monitored when ezogabine is prescribed with agents known to increase QT interval.
- fedratinib
fedratinib will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.
- fluconazole
flecainide and fluconazole both increase QTc interval. Modify Therapy/Monitor Closely.
- fluoxetine
flecainide and fluoxetine both increase QTc interval. Use Caution/Monitor.
- fluphenazine
fluphenazine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- fluvoxamine
fluvoxamine and flecainide both increase QTc interval. Use Caution/Monitor.
- formoterol
flecainide and formoterol both increase QTc interval. Modify Therapy/Monitor Closely.
- foscarnet
flecainide and foscarnet both increase QTc interval. Use Caution/Monitor.
- fostemsavir
flecainide and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- gemtuzumab
flecainide and gemtuzumab both increase QTc interval. Use Caution/Monitor.
- goserelin
goserelin increases toxicity of flecainide by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.
- haloperidol
haloperidol will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. If concurrent use cannot be avoided, cautious dosing and telemetric monitoring is advised.
flecainide and haloperidol both increase QTc interval. Modify Therapy/Monitor Closely. - hawthorn
hawthorn increases effects of flecainide by pharmacodynamic synergism. Use Caution/Monitor.
- histrelin
histrelin increases toxicity of flecainide by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.
- iloperidone
flecainide and iloperidone both increase QTc interval. Use Caution/Monitor.
- imatinib
imatinib will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- imipramine
imipramine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- indacaterol, inhaled
indacaterol, inhaled, flecainide. QTc interval. Use Caution/Monitor. Drugs that are known to prolong the QTc interval may have an increased the risk of ventricular arrhythmias.
- itraconazole
flecainide and itraconazole both increase QTc interval. Modify Therapy/Monitor Closely.
- ketoconazole
flecainide and ketoconazole both increase QTc interval. Modify Therapy/Monitor Closely.
- lapatinib
flecainide and lapatinib both increase QTc interval. Use Caution/Monitor.
- lenvatinib
flecainide and lenvatinib both increase QTc interval. Use Caution/Monitor. Lenvatinib prescribing information recommends monitoring ECG closely when coadministered with QT prolonging drugs.
- leuprolide
leuprolide increases toxicity of flecainide by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.
- levofloxacin
flecainide and levofloxacin both increase QTc interval. Use Caution/Monitor.
- levoketoconazole
flecainide and levoketoconazole both increase QTc interval. Modify Therapy/Monitor Closely.
- lofepramine
lofepramine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- lorcaserin
lorcaserin will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- lumefantrine
flecainide and lumefantrine both increase QTc interval. Modify Therapy/Monitor Closely.
- maprotiline
maprotiline and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- maraviroc
maraviroc will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- marijuana
marijuana will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- methadone
flecainide and methadone both increase QTc interval. Use Caution/Monitor.
- mifepristone
mifepristone, flecainide. QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available.
- mirabegron
mirabegron will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- moxifloxacin
flecainide and moxifloxacin both increase QTc interval. Modify Therapy/Monitor Closely.
- nilotinib
nilotinib will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
flecainide and nilotinib both increase QTc interval. Modify Therapy/Monitor Closely. - nortriptyline
nortriptyline and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- octreotide
flecainide and octreotide both increase QTc interval. Modify Therapy/Monitor Closely.
- octreotide (Antidote)
flecainide and octreotide (Antidote) both increase QTc interval. Modify Therapy/Monitor Closely.
- ofloxacin
flecainide and ofloxacin both increase QTc interval. Use Caution/Monitor.
- olanzapine
olanzapine and flecainide both increase QTc interval. Use Caution/Monitor.
- olodaterol inhaled
flecainide and olodaterol inhaled both increase QTc interval. Use Caution/Monitor. Drugs that prolong the QTc interval and may potentiate the effects of beta2 agonists on the cardiovascular system; increased risk of ventricular arrhythmias
- ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC)
ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) will increase the level or effect of flecainide by decreasing metabolism. Modify Therapy/Monitor Closely. Caution is warranted and therapeutic concentration monitoring (if available) is recommended for antiarrhythmics when coadministered with Viekira Pak
- oritavancin
oritavancin will decrease the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Oritavancin is a weak CYP2D6 inducer; caution if coadministered with CYP2D6 substrates that have a narrow therapeutic index
- osilodrostat
osilodrostat and flecainide both increase QTc interval. Use Caution/Monitor.
- osimertinib
osimertinib and flecainide both increase QTc interval. Use Caution/Monitor. Conduct periodic monitoring with ECGs and electrolytes in patients taking drugs known to prolong the QTc interval.
- oxaliplatin
oxaliplatin will increase the level or effect of flecainide by Other (see comment). Use Caution/Monitor. Monitor for ECG changes if therapy is initiated in patients with drugs known to prolong QT interval.
- ozanimod
ozanimod and flecainide both increase QTc interval. Modify Therapy/Monitor Closely. The potential additive effects on heart rate, treatment with ozanimod should generally not be initiated in patients who are concurrently treated with QT prolonging drugs with known arrhythmogenic properties.
- paliperidone
flecainide and paliperidone both increase QTc interval. Use Caution/Monitor.
- parecoxib
parecoxib will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- paroxetine
flecainide and paroxetine both increase QTc interval. Use Caution/Monitor.
- pasireotide
flecainide and pasireotide both increase QTc interval. Modify Therapy/Monitor Closely.
- peginterferon alfa 2b
peginterferon alfa 2b, flecainide. Other (see comment). Use Caution/Monitor. Comment: When patients are administered peginterferon alpha-2b with CYP2D6 substrates, the therapeutic effect of these drugs may be altered. Peginterferon alpha-2b may increase or decrease levels of CYP2D6 substrate.
- perphenazine
perphenazine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
perphenazine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely. - posaconazole
flecainide and posaconazole both increase QTc interval. Use Caution/Monitor.
- prochlorperazine
prochlorperazine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- promazine
promazine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- promethazine
promethazine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- propafenone
propafenone will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- propranolol
flecainide, propranolol. Either increases levels of the other by decreasing metabolism. Use Caution/Monitor. Increased serum levels of both agents; additive negative inotropic effects.
- protriptyline
protriptyline and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- quetiapine
quetiapine, flecainide. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.
- quinacrine
quinacrine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- quinine
flecainide and quinine both increase QTc interval. Use Caution/Monitor.
- ranolazine
ranolazine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
flecainide and ranolazine both increase QTc interval. Use Caution/Monitor. - rilpivirine
rilpivirine increases toxicity of flecainide by QTc interval. Use Caution/Monitor. Rilpivirine should be used with caution when co-administered with a drug with a known risk of Torsades de Pointes.
- risperidone
flecainide and risperidone both increase QTc interval. Use Caution/Monitor.
- rolapitant
rolapitant will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Rolapitant may increase plasma concentrations of CYP2D6 substrates for at least 28 days following rolapitant administration.
- saquinavir
saquinavir increases levels of flecainide by QTc interval. Modify Therapy/Monitor Closely. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.
- selpercatinib
selpercatinib increases toxicity of flecainide by QTc interval. Use Caution/Monitor.
- sevelamer
sevelamer decreases levels of flecainide by increasing elimination. Use Caution/Monitor.
- sodium bicarbonate
sodium bicarbonate will increase the level or effect of flecainide by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- sodium citrate/citric acid
sodium citrate/citric acid will increase the level or effect of flecainide by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- sodium lactate
sodium lactate will increase the level or effect of flecainide by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- sorafenib
sorafenib and flecainide both increase QTc interval. Use Caution/Monitor.
- sulfamethoxazole
sulfamethoxazole and flecainide both increase QTc interval. Use Caution/Monitor.
- teduglutide
teduglutide increases levels of flecainide by Other (see comment). Use Caution/Monitor. Comment: Teduglutide may increase absorption of concomitant PO medications; caution with with drugs requiring titration or those with a narrow therapeutic index; dose adjustment may be necessary.
- telavancin
flecainide and telavancin both increase QTc interval. Use Caution/Monitor.
- terbinafine
terbinafine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Assess need to reduce dose of CYP2D6-metabolized drug.
- thioridazine
thioridazine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
thioridazine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely. - trazodone
trazodone and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- trifluoperazine
trifluoperazine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- trimethoprim
flecainide and trimethoprim both increase QTc interval. Use Caution/Monitor.
- trimipramine
trimipramine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.
- triptorelin
triptorelin increases toxicity of flecainide by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.
- tropisetron
flecainide and tropisetron both increase QTc interval. Use Caution/Monitor.
- venlafaxine
venlafaxine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
flecainide and venlafaxine both increase QTc interval. Use Caution/Monitor. - voclosporin
voclosporin, flecainide. Either increases effects of the other by QTc interval. Use Caution/Monitor.
- voriconazole
flecainide and voriconazole both increase QTc interval. Use Caution/Monitor.
- ziprasidone
flecainide and ziprasidone both increase QTc interval. Modify Therapy/Monitor Closely.
Minor (6)
- apomorphine
apomorphine and flecainide both increase QTc interval. Minor/Significance Unknown.
- azithromycin
azithromycin and flecainide both increase QTc interval. Minor/Significance Unknown.
- duloxetine
duloxetine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- lily of the valley
flecainide, lily of the valley. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown.
- pazopanib
flecainide and pazopanib both increase QTc interval. Minor/Significance Unknown.
- sertraline
sertraline will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown. Monitor the EKG in patients receiving concurrent flecainide and sertraline. Doses of flecainide may need to be reduced.
Adverse Effects
>10%
Visual disturbances (5-16%)
Dizziness (10-19%)
1-10%
Arrhythmias
Edema (1-4%)
Asthenia (2-5%)
Palpitations (2-7%)
Fatigue (3-8%)
Tremors (2-5%)
Constipation (1-4%)
Nausea (5-9%)
Chest pain (1-5%)
Dyspnea (5-10%)
Headache (5-10%)
Abdominal pain (1-3%)
Malaise (1-3%)
Fever (1-3%)
Tachycardia (1-3%)
Sinus pause/arrest (1-3%)
Vomiting (1-3%)
Diarrhea (1-3%)
Dyspepsia (1-3%)
Anorexia (1-3%)
Rash (1-3%)
Diplopia (1-3%)
Hypoesthesia (1-3%)
Paresthesia (1-3%)
Paresis (1-3%)
Ataxia (1-3%)
Flushing (1-3%)
Diaphoresis (1-3%)
Vertigo (1-3%)
Syncope (1-3%)
Somnolence (1-3%)
Tinnitus (1-3%)
Anxiety (1-3%)
Insomnia (1-3%)
Depression (1-3%)
Warnings
Black Box Warnings
Mortality
- NHLBI’s Cardiac Arrhythmia Suppression Trial (CAST): Excessive mortality or nonfatal cardiac arrest (7.7%) shown with encainide or flecainide, compared with placebo (3%)
- This was a long-term, multicenter, randomized, double-blind study in patients with asymptomatic, non-life-threatening ventricular arrhythmias who previously had MI >6 days but <2 yr
- Average duration of treatment with encainide or flecainide was 10 months
- Applicability of results to other populations is uncertain
- Reserve class IC antiarrhythmics use for life-threatening ventricular arrhythmias only
- Due to known proarrhythmic properties of flecainide and lack of evidence of improved survival for any antiarrhythmics, flecainide use should be restricted to patients with life-threatening ventricular arrhythmias
Ventricular proarrhythmic effects with AF/flutter
- Not recommended for chronic atrial fibrillation
- 10.5% incidence of ventricular tachycardia/fibrillation in patients treated for chronic atrial fibrillation
- Proarrhythmic effects with flecainide for atrial fibrillation/flutter: Increased risk of PVCs, ventricular tachycardia, ventricular fibrillation, and fatality
- As with other class I agents, use of flecainide for atrial flutter has been reported with 1:1 atrioventricular conduction due to atrial rate slowing
- Paradoxical increase in ventricular rate may occur in patients with atrial fibrillation; concomitant negative chronotropic therapy (eg, digoxin, beta blockers) may lower risk
Contraindications
Hypersensitivity
2nd or 3rd degree AV block, right bundle branch block when associated with left hemiblock (bifascicular block), unless pacemaker is present to sustain cardiac rhythm; discontinue therapy immediately
Cautions
Atrial fibrillation, CHF, hypotension, HTN, post MI patients, geriatrics, proarrhythmia events, hepatic/renal impairment, sick sinus syndrome
May slow cardiac conduction to produce dose-related increases in PR, QRS, and QT intervals; manage patient on lowest effective dose
Discontinuation should be done in hospital
Causes increased mortality in post-AMI period, also with chronic atrial fibrillation
May affect endocardial pacemaker reversibly by increasing endocardial pacing thresholds or suppressing ventricular escape rhythms; do not administer to patients with existing poor thresholds or nonprogrammable pacemakers unless suitable pacing rescue is available
Correct electrolyte imbalances, especially hypomagnesemia or hypokalemia before initiating therapy
May cause visual disturbances
Flecainide may depress LV function significantly with preexisting LV dysfunction
Flecainide should be avoided in patients with HF or structural heart disease
Pregnancy & Lactation
Pregnancy category: C
Lactation: Enters breast milk
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
Class IC antidysrhythmic; slows conduction in cardiac tissue by altering transport of ion across membranes; causes slight prolongation of refractory periods, decreases rate of rise of action potential without affecting its duration; local anesthetic and moderate negative inotropic effects
Absorption
Bioavailability: 85-90%
Peak plasma time: 2-3 hr (PO)
Therapeutic range: 0.2-1 mcg/mL
Toxicity range: >0.7-1 mcg/mL
Distribution
Protein bound: 40-50%
Vd: 5.5-8.7 L/kg
Metabolism
Undergoes extensive biotransformation to 2 major and several minor metabolites; subject to genetic polymorphism; R-enantiomer is metabolized by hepatic CYP2D6
Metabolites: Meta-O-dealkylated flecainide, meta-O-dealkylated lactam of flecainide (inactive)
Elimination
Half-life: 12 to 27hr; t1/2 increased in renal impairment
Dialyzable: Yes (HD)
Total plasma clearance: 10 mL/min/kg
Note: Elimination is much slower with highly alkaline urine (pH >8), which may occur in rare conditions (eg, renal tubular acidosis, strict vegetarian diet)
Excretion: Urine (80-90%); feces (minor)
Administration
Oral Administration
May take with food
Images
| BRAND | FORM. | UNIT PRICE | PILL IMAGE |
|---|---|---|---|
| flecainide oral - | 150 mg tablet |  | |
| flecainide oral - | 50 mg tablet |  | |
| flecainide oral - | 100 mg tablet |  | |
| flecainide oral - | 50 mg tablet |  | |
| flecainide oral - | 150 mg tablet |  | |
| flecainide oral - | 100 mg tablet |  | |
| flecainide oral - | 150 mg tablet |  | |
| flecainide oral - | 100 mg tablet |  | |
| flecainide oral - | 50 mg tablet |  | |
| flecainide oral - | 150 mg tablet |  | |
| flecainide oral - | 100 mg tablet |  | |
| flecainide oral - | 50 mg tablet |  |
Copyright © 2010 First DataBank, Inc.
Patient Handout
flecainide oral
FLECAINIDE - ORAL
(fleck-UH-nide)
COMMON BRAND NAME(S): Tambocor
WARNING: Though this medication often gives great benefits to people with irregular heartbeat, it may rarely cause a serious new irregular heartbeat. When starting treatment with this drug, your doctor may recommend that you stay in the hospital for proper monitoring. Flecainide should not be used to treat a certain type of irregular heartbeat (persistent atrial fibrillation/flutter). Talk with your doctor about the benefits and risks of taking this medication for your condition.
USES: This medication is used to treat certain types of serious (possibly fatal) irregular heartbeat (such as sustained ventricular tachycardia and paroxysmal supraventricular tachycardia). It is used to restore normal heart rhythm and maintain a regular, steady heartbeat. It is also used to prevent certain types of irregular heartbeat from returning (such as atrial fibrillation). Flecainide is known as an anti-arrhythmic drug. It works by blocking certain electrical signals in the heart that can cause an irregular heartbeat. Treating an irregular heartbeat can decrease the risk for blood clots, and this effect can reduce your risk of heart attack or stroke.Older adults should discuss the risks and benefits of this medication with their doctor or pharmacist, as well as other effective and possibly safer treatments.
HOW TO USE: Take this medication by mouth with or without food, usually twice daily or as directed by your doctor.The dosage is based on your age, medical condition, response to treatment, and other medications you may be taking. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day.Tell your doctor if your condition does not improve or if it worsens.
SIDE EFFECTS: See also Warning section.Dizziness, vision problems (such as blurred vision, problems focusing, seeing spots), headache, nausea, shaking, tiredness, or weakness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.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: new or worsening symptoms of heart failure (such as shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain).Get medical help right away if you have any very serious side effects, including: faster/more irregular heartbeat, severe dizziness, fainting.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 flecainide, 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: kidney problems, liver problems, other heart problems (such as previous heart attack, heart pacemaker).This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).Flecainide may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using flecainide, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using flecainide safely.Older adults may be more sensitive to the side effects of this drug, especially QT prolongation (see above).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. However, this drug is unlikely to harm a nursing infant. 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.Many drugs besides flecainide may affect the heart rhythm (QT prolongation), including amiodarone, dofetilide, pimozide, procainamide, quinidine, sotalol, and macrolide antibiotics (such as erythromycin), among others.Other medications can affect the removal of flecainide from your body, which may affect how flecainide works. Examples include asunaprevir, cimetidine, fluconazole, certain HIV protease inhibitors (such as ritonavir, tipranavir), anti-seizure drugs (such as phenytoin, phenobarbital), 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. Symptoms of overdose may include: severe nausea/vomiting, seizures, very slow heartbeat, severe dizziness, fainting.
NOTES: Do not share this medication with others.Laboratory and/or medical tests (such as EKG) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.
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 February 2022. Copyright(c) 2022 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
Adding plans allows you to compare formulary status to other drugs in the same class.
To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.
Adding plans allows you to:
- View the formulary and any restrictions for each plan.
- Manage and view all your plans together – even plans in different states.
- Compare formulary status to other drugs in the same class.
- Access your plan list on any device – mobile or desktop.
