Flecainide interactions

Drugs that may interact include chlorpropamide, lithium, methotrexate, salicylates, tetracyclines, anorexiants, flecainide, mecamylamide, quinidine, and sympathomimetics. 

Drugs that may affect amiodarone include hydantoins, cholestyramine, fluoroquinolones, rifamycins, ritonavir, and cimetidine. Drugs that may be affected by amiodarone include anticoagulants, beta-blockers, calcium channel blockers, cyclosporine, dextromethorphan, digoxin, disopyramide, fentanyl, flecainide, hydantoins, lidocaine, methotrexate, procainamide, quinidine, and theophylline. Drug/Lab test interactions Amiodarone alters the results of thyroid function tests, causing an increase in serum T4 and serum reverse T3 levels and a decline in... 

Fosamprenavir plus ritonavir may interact with flecainide, propafenone, efavirenz plus ritonavir, and lopinavir plus ritonavir. Efavirenz may affect fosamprenavir with or without ritonavir. 

WARNING Co administration w/ ritonavir assoc w/ Hep hepatic decomp w/ fatalities. D/C w/ S/Sxs of H Uses HIV 1 Infxn w/ highly Tx-experienced pts or HIV 1 strains resistant to multiple protease inhibitors. Must be used w/ ritonavir 200 mg Action Antiretroviral HIV-1 protease inhibitor Dose 500 mg PO bid w/ food, administer w/ ritonavir 200 mg PO bid Caution [C, -] Sulfa aU gy, Uvct Dz Contra Mod-severe hepatic insuff concomitant use w/ amiodarone, astemizole, bepridil, cisapride, ergots, flecainide, lovastatin, midazolam, pimozide, propafenone, quinidine, rifampin, simvastatin, terfenadine, triazolam, St. John s wort Disp Caps SE HA, GI distress, rash, fati e, fat redistribution, hyperglycemia, Hep, liver Dz, lipid elevations Interactions T Effects OF anticoagulants, antipits, azole antifun-... 

Drug Interactions Other antihypertensive agents Carbamazepine (vasodilators, ACE inhibitors, Rifampin diuretics, and beta-blockers) Phenobarbital Digoxin Cyclosporine Disopyramide Theophylline Flecainide Inhalation anesthetics Quinidine Neuromuscular blocking agents Cimetidine Lithium ... 

Secondary> hyperparathyroidism 30 mg PO daily Parathyroid carcinoma 30 mg PO bid titrate q2—4wk based on Ca PTH levels swallow whole take w/ food Caution [C, /—] w/ Szs Disp Tabs SE N/V/D, myalgia, dizziness, 4- Ca2+ Interactions T Effects W/ CYP3A4 inhibitors such as ketoconazole, itraconazole, erythromycin T effects OF drugs metabolized at CYP2D6 such as TCA, thioridazine, flecainide, vinblastine EMS Monitor ECG for signs of hypocalcemia (T QT interval) OD May cause severe hypocalcemia calcium salts can be given... 

Lopinavir/Ritonavir (Kaletra) [Anrirelroviral/Protease Inhibitor] Uses HIV Infxn Action Protease inhibitor Dose Adults. Tx naive 2 tab PO daily or 1 tab PO bid Tx experiencedpt 1 tab PO bid (T dose if w/ amprenavir, efavirenz, fosamprenavir, nelfinavir, nevirapine) Peds. 7-15 kg 12/3 mg/kg PO bid 15-40 kg 10/2.5 mg/kg PO bid >40 kg Adult dose w/ food Caution [C, /-] Numerous interactions Contra w/drugs dependent on CYP3A/CYP2D6 (Table VI-8) Disp Tab, soln SE Avoid disulfiram (soln has EtOH), metronidazole GI upset, asthenia, T cholesterol/triglycerides, pancreatitis protease metabolic synd Interactions T Effects Wl clarithromycin, erythromycin T effects OF amiodarone, amprenavir, azole andfungals, bepridil, cisapride, cyclosporine, CCBs, ergot alkaloids, flecainide, flurazepam, HMG-CoA reductase inhibitors, indinavir, lidocaine, meperidine, midazolam, pimozide, propafenone, propoxyphene, quinidine, rifabutin, saquinavir, sildenafil, tacrolimus, terfenadine, triazolam, zolpidem 1 effects Wl barbiturates, carbamazepine, dexamethasone, didanosine, efavirenz, nevirapine, phenytoin, rifabutin, rifampin, St. John s wort 1 effects OF OCPs, warfarin EMS Use andarrhythmics and benzodiazepines... 

The results showed that mortality among patients treated with the drugs flecainide and encainide (the latter is no longer available) was increased more than twofold compared with those treated with placebo. The mechanism underlying this effect is not known, although an interaction between conduction depression by sodium channel block and chronic or acute myocardial ischemia seems likely. Indirect evidence suggests that other sodium channel blockers may produce a similar effect. 

The calcium channel blocker mibefradil (Posicor ) was removed from the market in 1998. The headline for the Pink Sheets article describing this action was "Posicor Withdrawal Reflects Complexity of Interaction Profile" (59). Products identified as potentially dangerous in combination with mibefradil included cardiac drugs, such as amiodarone, flecainide, and propafenone oncologic products, such as tamoxifen, cyclophosphamide, etoposide, ifosfamide, and vinblastine and the immunosuppressant medications cyclosporine and tacrolimus. The sponsor s decision to withdraw mibefradil was based on the complexity of the drug interaction information that would have to be communicated to ensure safe usage. 

Adenosine does not interact with digoxin, disopyramide, flecainide, or quinidine. 

Lewis GP, Holtzman JL. Interaction of flecainide with digoxin and propranolol. Am J Cardiol 1984 53(5) B52-7. 

Although verapamil reduces the clearance of flecainide, this is probably not clinically important (76). However, there is also a pharmacodjmamic interaction, since both drugs increase the PR interval and have additive effects on myocardial contractihty and atrioventricular conduction (77). 

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