Propafenone Beta blockers

PROPAFENONE BETA-BLOCKERS Risk of bradycardia (occasionally severe), 1 BP and heart failure Additive negative inotropic and chronotropic effects Monitor PR, BP and ECG closely watch for development of heart failure... 

PROPAFENONE I. ANTIARRHYTHMICS - disopyra-mide, procainamide 2. ANTIBIOTICS - macrolides (especially azithromycin, clarithromycin, parenteral erythromycin, telithromycin), quinolones (especially moxifloxacin), quinupristin/ dalfopristin 3. ANTICANCER AND IMMUNOMODULATING DRUGS -arsenic trioxide 4. ANTIDEPRESSANTS - TCAs, venlafaxine 5. ANTIEMETICS-dolasetron 6. ANTIFUNGALS-fluconazole, posaconazole, voriconazole 7. ANTIHISTAMINES - terfenadine, hydroxyzine, mizolastine 8. ANTI-M ALARIALS - artemether with lumefantrine, chloroquine, hydroxychloroquine, mefloquine, quinine 9. ANTIPROTOZOALS - pentamidine isetionate 10. ANTIPSYCHOTICS-atypicals, phenothiazines, pimozide II. BETA-BLOCKERS - sotalol 12. BRONCHODILATORS -parenteral bronchodilators 13. CNS STIMULANTS - atomoxetine Risk of ventricular arrhythmias, particularly torsades de pointes Additive effect these drugs prolong the Q-T interval. Also, amitriptyline, clomipramine and desipramine levels may be t by propafenone. Amitriptyline and clomipramine may t propafenone levels. Propafenone and these TCAs inhibit CYP2D6-mediated metabolism of each other Avoid co-administration... 

IMATINIB 1. ANTIARRHYTHMICS -flecainide, mexiletine, propafenone 2. ANTIDEPRESSANTS - fluoxetine, paroxetine, TCAs, trazodone, venlafaxine 3. ANTIPSYCHOTICS -clozapine, haloperidol, perphenazine, risperidone, thioridazine 4. BETA-BLOCKERS - metoprolol, propanolol, timolol 5. DONEPEZIL 6. METHAMPHETAMINE Imatinib may cause t plasma concentrations of these drugs, with a risk of toxic effects Inhibition of CYP2D6-mediated metabolism of these drugs Watch for early features of toxicity of these drugs... 

Mibefradil inhibits CYP3A4 (2). Other drugs that are metabolized by this pathway accumulate as a result. Drugs that were commonly affected included amiodarone, astemizole, ciclosporin, cisapride, erythromycin, imi-pramine, lovastatin, propafenone, quinidine, simvastatin (9), tacrohmus (10), tamoxifen, terfenadine, thioridazine, and drugs that impair sinoatrial node function (for example beta-blockers) (6). 

Information is limited but the interaetion would seem to be established. Concurrent use need not be avoided but antieipate the need to reduce the dosage of metoprolol and propranolol. Monitor closely because some patients may experience adverse effects. If the suggested mechanism of interaction is correct it is possible (but not confirmed) that other beta blockers that undergo liver metabolism will interact similarly but not those largely excreted unchanged in the urine. See Table 22.1 , (p.833) for the metabolism of some commonly used beta blockers. Also note that propafenone and the beta blockers have negative inotropic effects, which could be additive and result in unwanted cardiodepression. 

Selertive serotonin reuptake inhibitors may decrease metabolism of alpha/beta blockers, benzodiazepines, carbamazepine, cimetidine, clozapine, fesoterodine, haloperidol, methadone, mexiletine, phenytoin, propafenone, respiradone, tamoxifen, galantamine, respiradone, thioridazine. 

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