Erythromycin Beta blockers

Codeine, dextromethorphan, haloperidol, thioridazine, perphenazine, nortriptyline, desipramine, fluoxetine, norfluoxetine, TCAs (hydroxylation), beta-blockers such as timolol and metoprolol, type 1C antiarrhythmics encainide, flecainide TCAs (desmethylation), triazolam, alprazolam, midazolam, carbamazepine, terfenadine, quinidine, lidocaine, erythromycin, cyclosporin... 

Drugs that may affect repaglinide include CYP 450 inhibitors (eg, clarithromycin, erythromycin, ketoconazole, miconazole), CYP 450 inducers (eg, barbiturates, carbamazepine, rifampin), beta blockers, calcium channel blockers, chloramphenicol, corticosteroids, coumarins, estrogens, gemfibrozil, isoniazid, itraconazole, levonorgestrel and ethinyl estradiol, MAOIs, nicotinic acid, NSAIDs, oral contraceptives, phenothiazines, phenytoin, probenecid, salicylates, simvastatin, sulfonamides, sympathomimetics, thiazides and other diuretics, and thyroid products. 

Drugs that may affect disopyramide include antiarrhythmics, beta blockers, cisapride, clarithromycin, erythromycin, fluoroquinolones, hydantoins, quinidine, thioridazine, rifampin, verapamil, and ziprasidone. Drugs that may be affected by disopyramide include quinidine, anticoagulants, and digoxin. 

Drugs that may affect antihistamines include aluminum/magnesium-containing acids, cimetidine, erythromycin, ketoconazole, MAO inhibitors, and rifamycins (eg, rifampin). Drugs that may be affected by antihistamines include alcohol and CNS depressants, beta-blockers, MAO inhibitors, metyrapone, nefazodone, selective serotonin reuptake inhibitors (SSRIs), and venlafaxine. 

Drugs that may affect penicillins include allopurinol, aminoglycosides (parenteral), aspirin, beta blockers, chloramphenicol, erythromycin, ethacrynic acid, furosemide, indomethacin, phenylbutazone, probenecid, sulfonamides, tetracycline, and thiazide diuretics. Drugs that may be affected by penicillins include aminoglycosides (parenteral), anticoagulants, beta blockers, chloramphenicol, cyclosporine, oral contraceptives, erythromycin, heparin, and vecuronium. 

Ergot alkaloids interact with beta-blockers, antimigraine drugs, antibacterials, and glycerol nitrate. Concomitant administration with erythromycin causes ergotism.147,148... 

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... 

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). 

Clinically important, potentially hazardous interactions with amiodarone, beta-blockers, caspofungin, cyclosporine, dairy products, danazol, erythromycin, etoricoxib, grapefruit juice, hemophilus B vaccine, HMG-CoA reductase inhibitors, ibuprofen, immunosuppressants, ketoconazole, lopinavir, lovastatin, mycophenolate, peanuts, potassium, potassium-sparing diuretics, rifabutin, rifampin, rifapentine, simvastatin, St John s wort, telithromycin, vaccines... 

A study, in which 7 healthy subjects were given a single 80-mg dose of nadolol after erythromycin 500 mg plus neomycin 500 mg every 6 hours for 2 days, suggested an increase in the rate of beta blocker absorption (reduced time to maximum plasma level, but no effect on AUC). A decrease in the elimination half-life was also seen. More study is needed to determine the clinical significance of these findings. 

A patient who had marked hypotension and bradycardia when erythromycin was added to verapamil and propranolol (see under verapamil, below) had previously taken erythromycin with diltiazem and a beta blocker witiiout any reported adverse effects. ... 

When used concomitantly, theophylline increases the excretion of lithium. Also, cimetidine, allopurinol (high dose), propranolol, erythromycin, and troleandomycin may cause an increase in serum concentrations of theophylline by decreasing the hepatic clearance. Barbiturates and phenytoin enhance hepatic clearance and hepatic metabolism of theophylline, decreasing plasma levels. Beta-adrenergic blockers exert an antagonistic pharmacologic effect. 

---