Methylprednisolone Erythromycin

Erythromycin metabolites can inhibit cytochrome P450 enzymes and thus increase the serum concentrations of numerous drugs, including theophylline, oral anticoagulants, cyclosporine, and methylprednisolone. Erythromycin increases serum concentrations of oral digoxin by increasing its bioavailability. 

Erythromycin Drugs that may be affected by erythromycin include alfentanil, anticoagulants, benzodiazepines, buspirone, carbamazepine, cisapride, cyclosporine, digoxin, disopyramide, ergot alkaloids, felodipine, fluoroquinolones, HMG-CoA reductase inhibitors, lincosamides, methylprednisolone, penicillins, and theophyllines. Drugs that may affect erythromycin include antacids, pimozide, rifamycins, and theophyllines. 

Drugs that may affect tacrolimus include nephrotoxic agents (aminoglycosides, amphotericin B, cisplatin, cyclosporine), antifungals, bromocriptine, calcium channel blockers, cimetidine, clarithromycin, danazol, diltiazem, erythromycin, methylprednisolone, metoclopramide, carbamazepine, phenobarbital, phenytoin, rifamycins, cisapride, chloramphenicol, metronidazole, nefazodone, omeprazole, protease inhibitors, macrolide antibiotics, fosphenytoin, and St. John s wort. 

Erythromycin inhibits a cytochrome P450 isoenzyme and impairs the metabolism of theophylline, warfarin, carbamazepine and methylprednisolone. The mean reduction in drug clearance is 20-25%. 

LaForce CF, Szefler SJ, Miller MF, EbUng W, Brenner M. Inhibition of methylprednisolone elimination in the presence of erythromycin therapy. J Allergy Qin Immunol 1983 72(l) 34-9. 

Clinically important, potentially hazardous interactions with adenosine, arformoterol, BCG vaccine, capsicum, carbimazole, cimetidine, ciprofloxacin, clorazepate, cocoa, erythromycin, eucalyptus, fluvoxamine, halothane, influenza vaccines, mebendazole, methylprednisolone, nilutamide, oral contraceptives, prednisolone, prednisone, rasagiline, raspberry leaf, roxithromycin, St John s wort, torasemide, torsemide... 

Clinically important, potentially hazardous interactions with acetylcysteine, adenosine, aprepitant, aripiprazole, buprenorphine, caffeine, charcoal, clarithromycin, clobazam, dorazepate, clozapine, darunavir, dasatinib, delavirdine, dexamethasone, diltiazem, doxacurium, erythromycin, felodipine, fesoterodine, fosamprenavir, imatinib, influenza vaccines, lacosamide, lapatinib, levetiracetam, lopinavir, methylprednisolone, midazolam, nelfinavir, nilotinib, piracetam, prednisolone, propoxyphene, ritonavir, rivaroxaban, rufinamide, solifenacin, St John s wort, telithromycin, temsirolimus, terbinafine, tolvaptan, troleandomycin, verapamil, voriconazole... 

Clinically important, potentially hazardous interactions with amiloride, aminoglycosides, amphotericin B, ampicillin, anisindione, anticoagulants, armodafinil, atorvastatin, azathioprine, azithromycin, bacampicillin, basiliximab, bezafibrate, bosentan, bupropion, carbenicillin, caspofungin, cholestyramine, clarithromycin, cloxacillin, co-trimoxazole, corticosteroids, cyclophosphamide, daclizumab, danazol, dicloxacillin, dicumarol, digoxin, diltiazem, disulfiram, echinacea, erythromycin, ethotoin, etoposide, ezetimibe, flunisolide, fluoxymesterone, fluvastatin, foscarnet, fosphenytoin, gemfibrozil, hemophilus B vaccine, HMG-CoA reductase inhibitors, imatinib, imipenem/cilastatin, influenza vaccines, ketoconazole, lanreotide, lopinavir, lovastatin, mephenytoin, methicillin, methoxsalen, methylphenidate, methylprednisolone, methyltestosterone, mezlocillin, mizolastine, mycophenolate, nafcillin, nisoldipine, NSAIDs, orlistat, oxacillin, penicillins, phellodendron, phenytoin, pravastatin, prednisolone, prednisone, pristinamycin, ranolazine, red rice yeast, rifabutin, rifampin, rifapentine, ritonavir, rosuvastatin, simvastatin, sirolimus, spironolactone, St John s wort, sulfacetamide, sulfadiazine, sulfamethoxazole, sulfisoxazole, sulfonamides, tacrolimus, telithromycin, tenoxicam, testosterone, ticarcillin, tolvaptan, trabectedin, triamterene, troleandomycin, ursodeoxycholic acid, vaccines, vecuronium, warfarin, zofenopril... 

Clinically important, potentially hazardous interactions with alfuzosin, alprazolam, amphotericin B, anisindione, antacids, aprepitant, astemizole, atorvastatin, bosentan, ciclesonide, cimetidine, clorazepate, conivaptan, cyproterone, dasatinib, dexamethasone, dicumarol, didanosine, eplerenone, erythromycin, ethotoin, fentanyl, fesoterodine, fosamprenavir, fosphenytoin, grapefruit juice, HMG-CoA reductase inhibitors, imatinib, ixabepilone, lapatinib, lopinavir, lovastatin, mephenytoin, methylprednisolone, micafungin, midazolam, nilotinib, pimozide, prednisolone, prednisone, quinidine, rifampin, rimonabant, rivaroxaban, sildenafil, silodosin, simvastatin, sirolimus, solifenacin, temsirolimus, terfenadine, tolvaptan, triazolam, vardenafil, vinblastine, vincristine, warfarin... 

Clinically important, potentially hazardous interactions with aprepitant, astemizole, carbamazepine, colchicine, cyclosporine, dihydroergotamine, ergot alkaloids, ergotamine, erythromycin, fluoxetine, fluvoxamine, methylprednisolone, methysergide, oral contraceptives, paroxetine, pimozide, prednisolone, rifampicin, sertraline, solifenacin, terfenadine, warfarin... 

Clarithromycin, danazol, diltiazem, erythromycin, fluconazole, fluvoxamine, grapefruit juice, itraconazole, ketoconazole, methylprednisolone, methyltestosterone, nicardipine, norethisterone, protease inhibitors, verapamil... 

Since erythromycin complexes and inactivates drug oxidizing systems such as cytochrome P-450, it has the potential to alter the metabolism of other drugs. The metabolism and excretion of theophylline, warfarin, carbamaz-epine, and methylprednisolone are inhibited by erythromycin [283-286]. As a potent antibiotic, it can also affect metabolism by gut micro-organisms of drugs such as digoxin. At least some of the newer derivatives may cause fewer drug interactions and thus may be better tolerated if co-administered with medications for other illnesses [287-289]. 

Troleandomycin and, to a lesser extent, clarithromycin and erythromycin can reduce the clearance of methylprednisolone, thereby increasing both its therapeutic and adverse effects. A patient receiving long-term clarithromycin developed Cushing s syndrome after starting treatment with inhaled budesonide. There appears to be no pharmacokinetic interaction between erythromycin and inhaled ciclesonide. Similarly, prednisolone appears not to be affected by macrolides, except possibly in those also taking enzyme-inducers such as phenobarbital. Isolated case reports describe the development of acute mania and psychosis in two patients, apparently due to an interaction between prednisone and clarithromycin. 

Erythromydn. A study in 9 asthmatic patients aged 9 to 18 found that after taking erythromycin 250 mg four times daily for a week, the clearance of methylprednisolone was decreased by 46% (range 28 to 61%) and the half-life was increased by 47%, from 2.34 to 3.45 hours. ... 

What is known suggests that clarithromycin, erythromycin and troleandomycin can inhibit the metabolism of methylprednisolone. The volume of distribution is also decreased. Clarithromycin may inhibit the metabolism of budesonide. ... 

Information about the clarithromycin or erythromycin interactions with methylprednisolone is much more limited than with the interaction between troleandomycin and methylprednisolone, but they all appear to be established and of clinical importance. The effect should be taken into account during concurrent use and appropriate dosage reductions made to avoid the development of corticosteroid adverse effects. The authors of one study suggest that this reduction should be empirical, based primarily on clinical symptomatology. Another group found that a 68% reduction in methylprednisolone dosage was possible within 2 weeks. Troleandomycin appears to have a greater effect than erythromycin or clarithromycin. 

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