Methylprednisolone Phenytoin

Aprepitant may be affected by paroxetine, CYP2C9 substrates (eg, phenytoin, tolbutamide, warfarin), CYP3A4 substrates (eg, alprazolam, cisapride, dexamethasone, docetaxel, etoposide, ifosfamide, imatinib, irinotecan, methylprednisolone, midazolam, paclitaxel, pimozide, triazolam, vinblastine, vincristine, vinorelbine), and oral contraceptives. 

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. 

Clinically important, potentially hazardous interactions with alprazolam, astemizole, carbamazepine, cisapride, clarithromycin, dexamethasone, diltiazem, docetaxel, ifosfamide, imatinib, irinotecan, itraconazole, ketoconazole, methylprednisolone, midazolam, nefazodone, oral contraceptives, paroxetine, phenytoin, pimozide, rifampin, ritonavir, terfenadine, tolbutamide, trabectedin, troleandomycin, vinblastine, vincristine, warfarin... 

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... 

Simultaneous acebutolol, acetazolamide, acetophenetidin, adrenosterone, aldosterone, amitriptyline, androsten-3,17-dione, aspirin, carbamazepine, cephalothin, chlorothiazide, dehydrocorticosterone, deoxycorticosterone, deo cortisol, desipramine, dexamethasone, diazepam, equilenin, estradiol, estriol, estrone, fluorometholone, furosemide, hydrochlorothiazide, hydroxycorticosterone, hydroxyprogesterone, hydroxyprogesterone, imip-ramine, indomethacin, methylhydroxyprogesterone, methylprednisolone, nandrolone, nordiazepam, nortriptyline, pheniramine, phenobarbital, phenytoin, prednisolone, prednisone, primidone, probenecid, progesterone, quinine, spironolactone, testosterone, theophylline, triamcinolone, tripelennamine... 

Methylprednisolone Midazolam Nisoldipine Phenytoin Pimozide Quinidine Ritonavir Saquinavir Sildenafil Simvastatin SiroUmus Sulfonylureas (glyburide, others) Tacrolimus Triazolam Trimetrexate Verapamil Ritonavir... 

The interaction between the corticosteroids and phenobarbital is well documented, well established and of clinical importance. Concurrent use need not be avoided but the outcome should be monitored. Increase the corticosteroid dosage as necessary. The extent of the increase is variable. Dex-amethasone, hydrocortisone, " methylprednisolone, prednisone and prednisolone are all known to be affected. Prednisone and prednisolone appear to be less affected than methylprednisolone and may be preferred. Be alert for the same interaction with other corticosteroids and other barbiturates, which also are enzyme-inducers, although direct evidence seems to be lacking. The dexamethasone adrenal suppression test may be expected to be unreliable in those taking phenobarbital, just as it is with pheny-toin, another potent enzyme-inducer. See Corticosteroids + Phenytoin , p.1059. 

The therapeutic effects of dexamethasone, methylprednisolone, prednisolone, prednisone (and probably other glucocorticoids) and fludrocortisone can be markedly reduced by phenytoin. One study su ested that dexamethasone may modestly increase serum phenytoin levels, but another study and two case reports of patients with brain metastases suggest that an important decrease can occur. The results of the dexamethasone adrenal suppression test may prove to be unreliable in those taking phenytoin. 

An infusion of isoprenaline increased the clearance of theophylline (given as intravenous aminophylline) by a mean of 19% in 6 children with status asthmaticus and respiratory failure. Two of them had increases in clearance of greater than 30%. Another study in 12 patients with status asthmaticus found that an isoprenaline infusion (mean maximum rate 0.77 micrograms/kg per minute) caused a mean fall in serum theophylline levels of almost 6 micrograms/mL. The levels rose again when isoprenaline was stopped. A critically ill patient receiving intravenous aminophylline, phenytoin and nebulised terbutaline had a marked 4.5-fold increase in theophylline clearance when an isoprenaline infusion and intravenous methylprednisolone were added to the regimen. ... 

Noninterfering acetaminophen, amitriptyline, aspirin, atenolol, camazepam, carbamaze-pine, chlorimipramine, chlorthalidone, clonazepam, cortisone, desipramine, diazepam, halazepam, hydrochlorothiazide, hydrocortisone, imipramine, lorazepam, maprotiline, meperidine, methylphenobarbital, methylprednisolone, metodopramide, midazolam, morphine, nalorphine, naloxone, nitrazepam, nortriptyline, oxaz am, oxprenolol, phenobar-bital, phenytoin, pindolol, prazepam, prednisolone, prednisone, primidone, prochlorperazine, propranolol, salicylic acid, temazepam... 

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