Ketoconazole with rifampin

Engelhard D, Stutman HR,hIarks MI. Interaction of ketoconazole with rifampin and isoniazid. NEnglJ Med ( 9S4) 3], 1681-3. 

Ketoconazole (a potent inhibitor of CYP3A4) has been shown to increase the oral bioavailability of cyclosporin from 22 to 56% [50]. This consisted of a 1.8-fold decrease in systemic clearance combined with a 4.9-fold decrease in oral clearance. The authors estimated that hepatic extraction was decreased only 1.15-fold, whereas the oral bioavailability increased 2.6-fold and the observation was attributed to decreased intestinal metabolism. Erythromycin was also shown to increase the oral bioavailability of cyclosporin A 1.7-fold, while pre-treatment with rifampin (an inducer of CYP3A4) decreased oral bioavailability of cyclosporin from 27% to 10% due to a 4.2-fold increase in oral clearance but only a 1.2-fold increase in systemic clearance. Floren et al. [51] have also shown that ketoconazole can double the oral bioavailability of tacrolimus in man by inhibiting gut wall CYP3A4. 

Clinically important, potentially hazardous interactions with alcohol, clotrimazole, itraconazole, ketoconazole, phenytoin, rifampin, ritonavir, St John s wort... 

Drugs that may interact with isoniazid include acetaminophen, carbamazepine, chlorzoxazone, disulfiram, enflurane, hydantoins, ketoconazole, rifampin, and theophylline. 

Nevirapine induces and is metabolized by CYP3A4 therefore, coadministration of drugs that induce or are metabolized by this isoenzyme may result in interactions. Nevirapine may decrease the effectiveness of ethinyl estradiol-based contraceptives and can lower plasma concentrations of methadone. Nevirapine should not be administered with ketoconazole, rifampin, or rifabutin. 

Although specific drug or food interactions with mifepristone have not been studied, on the basis of this drug s metabolism by CYP3A4, it is possible that ketoconazole, itraconazole, erythromycin, and grapefruit juice may inhibit its metabolism (increasing serum levels of mifepristone). Furthermore, rifampin, dexamethasone, St. John s wort, and certain anticonvulsants (e.g., phenytoin, phenobarbital, and carbamazepine) may induce mifepristone metabolism (lowering serum levels of mifepristone)... 

Delavirdine is extensively metabolized to inactive metabolites by the CYP3A and CYP2D6 enzymes. However, it also inhibits CYP3 A and thus inhibits its own metabolism. In addition to its interactions with other antiretroviral agents (see Table 49 1), delavirdine will result in increased levels of numerous agents (Table 49-3). Dose reduction of indinavir and saquinavir should be considered if they are administered concurrently with delavirdine. Delavirdine plasma concentrations are reduced in the presence of antacids, phenytoin, phenobarbital, carbamazepine, rifabutin, and rifampin concentrations are increased during coadministration with clarithromycin, fluoxetine, dexamethasone, and ketoconazole. 

Since indinavir is a substrate as well as an inhibitor of CYP3 A4, numerous and complex drug interactions can occur as described above. Indinavir levels decrease with concurrent use of rifabutin, fluconazole, St. John s wort, and rifampin. Caution is advised with other 3 A4 inducers also, including phenobarbital, phenytoin, carbamezepine, and dexamethasone. Dose reduction of indinavir should be considered if coadministered with delavirdine, ketoconazole, or itraconazole, while an increase in the dose of indinavir is indicated if the drug is coadministered with efavirenz or rifabutin. 

Inhibitors of OATP transport are typically ster-ically bulky compounds, including anions, cations, and neutral compounds (95). Various medications have been shown to interact with OATPs, including HMG CoA reductase inhibitors, cyclosporine, quinidine, rifampin, ketoconazole, verapamil, and certain protease inhibitors. Cyclosporine and rifampin have relatively high ratios of plasma concentration to Ki, suggesting the potential for clinically significant drug-drug interactions via modulation of OATP. On the other hand, plasma concentrations of pravastatin are... 

Clinically important, potentially hazardous interactions with amiodarone, anabolic steroids, antithyroid agents, barbiturates, bivalirudin, cimetidine, clofibrate, clopidogrel, cyclosporine, delavirdine, dextrothyroxine, disulfiram, fluconazole, glutethimide, imatinib, itraconazole, ketoconazole, metronidazole, miconazole, penicillins, phenylbutazones, piperacillin, quinidine, quinine, rifabutin, rifampin, rifapentine, rofecoxib, salicylates, sulfinpyrazone, sulfonamides, testosterone, thyroid, zileuton... 

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... 

Clinically important, potentially hazardous interactions with amiodarone, atorvastatin, bepridil, carbamazepine, delavirdine, dihydroergotamine, etravirine, flecainide, itraconazole, ketoconazole, lidocaine, lopinavir, lovastatin, midazolam, phenobarbital, phenytoin, pimozide, propafenone, quinidine, rifabutin, rifampin, sildenafil, simvastatin, St John s wort, triazolam, vardenafil, warfarin... 

Clinically important, potentially hazardous interactions with amprenavir, aprepitant, atazanavir, carbamazepine, chlorpheniramine, cimetidine, clarithromycin, clorazepate, CNS depressants, darunavir, delavirdine, dexamethasone, efavirenz, erythromycin, esomeprazole, fluconazole, fluoxetine, fosamprenavir, grapefruit juice, griseofulvin, imatinib, indinavir, itraconazole, ivermectin, ketoconazole, lopinavir, nelfinavir, nevirapine, phenobarbital, phenytoin, primidone, rifabutin, rifampin, ritonavir, roxithromycin, saquinavir, St John s wort, telithromycin, tipranavir... 

Clinically important, potentially hazardous interactions with aluminum, aminophylline, aspirin, chlorambucil, cimetidine, clarithromycin, cyclophosphamide, cyclosporine, dicumarol, diuretics, docetaxel, estrogens, grapefruit juice, indomethacin, influenza vaccines, itraconazole, ketoconazole, lansoprazole, live vaccines, methotrexate, montelukast, omeprazole, oral contraceptives, pancuronium, phenobarbital, phenytoin, ranitidine, rifampicin, rifampin, timolol, tolbutamide, vitamin A... 

Clinically important, potentially hazardous interactions with alfentanil, alfuzosin, alprazolam, amiodarone, amprenavir, aprepitant, astemizole, atazanavir, bepridil, buprenorphine, bupropion, carbamazepine, chlordiazepoxide, ciclesonide, clozapine, conivaptan, cyclosporine, cyproterone, dasatinib, diazepam, dihydroergotamine, ergot alkaloids, estazolam, eszopidone, etravirine, ezetimibe, fentanyl, fesoterodine, flecainide, flurazepam, fluticasone, halazepam, ivabradine, ixabepilone, ketoconazole, lapatinib, levothyroxine, meperidine, meptazinol, methysergide, midazolam, nifedipine, nilotinib, oral contraceptives, phenytoin, pimozide, piroxicam, propafenone, propoxyphene, quazepam, quinidine, ranolazine, rifabutin, rifampin, rifapentine, rimonabant, rivaroxaban, saquinavir, sildenafil, silodosin, simvastatin, solifenacin, St John s wort, tadalafil, temsirolimus, trabectedin, triazolam, vardenafil, voriconazole, zolpidem... 

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