Nisoldipine Phenytoin

Drugs that may affect fluconazole include cimetidine, hydrochlorothiazide, and rifampin. Drugs that may be affected by fluconazole include alfentanil, benzodiazepines, buspirone, carbamazepine, cisapride, oral contraceptives, corticosteroids, cyclosporine, haloperidol, HMG-CoA reductase inhibitors, losartan, nisoldipine, phenytoin, protease inhibitors, rifabutin, sirolimus, sulfonylureas, tacrolimus, theophylline, tolterodine, tricyclic antidepressants, vinca alkaloids, warfarin, zidovudine, and zolpidem. 

Itraconazole Alfentanil, alprazolam, astemizole, atorvastatin, buspirone, cisapride, cyclosporine, delavirdine, diazepam, digoxin, felodipine, indinavir, loratadine, lovastatin, midazolam, nisoldipine, phenytoin, quinidine, ritonavir, saquinavir, sildenafil, simvastatin, sirolimus, tacrolimus, triazolam, verapamil, warfarin... 

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

CALCIUM CHANNEL BLOCKERS PHENYTOIN 1. Phenytoin levels are t by diltiazem and possibly nifedipine and isradipine 2.1 plasma concentrations of diltiazem, felodipine, nisoldipine, verapamil and possibly nimodipine 1. Postulated to be due to inhibition of CYP3A4-mediated metabolism of phenytoin. Diltiazem is also known to inhibit intestinal P-gp, which may t the bioavailability of phenytoin 2. Phenytoin induces CYP3A4, which metabolizes calcium channel blockers 1. Monitor phenytoin levels when initiating calcium channel blockers, particularly diltiazem and verapamil 2. Monitor PR and BP closely watch for t BP when starting phenytoin in patients already on calcium channel blockers... 

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... 

The plasma levels of felodipine and nisoldipine are very markedly reduced by phenytoin (either alone or with carbamazepine). Case reports surest that nimodipine and verapamil levels may be reduced by phenytoin, and that phenytoin levels may be raised by nifedipine. 

Twelve epileptic patients reeeiving long-term phenytoin treatment and 12 healthy subjeets were given single 40- or 20-mg doses of nisoldipine. The mean nisoldipine AUCs (normalised for a 20-mg dose) were... 

Information about the effects of calcium-channel blockers on phenytoin is limited, but what is known indicates that if diltiazem is given with phenytoin, the dosage of phenytoin may possibly need to be reduced to avoid toxicity. The case report of phenytoin toxicity with nifedipine is isolated, and of unknown importance. Phenytoin markedly reduces felodipine, verapamil and possibly nifedipine levels. Although not all calcium-channel blockers have been studied, most would be expected to interact with phenytoin similarly, as they are metabolised by the same isoenzymes (see Calcium-channel blockers , (p.860)). A considerable increase in the dosage of any calcium-channel blocker will probably be needed in the presence of phenytoin. Note that the manufacturers of nimodipine and nisoldipine contraindieate the eoneurrent use of phenytoin because of the possibility of a large reduction in their levels. 

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