Prednisone Cimetidine

A 25% incidence of grade 2 or more severe immunological reactions to docetaxel has been reported after the use of oral prednisone (100 mg orally before treatment and 50 mg once on the morning of treatment and the following 2 days) in 20 patients with non-small-cell lung cancers (8). No other premedications were given routinely. If infusion-related symptoms occurred, the infusion was interrupted and diphenhydramine was given. On subsequent cycles those patients then were routinely premedicated with diphenhydramine 25 or 50 mg intravenously and cimetidine 300 mg intravenously. 

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 allopurinol, amiodarone, amobarbital, anabolic steroids, anti-thyroid agents, aprobarbital, aspirin, barbiturates, bivalirudin, butabarbital, butalbital, cimetidine, clofibrate, clopidogrel, cyclosporine, delavirdine, disulfiram, fenofibrate, fluconazole, gemfibrozil, glutethimide, imatinib, itraconazole, ketoconazole, levothyroxine, liothyronine, mephobarbital, methimazole, metronidazole, miconazole, penicillins, pentobarbital, phenobarbital, phenylbutazones, piperacillin, prednisone, primidone, propylthiouracil, quinidine, quinine, rifabutin, rifampin, rifapentine, rofecoxib, salicylates, secobarbital, sulfinpyrazone, sulfonamides, testosterone, thyroid, zileuton... 

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 amprenavir, aprepitant, bedomethasone, buprenorphine, calcium, chloramphenicol, cimetidine, dobazam, clorazepate, cyclosporine, cyproterone, darunavir, dasatinib, delavirdine, dexamethasone, diazoxide, disulfiram, dopamine, fesoterodine, fluconazole, flunisolide, fluoxetine, fosamprenavir, ginkgo biloba, hydrocortisone, imatinib, indinavir, influenza vaccines, isoniazid, isradipine, itraconazole, lacosamide, lapatinib, lopinavir, meperidine, methylprednisolone, midazolam, mivacurium, nelfinavir, nilotinib, nilutamide, phenylbutazone, piracetam, posaconazole, prednisolone, prednisone, primrose, ritonavir, rivaroxaban, sage, saquinavir, solifenacin, St John s wort, sucralfate, telithromycin, temsirolimus, teniposide, ticlopidine, tizanidine, tolvaptan, triamcinolone, uracil/tegafur, vigabatrin... 

The urine of some patients may be reddish brown due to pigments derived from the drug. Oxidative metabolism of metronidazole is induced by phenobarbital, prednisone, rifampin, and possibly ethanol and is inhibited by cimetidine. 

Information seems to be limited but the pharmacokinetic interaction would appear to be established. Just how much it affects the outcome of treatment for systemic worm infections such as cysticercosis is unknown because the optimum praziquantel levels are still uncertain, and it is possible that the metabolites of praziquantel might be active. The authors of one report suggest that dexamethasone should not be given continuously with praziquantel but only used transiently to resolve inflammatory reactions to praziquantel treatment. Alternatively, limited information suggests the addition of cimetidine may allow dexamethasone to be used. Intravenous methylprednisolone has also been used for acute corticosteroid therapy with praziquantel, and oral prednisone has been used longterm to prevent further tissue damage associated with inflammation but the effect of these corticosteroids on the plasma levels of praziquantel do not appear to have been studied. 

Eradiri O, Jamali F, Thomson ABR. Interaction of metronidazole with phenobarbital, cimetidine, prednisone, and sulfasalazine in Crohn s disease. Biopharm Drug Dispos (1988) 9,219-27. 

Limited documentation. Withdrawal of the beta blocker 2 to 3 days before use of contrast media has been suggested, but because of the potential for beta blocker withdrawal syndromes this must be considered on an individual risk/benefit basis. Pretreatment with an antihistamine such as diphenhydramine and a corticosteroid such as prednisone may reduce the risk of reactions. Ephedrine and cimetidine have also been tried, but their use is controversial. Use of low osmolality, non-ionic contrast media may reduce the risk of adverse reactions, including anaphylaxis. However, even mild reactions to contrast media may sensitise the patient and a serious anaphylactoid reaction may occur on further exposure despite pretreatment and the use of low osmolality contrast media. Pre-testing with a small amount of the contrast media has been shown to be a poor predictor of a reaction. ... 

Cimetidine does not interact with prednisolone, prednisone or dexamethasone, and ranitidine does not interact with prednisone. 

Prednisone is a pro-drug, which must be converted to prednisolone within the body to become active. A double-blind crossover study in 9 healthy subjects found that cimetidine 300 mg every 6 hours or ranitidine 150 mg twice daily for 4 days did not significantly alter the pharmacokinetics of prednisolone after a single 40-mg oral dose of prednisone. Another double-blind, crossover study found that cimetidine 1 g daily only caused minor changes in plasma prednisolone levels following a 10-mg dose of enteric-coated prednisolone. Similarly, another study found that cimetidine 600 mg twice daily for 7 days had no effect on the pharmacokinetics of a single 8-mg intravenous dose of dexamethasone sodinm phosphate. ... 

Sirgo MA, Rocci ML, Ferguson RK, Eshelman FN Vlasses PH. Effects of cimetidine and ranitidine on the conversion of prednisone to prednisolone. Clin Pharmacol Ther (1985) 37,534-8. 

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