Phenytoin Chloramphenicol

Chloramphenicol Phenytoin, tolbutamide, ethanol Decreased metabolism of other agents Monitor phenytoin SDC, blood glucose... 

CHLORAMPHENICOL PHENYTOIN t phenytoin levels Inhibited metabolism Monitor phenytoin levels... 

Krasinski K, Kusmiesz H, Nelson JD. Pharmacologic interactions among chloramphenicol, phenytoin and pheno-barbital. Pediatr Infect Dis 1982 l(4) 232-5. 

Powell DA, Nahata MC, Durrell DC, Glazer JP, Hilty MD. Interactions among chloramphenicol, phenytoin, and phenobarbital in a pediatric patient. J Pediatr 1981 98(6) 1001-3. 

Greenlaw CW. Chloramphenicol-phenytoin drug interaction. Drug Intell Clin Pharm (1979) 13,609-10. 

Phenytoin Chloramphenicol, isoniazid, etc. CYP2C9, CYP2C19 Phenytoin intoxication... 

The effects of oral hypoglycemic drugs, oral anticoagulants, and phenytoin may be increased when administered with chloramphenicol. Fhenobarbital or rifampin may decrease chloramphenicol blood levels. 

Phenytoin interacts widi many different drugp. For example isoniazid, chloramphenicol, sulfonamides, benzodiazepines, succinimides, and cimetidine all increase phenytoin blood levels. The barbiturates, rifampin, theophylline, and warfarin decrease phenytoin blood levels. When administering the hydantoins with meperidine, die analgesic effect of meperidine is decreased. 

Acetazolamide, allopurinol, aspirin, captopril, carbamazepine, chloramphenicol, chlorpromazine, dapsone, felbamate, gold salts, metronidazole, methimazole, penicillamine, pentoxifylline, phenothiazines, phenytoin, propylthiouracil, quinidine, sulfonamide antimicrobials, sulfonylureas, and ticlopidine... 

Azathioprine, chloramphenicol, colchicine, cyclophosphamide, cytarabine, 5-fluorodeoxyuridine, 5-fluorouracil, hydroxyurea, mercaptopurine, metformin, methotrexate, phenobarbital, phenytoin, primidone, proton pump inhibitors, pyrimethamine, sulfasalazine, and vinblastine... 

Sulthiame (H7, 04), phcnacoraidc (H15), chloramphenicol (C5),dicou-marol (H6), antituberculous drugs (K23), disulfiram and phenyramidol (S23) have been described as inhibitors of phenytoin metabolism, while alcohol and possibly phenobarbitone have the reverse effect. Clinical and experimental evidence regarding the latter are confusing (B16, B29, C11,C12). 

Drugs that may affect repaglinide include CYP 450 inhibitors (eg, clarithromycin, erythromycin, ketoconazole, miconazole), CYP 450 inducers (eg, barbiturates, carbamazepine, rifampin), beta blockers, calcium channel blockers, chloramphenicol, corticosteroids, coumarins, estrogens, gemfibrozil, isoniazid, itraconazole, levonorgestrel and ethinyl estradiol, MAOIs, nicotinic acid, NSAIDs, oral contraceptives, phenothiazines, phenytoin, probenecid, salicylates, simvastatin, sulfonamides, sympathomimetics, thiazides and other diuretics, and thyroid products. 

Incompatibilities Do not mix IV minocycline before or during administration with any solutions containing the following Adrenocorticotropic hormone (ACTH), aminophylline, amobarbital sodium, amphotericin B, bicarbonate infusion mixtures, calcium gluconate or chloride, carbenicillin, cephalothin sodium, cefazolin sodium, chloramphenicol succinate, colistin sulfate, heparin sodium, hydrocortisone sodium succinate, iodine sodium, methicillin sodium, novobiocin, penicillin, pentobarbital, phenytoin sodium, polymyxin, prochlorperazine, sodium ascorbate, sulfadiazine, sulfisoxazole, thiopental sodium, vitamin K (sodium bisulfate or sodium salt), whole blood. 

Drugs that may interact with zalcitabine include antacids, chloramphenicol, cisplatin, dapsone, didanosine, disulfiram, ethionamide, glutethimide, gold, hydralazine, iodoquinol, isoniazid, metronidazole, nitrofurantoin, phenytoin, ribavirin, vincristine, cimetidine, metoclopramide, amphotericin, aminoglycosides, foscarnet, antiretroviral nucleoside analogs, pentamidine, and probenecid. 

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. 

Phenytoin (Dilantin) [Anticenvulsant/Hydantoin] Uses Sz disorders Action X Sz spread in the motor cortex Dose Load Adults Peds. 15-20 mg/kg IV, 25 mg/min max or PO in 400-mg doses at 4-h intervals Maint Adults. Initial, 200 mg PO or IV bid or 300 mg hs then follow levels Peds. 4-7 mg/kg/24h PO or IV -s- daily-bid avoid PO susp (erratic absorption) Caution [D, +] Contra Heart block, sinus bradycardia Disp Caps, susp, inj SE Nystag-mus/ataxia early signs of tox gum hyperplasia w/ long-term use. IV BP, bradycardia, arrhythmias, phlebitis peripheral neuropathy, rash, blood dyscrasias, Stevens-Johnson synd Notes Levels Trough Just before next dose Therapeutic Peak 10-20 mcg/mL Toxic >20 mcg/mL phenytoin albumin bound, levels = bound free phenytoin w/ i albumin azotemia, low levels may be therapeutic (nl free levels) Interactions T Effects W/ amiodarone, allopurinol, chloramphenicol, disulfiram, INH, omeprazole, sulfonamides, quinolones, trimethoprim t... 

Plasma phenytoin concentrations are increased in the presence of chloramphenicol, disulfiram, and isoniazid, since the latter drugs inhibit the hepatic metabolism of phenytoin. A reduction in phenytoin dose can alleviate the consequences of these drug-drug interactions. 

Only a few well-documented drug combinations with phenytoin may necessitate dosage adjustment. Coadministration of the following drugs can result in elevations of plasma phenytoin levels in most patients cimetidine, chloramphenicol, disulfiram, sulthiame, and isoniazid (in slow acetylators). Phenytoin often causes a decline in plasma carbamazepine levels if these two drugs are given concomitantly. 

Certain concomitantly administered drugs may interfere with the effectiveness of the oral contraceptives or lead to an increased incidence of breakthrough bleeding. These include rifampin, isoniazid, ampiciUin, neomycin, penicillin V, chloramphenicol, sulfonamides, nitrofurantoin, phenytoin, barbiturates, primidone, analgesics, and phenothiazines. 

Chloramphenicol inhibits hepatic microsomal enzymes that metabolize several drugs. Half-lives are prolonged, and the serum concentrations of phenytoin, tolbutamide, chlorpropamide, and warfarin are increased. Like other bacteriostatic inhibitors of microbial protein synthesis, chloramphenicol can antagonize bactericidal drugs such as penicillins or aminoglycosides. 

Drug interactions NSAIDs Salicylates Sulfonamides Chloramphenicol Probenecid Coumarins MAO inhibitors Beta-blockers Thiazides and other diuretics Corticosteroids Phenothiazines Thyroid products Estrogens Oral contraceptives Phenytoin Nicotinic acid Sympathomimetic Calcium channel blockers Isoniazid Miconazole... 

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