Isoniazid Carbamazepine

Isoniazid Carbamazepine, phenytoin Decreased metabolism of other agents (nausea, vomiting, nystagmus, ataxia) Monitor drug SDC... 

ISONIAZID CARBAMAZEPINE t carbamazepine levels Inhibited metabolism Monitor carbamazepine levels... 

Allopurinol, barbiturates, benzodiazepines, captopril, carbamazepine, erythromycin, fluoroquinolones, isoniazid, NSAIDs, penicillins, phenothiazines, phenytoin, rifampin, sulfonamides antimicrobials, and tetracyclines... 

Atenolol, hydralazine, procainamide, quinidine, carbamazepine, chlorpromazine, ethosuximide, isoniazid, methyldopa, minocycline, penicillamine, phenylbutazone, phenytoin, thiazides, and valproic acid... 

Certain medications (e.g., cimetidine, diltiazem, erythromycin, fluoxetine, fluvoxamine, isoniazid, itraconazole, ketoconazole, nefazodone, propoxyphene, and verapamil) added to carbamazepine therapy may cause carbamazepine toxicity. 

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. 

Agents that may decrease theophylline levels include aminoglutethimide, barbiturates, charcoal, hydantoins, ketoconazole, rifampin, smoking (cigarettes and marijuana), sulfinpyrazone, sympathomimetics ( -agonists), thioamines, carbamazepine, isoniazid, and loop diuretics. 

Agents that may increase theophylline levels include allopurinol, beta blockers (nonselective), calcium channel blockers, cimetidine, oral contraceptives, corticosteroids, disulfiram, ephedrine, influenza virus vaccine, interferon, macrolides, mexiletine, quinolones, thiabendazole, thyroid hormones, carbamazepine, isoniazid, and loop diuretics. 

Drugs that may affect APAP include barbiturates, carbamazepine, hydantoins, isoniazid, rifampin, sulfinpyrazone, ethyl alcohol, and activated charcoal. 

Drugs that can increase carbamazepine serum levels include cimetidine, danazol, diltiazem, erythromycin, felbamate, clarithromycin, fluoxetine, isoniazid, niacinamide, propoxyphene, ketaconazole, itraconazole, verapamil, valproate, troleandomycin, loratadine, nicotinamide, tricyclic antidepressants, SSRIs, nefazodone, protease inhibitors. 

Drugs that may affect ketoconazole include antacids, didanosine, histamine H2 antagonists, isoniazid, sucralfate, proton pump inhibitors, and rifampin. Drugs that may be affected by ketoconazole include oral anticoagulants, corticosteroids, cyclosporine, protease inhibitors, tricyclic antidepressants, carbamazepine. 

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

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. 

Cimetidine, propoxyphene, and isoniazid also have been reported to inhibit metabolism of carbamazepine. It is essential to monitor blood levels and adjust the dose if necessary whenever additional drugs are given to patients taking carbamazepine. 

Carbamazepine Cimetidine, dextropropoxyphene, erythromycin, isoniazid Potentiation. 

Wright JM, Stokes EF, Sweeney VP. Isoniazid-induced carbamazepine toxicity and vice versa a double drug interaction. N EnglJ Med 1982 307 1325-1327. 

Ethosuximide Ethosuximide interacts with isoniazid, phenytoin, phenobarbi-tone, carbamazepine, valproic acid, antipsychotics, and antidepressants.193... 

Isoniazid can cause convulsions and therefore should be prescribed with caution in patients with epilepsy. Isoniazid is an enzyme inhibitor and may increase carbamazepine levels. Rifampicin is an enzyme inducer and may decrease carbamazepine levels. 

Rifampicin is an enzyme inducer and can increase the incidence and severity of isoniazid-induced hepatitis. Carbamazepine is an enzyme induction agent and interacts with isoniazid, increasing its hepatotoxicity. Isoniazid toxicity is associated with fast acetylator genotype. Although his phenotype was unknown, the interaction with carbamazepine increases risk of this toxicity. 

Tranquillisers hQn Qx do, captodiame, clopenthixol, flupen-thixol, haloperidol, phenothiazines, prothipendyl, trifluperidol Vitamins acetomenaphthone, ascorbic acid, ergocalciferol, nicotinamide, pyridoxine, riboflavine, thiamine Xanthines acepifylline, bamifylline, bufylline, caffeine, dipro-phylline, etamiphylline, theobromine, theophylline Miscellaneous substances aminosalicylic acid, benzoic acid, betanaphthol, carbamazepine, chlorphenesin, dibromoprop-amidine, diethylpropion, halquinol, isoniazid, methaqualone, metronidazole... 

Isoniazid inhibits the metabolism of phenytoin, carbamazepine and ethosuximide, increasing their effect. 

Exfoliative dermatitis and erythroderma gold, phenytoin, carbamazepine, allopurinol, penicillins, neuroleptics, isoniazid. 

Acute hepatocellular necrosis. This reaction varies from a transient disturbance of liver function tests to acute hepatitis. It can be induced by several drugs including general anaesthetics (halothane), antiepileptics (carbamazepine, phenytoin, sodium valproate, phenobarbital), antidepressants (MAO inhibitors), antiinflammatory drugs (indomethacin, ibuprofen), antimicrobials (isoniazid, sulphonamides, nitrofurantoin) and cardiovascular drugs (methyldopa, hydralazine). 

Similarly, drugs given for the treatment of associated disorders may inhibit the metabolism of anticonvulsants and precipitate signs of intoxication (Table 3). Examples include the increase in serum phenytoin concentrations by isoniazid and the increase in serum carbamazepine concentrations by verapamil, diltiazem, and most macrolide antibiotics (175-179). 

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