Isoniazid Theophylline

Low antiepileptic drug levels, drug overdose (e.g., cocaine, isoniazid, theophylline, phenothiazine), ethanol-related, and drug withdrawal... 

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. 

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 benzodiazepines include alcohol, antacids, barbiturates, cimetidine, disulfiram, fluoxetine, isoniazid, ketoconazole, metoprolol, oral contraceptives, narcotics, probenecid, propoxyphene, propranolol, ranitidine, rifampin, scopolamine, theophylline, and valproic acid. 

Drugs that may affect benzodiazepines include alcohol/CNS depressants, cimetidine, oral contraceptives, disulfiram, isoniazid, probenecid, rifampin, smoking, theophyllines, and macrolides. 

Drugs that may interact with disulfiram include alcohol, benzodiazepines, caffeine, chlorzoxazone, cocaine, hydantoins, isoniazid, metronidazole, theophylline, tricyclic antidepressants, and warfarin. 

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

Estazolam potentiates the CNS depressant effects of phenothiazines, narcotics, antihistamines, MAOIs, barbiturates, alcohol, general anesthetics, and TCAs. Use with cimetidine, disulfiram, oral contraceptives, and isoniazid may diminish hepatic metabolism and result in increased plasma concentrations of estazolam and increased CNS depressant effects. Fleavy smoking (more than 20 cigarettes/day) accelerates estazolam s clearance. Theophylline antagonizes estazolam s pharmacological effects. 

Seizures, muscular hyperactivity, and rigidity may result in death. Seizures may cause pulmonary aspiration, hypoxia, and brain damage. Hyperthermia may result from sustained muscular hyperactivity and can lead to muscle breakdown and myoglobinuria, renal failure, lactic acidosis, and hyperkalemia. Drugs and poisons that often cause seizures include antidepressants, theophylline, isoniazid (INH), diphenhydramine, antipsychotics, cocaine, and amphetamines. 

Isoniazid Isoniazid is incompatible with sugars. Isoniazid overdose may be severe to fatal, and treatment is symptomatic and supportive, including stomach wash for control of convulsions and treating metabolic acidosis. Administration of pyridoxine and hemodialysis may be needed. Isoniazid interacts with carba-mazepine, phenytoin, diazepam, triazolam, chlorzoxazone, theophylline, ethosux-imide, enflurane, cycloserine, and warfarin. 

AZITHROMYCIN, CLARITHROMYCIN, ERYTHROMYCIN THEOPHYLUNE 1. t theophylline levels 2. Possibly i eiythromycin levels when given orally 1. Inhibition of CYP2D6-mediated metabolism of theophylline (macrolides and quinolones -isoniazid not known) 2.1 bioavailability uncertain mechanism 1. Monitor theophylline levels before, during and after co-administration 2. Consider an alternative macrolide... 

ISONIAZID BRONCHODILATORS -THEOPHYLLINE t theophylline levels Uncertain Monitor theophylline levels before, during and after co-administration... 

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... 

Increased effects (P450 3A4 inhibitors) cimetidine, danazol, diltiazem, erythromycin, troleandomycin, clarithromycin, fluoxetine, isoniazid, niacinamide, nicotinamide, propoxyphene, ketoconazole, itraconazole, verapamil,and valproate Decreased effects (P450 3A4 inducers) cisplatin, doxorubicin, felbamate, rifampin, phenobarbital, phenytoin, primidone, theophylline... 

Antidepressants selective serotonin reuptake inhibitors, tricyclic antidepressants Antihypertensives felodipine Antibiotics quinolones, isoniazid Bronchodilators albuterol, theophylline Corticosteroids prednisone Dopa agonists levodopa Herbals ma huang, ginseng, ephedra Nonsteroidal anti-inflammatory drugs ibuprofen Stimulants amphetamines, methylphenidate, caffeine, cocaine Sympathomimetics pseudoephedrine Thyroid hormones levothyroxine Toxicity anticholinergics, antihistamines, digoxin Withdrawal alcohol, sedatives... 

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