Phenobarbital Allopurinol

Drugs that may affect cyclosporine include allopurinol, amiodarone, androgens (eg, danazol, methyltestosterone), anticonvulsants (eg, carbamazepine, phenobarbital, phenytoin), azole antifungals (eg, fluconazole, ketoconazole), beta-blockers, bosentan, bromocriptine, calcium channel blockers, colchicine, oral contraceptives, corticosteroids, fluoroquinolones (eg, ciprofloxacin), foscarnet, HMG-CoA reductase inhibitors, imipenem-cilastatin, macrolide antibiotics, methotrexate, metoclopramide, nafcillin, nefazodone, orlistat, potassium-sparing diuretics, probucol, rifamycins (rifampin, rifabutin), serotonin reuptake inhibitors (SSRIs eg, fluoxetine, sertraline),... 

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... 

Drugs that are the most common cause of TEN are allopurinol, ampicillin, amoxicillin, carbamazepine, NSAIDs, phenobarbital, pentamidine, phenytoin (diphenylhydantoin), pyrazolones, and sulfonamides. 

Noninterfering acetaminophen, allopurinol, amikacin, amoxapine, amytal, bretylium, caffeine, carbamazepine, carisoprodol, chloramphenicol, chlordiazepoxide, chlorpropamide, clonazepam, codeine, diazepeun, disop30 amide, droperidol, ethinamate, ethinamate, etho-suximide, fluphenazine, flurazepam, furosemide, gentamicin, haloperidol, hydrochlorothiazide, hydro yzine, ibuprofen, kanamycin, lidocaine, loxapine, meperidine, mepho-barbital, meprobamate, methaqualone, methotrexate, morphine, nafcUlin, naloxone, neomycin, perphenazine, phenacetin, phenobarbital, phenytoin, prazepam, primidone, procaine, propoxyphene, reserpine, salicylamide, salicylic acid, secobarbital, spironolactone, theophyUine, thiopental, thioridazine, tobramycin, valproic acid, verapeunil... 

Simultaneous acetaminophen, aldosterone, allopurinol, amitriplyline, caffeine, calcitriol, cephalothin, chlordiazepoxide, chlorothiazide, corticosterone, cortisone, dexamethasone, diazepam, ephedrine, ethinyl estradiol, furosemide, hydrocortisone, ibuprofen, imipra-mine, indomethacin, mechlorethamine, methylprednisone, metolazone, nandrolone, naproxen, phenacetin, phenobarbital, phen3doin, probenecid, progesterone, propranolol, sulfasalazine, testosterone, theophylline, vincristine... 

Allopurinol appears not to alter phenobarbital levels, including those derived from primidone. 

In a study of add-on therapy, allopurinol (150 mg daily in those less than 20 kg, and 300 mg daily for other patients) for 4 months, had no effeet on phenobarbital levels in 46 patients taking antiepileptics including phenobarbital. In another similar study, allopurinol 10 mg/kg increased to 15 mg/kg daily for 12 weeks had no effect on serum phenobarbital levels in 11 patients taking primidone or phenobarbital with or without other an-tiepileptics. Therefore phenobarbital or primidone dosage alterations are unlikely to be required if allopurinol is used. 

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