Phenobarbital Acetazolamide

Acetazolamide Phenobarbital Interaction probably of little clinical significance Unknown... 

From the chemical point of view, formally, antiepileptic drugs could be classified as derivatives of hydantoins (phenytoin, mephenytoin, ethotoin), barbiturates (phenobarbital, mephobarbital, and primidone), succinimides (ethosuximide, methosuximide, phensux-imide), benzodiazepines (diazepam, chlorodiazepoxide, clonazepam, lorazepam), oxazo-lidines (trimethadione, paramethadione), and also valproic acid, carbamazepine, and acetazolamide. 

Drugs that bind strongly to red blood cells may exhibit concentration-dependent uptake from plasma. This is reported for acetazolamide, chlorthali-done, and cyclosporine. " The determination of the blood to plasma (B/P) ratios can be method specific. For example, the determination of the B/P ratio of cyclosporine A increases from 1.5-3.0 when estimated at body temperature (37°C) compared with a ratio of 2.5-10.0 at room temperature (20°C). Drugs reported to bind strongly to the erythrocytes (B/P ratio > 1) are promazine, chlorpromazine, propranolol, salicylate, phenobarbital, pentazocine, and phenytoin. " ... 

Incompatible with phenobarbital sodium, diazepam solution at a pH 5, ° some binary powder mixtures, lansoprazole, and formaldehyde. Acids will dissolve magnesium carbonate, with the liberation of carbon dioxide. Slight alkalinity is imparted to water. Magnesium carbonate was also found to increase the dissolution of acetazolamide formulations at a pH of 1.12 however, dissolution was retarded at a pH of 7.4. ... 

Co-administration of acetazolamide with primidone results in decreased gastrointestinal absorption of primidone and subsequent diminished plasma concentrations. Primidone administered in association with phenytoin produces a modest elevation of the phenobarbital/primidone ratio because phenytoin competes with the hepatic hydroxylating enzymes associated with phenobarbitaFs metabolism. Coadministration of valproic acid, for the same reasons out-fined for phenobarbital, causes a modest increase in both primidone and phenobarbital serum concentrations. 

Importantly, Loscher et al. found that carbamazepine, felbamate, gabapentin, lamotrigine, phenobarbital, and topiramate are substrates of ABCBl (P-gp) [38]. Crowe et al. also studied the transport of a variety of antiepileptic drugs including vigabatrin, gabapentin, phenobarbitone, lamotrigine, phenytoin, carbamazepine, and acetazolamide in colorectal tumor-derived Caco-2 cell monolayers. They found that only one antiepileptic, acetazolamide, is a weak ABCBl substrate [39]. 

Also analyzed acebutolol, acepromazine, acetaminophen, acetazolamide, acetophenazine, albuterol, amitriptyline, amobarbital, amoxapine, antipsrrine, atenolol, atropine, azata-dine, baclofen, benzocaine, bromocriptine, brompheniramine, brotizolam, bupivacaine, buspirone, butabarbital, butalbital, caffeine, carbamazepine, cetirizine, chlorqyclizine, chlordiazepoxide, chlormezanone, chloroquine, chlorpheniramine, chlorpromazine, chlorpropamide, chlorprothixene, chlorthalidone, chlorzoxazone, cimetidine, cisapride, clomipramine, clonazepam, clonidine, clozapine, cocaine, codeine, colchicine, qyclizine, (yclo-benzaprine, dantrolene, desipramine, diazepam, diclofenac, diflunisal, diltiazem, diphenhydramine, diphenidol, dipheno late, dipyridamole, disopyramide, dobutamine, doxapram, doxepin, droperidol, encainide, ethidium bromide, ethopropazine, fenoprofen, fentanyl, flavoxate, fluoxetine, fluphenazine, flurazepam, flurbiprofen, fluvoxamine, fii-rosemide, glutethimide, glyburide, guaifenesin, haloperidol, homatropine, hydralazine, hydrochlorothiazide, hydrocodone, hydromorphone, hydro g chloroquine, hydroxyzine, ibuprofen, imipramine, indomethacin, ketoconazole, ketoprofen, ketorolac, labetalol, le-vorphanol, lidocaine, loratadine, lorazepam, lovastatin, loxapine, mazindol, mefenamic acid, meperidine, mephenytoin, mepivacaine, mesoridazine, metaproterenol, methadone, methdilazine, methocarbamol, methotrexate, methotrimeprazine, methoxamine, methyl-dopa, methylphenidate, metoclopramide, metolazone, metoprolol, metronidazole, midazolam, moclobemide, morphine, nadolol, nalbuphine, naloxone, naphazoline, naproxen, nifedipine, nizatidine, norepinephrine, nortriptyline, oxazepam, oxycodone, oxymetazo-line, paroxetine, pemoline, pentazocine, pentobarbital, pentoxifylline, perphenazine, pheniramine, phenobarbital, phenol, phenolphthalein, phentolamine, phenylbutazone, phenyltoloxamine, phenytoin, pimozide, pindolol, piroxicam, pramoxine, prazepam, prazosin, probenecid, procainamide, procaine, prochlorperazine, procyclidine, promazine, promethazine, propafenone, propantheline, propiomazine, propofol, propranolol, protriptyline, quazepam, quinidine, quinine, racemethorphan, ranitidine, remoxipride, risperidone, salicylic acid, scopolamine, secobarbital, sertraline, sotalol, spironolactone, sulfinpyrazone, sulindac, temazepam, terbutaline, terfenadine, tetracaine, theophylline, thiethyl-perazine, thiopental, thioridazine, thiothixene, timolol, tocainide, tolbutamide, tolmetin, trazodone, triamterene, triazolam, trifluoperazine, triflupromazine, trimeprazine, trimethoprim, trimipramine, verapamil, warfarin, xylometazoline, yohimbine, zopiclone... 

Extracted acetazolamide, ampicillin, bromazepam, caffeine, chloramphenicol, chlorothiazide, diazepam, droperidol, ethionamide, furosemide, isoniazid, methadone, penicillin G, phenobarbital, phenytoin, prazepam, propoxyphene, pyrazinamide, rifampin, trimepra-zine, trimethoprim... 

Simultaneous acebutolol, acetazolamide, acetophenetidin, adrenosterone, aldosterone, amitriptyline, androsten-3,17-dione, aspirin, carbamazepine, cephalothin, chlorothiazide, dehydrocorticosterone, deoxycorticosterone, deo cortisol, desipramine, dexamethasone, diazepam, equilenin, estradiol, estriol, estrone, fluorometholone, furosemide, hydrochlorothiazide, hydroxycorticosterone, hydroxyprogesterone, hydroxyprogesterone, imip-ramine, indomethacin, methylhydroxyprogesterone, methylprednisolone, nandrolone, nordiazepam, nortriptyline, pheniramine, phenobarbital, phenytoin, prednisolone, prednisone, primidone, probenecid, progesterone, quinine, spironolactone, testosterone, theophylline, triamcinolone, tripelennamine... 

Extracted carbamazepine, ethosuximide, phenobarbital, primidone Simultaneous amobarbital, barbital, chlordiazepoxide, codeine, ethotoin, glutethimide, hexobarbital, hydrocortisone, mephenytoin, mephobarbital, metharbital, methsuximide, nitrazepam, phenacetin, phensixximide, secobarbital Noninterfering acetaminophen, acetazolamide, amphetamine, bilirubin, caffeine, diazepam, dimenhydrinate, meperidine, meprobamate, methamphetamine, methaqualone, methylphenidate, nicotine, propoxyphene, theophylline, valproic acid Interfering pentobarbital... 

Noninterfering acetaminophen, acetazolamide, albuterol, amitriptyline, amobarbital, car-bamazepine, diazoxide, disopyramide, ethosuximide, isoproterenol, nitrazepam, nortriptyline, oxazepam, pentobarbital, phenobarbital, phenytoin, primidone, procainamide, salicylic acid, sulthiame... 

Primidone use Is associated with decreases In CBZ, lamotrigine, valproate, tiagabine, and zonisamide serum levels. Primidone levels are increased by nicotinamide and Isonlazid. Hydantoins increase the plasma concentrations of primidone, phenobarbital, and PEMA. CBZ Increases levels of phenobarbital derived from primidone. Primidone levels are decreased by succinimides, CBZ, and acetazolamide. 

Severe osteomalacia and rickets have been seen in a few patients taking phenytoin, phenobarbital, or primidone with acetazola-mide. A marked reduction in serum primidone levels with a loss in seizure controi, rises in serum carbamazepine levels with toxicity, and rises in phenytoin levels have also been described in a veiy small number of patients given acetazolamide. 

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