Primidone Acetazolamide

Acetazolamide Primidone Interaction probably of little clinical significance Possibly reduced absorption of primidone... 

There is an increased risk of cyclosporine toxicity when the drug is administered with acetazolamide. Decreased serum and urine concentrations of primidone occur when the drug is administered with acetazolamide. 

From the clinical point of view, antiepileptic drugs are primarily divided into two categories those effective in treating major attacks (phenytoin, carbamazepine, mephobarbi-tal, and also primidone), and those effective in treating minor attacks (ethosuximide, acetazolamide, clonazepam, trimethadione, and valproic acid). 

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 may affect primidone include acetazolamide, carbamazepine, hydantoins, isoniazid, nicotinamide, and succinimides. 

For simple and complex partial seizures and secondary generalized tonic-clonic seizures, the first line drugs are - carbamazepine, valproate and phenytoin. Second line drugs include - acetazolamide, clobazam, clonazepam, ethosuximide, felbamate, gabapentin, lamotrigine, levetiracetam, oxacarbamazepine, primidone, tiagabine, topiramate and vigabactin. 

For generalized absence seizures, first line treatment is with valproate or ethosuximide and second line treatment with acetazolamide, clobazam, clonazepam, lamotrigine, phenobarbitone and primidone. 

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. 

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... 

Noninterfering acebutolol, acetazolamide, acetophenetidin, aldosterone, allopurinol, caffeine, cephalothin, chlorothiazide, cotinine, ephedrine, furosemide, hydrochlorothiazide, nicotine, pheniramine, phenylephrine, phenytoin, primidone, quinine, triamcinolone... 

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. 

Severe osteomalacia developed in 2 women taking phenytoin or primidone and phenobarbital when they were given acetazolamide 750 mg daily, despite a normal intake of calcium. When the acetazolamide was withdrawn, the hyperchloraemic acidosis that had been seen in both patients abated and their high urinary excretion of calcium fell by 50%. Similar cases have been described in 3 children given acetazolamide, phenytoin and primidone, with phenobarbital and/or metharbital, who developed rickets. 

A patient taking primidone had an increase in seizure-frequency and a virtual absence of primidone (or phenobarbital) in the serum while taking acetazolamide 250 mg daily. Primidone levels rose when the acetazolamide was withdrawn, probably due to improved absorption. A subsequent study in 2 other patients found that ace olamide had a small effect on primidone absorption in one, and no effect in the other. ... 

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