Topiramate Primidone

Commonly used drugs that induce liver enzymes (rifampin, phenytoin, carbamazepine, barbiturates, primidone, topiramate) and reduce efficacy of CHC... 

Clinically important, potentially hazardous interactions with carbamazepine, lamotrigine, phenobarbital, primidone, topiramate, valproic acid, vigabatrin... 

Anticonvulsants (barbiturates, including phenobar-bital and primidone carbamazepine felbamate phenytoin topiramate vigabatrin)... 

Drugs that can decrease carbamazepine serum levels include charcoal, cisplatin, doxorubicin, felbamate, hydantoins, rifampin, phenobarbital, primidone, theophylline. The serum levels of oral contraceptives, haloperidol, bupropion, anticoagulants, felbamate, valproic acid, felodipine, tricyclic antidepressants, acetaminophen, ziprasidone, voriconazole, topiramate, tiagabine, olanzapine, and lamotrigine can be lowered by carbamazepine. 

Partial seizures Carbamazepine Phenytoin Lamotrigine Valproic acid Oxcarbazepine Gabapentin Topiramate Levetiracetam Zonisamide Tiagabine Primidone, phenobarbital Felbamate... 

Tonic-clonic Phenytoin, carbamazepine, valproic acid Lamotrigine, topiramate, phenobarbital, primidone, oxcarbazepine... 

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 atypical absence, tonic and clonic seizures, first line treatment is with valproate and second line with acetazolamide, carbamazepine, clobazam, clonazepam, ethosuximide, felbamate, lamotrigine, oxacarbamazepine, phenobarbitone, phenytoin, primidone or topiramate. 

Drug interactions involving AEDs are shown in Table 52-5. Phenobarbital, phoiytom, primidone and carbamazepine are potent inducers of cytochrome P450 (CYP450), epoxide hydrolase, and uridine diphosphate gjucuronosyltransferase enzyme systems. Valproic acid inhibits many hepatic enzjrme systems and displaces some drugs from plasma albumin. Felbamate and topiramate can act as inducers with some isoforms and inhibitors with others. 

Phenobarbital Phenytoin Primidone Felbamate Lamotrigine Tiagabide Topiramate Valproate Zonisamide Clobazam Clonazepam Diazepam usually compensated by the effect of the added drug risk of toxicity when interfering drug is discontinued drug... 

Carbamazepine, phenytoin, phenobarbital and primidone, felbamate, oxcarbazepine, and topiramate stimulate the metabolism of oral contraceptive steroids. 

Past history of breast cancer, but no evidence of recurrence for 5 years Use of drugs that affect liver enzymes (rifampicin, rifabutin and griseofulvin) anticonvulsants (phenytoin, carbamazepine, barbiturates, topiramate, and primidone)... 

Tonic-clonic seizure As described above for partial with secondarily generalized tonic-clonic seizures except that it is not preceded by a partial seizure. Carbamazepine, phenobarbital, phenytoin, primidone, valproate Lamotrigine, topiramate... 

Topiramate appears not to alter the pharmacokinetics of phenobarbital or primidone. Phenobarbital reduces topiramate levels. 

A review of data from double blind, plaeebo-eontrolled studies found that over periods of 8 to 12 weeks the plasma levels of phenoharhital or primidone in patients (number not stated) with partial seizures remained unchanged when they were also given topiramate. ... 

When topiramate is added to existing treatment with phenytoin or phenobarbital its dose should be titrated to effect. If phenobarbital or primidone are withdrawn or added, be aware that the dose of topiramate may need adjustment. 

Antiepileptics Barbiturates (e.g. phenobarbital, primidone), Carbamazepine, Phenytoin, Topiramate... 

Endocrine A 43-year-old patient with type 1 diabetes attained very good blood sugar control with minimal insulin requirement over a period of 5 years while taking topiramate 8-13 mg/kg/day in addition to other AEDs (initially VPA, then lamotrigine and subsequently primidone) [169 ]. Topiramate, which has previously been noted to have antidiabetic properties in patients with type 2 diabetes, was thought to play a role in protecting p-cell function in this patient. 

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