Primidone Lamotrigine

Valproic acid Carbamazepine, Phenytoin Lamotrigine, Primidone, Phenobarbital... 

When carbamazepine is administered with primidone, decreased primidone levels and higher carbamazepine serum levels may result. Cimetidine administered with carbamazepine may result in an increase in plasma levels of carbamazepine that can lead to toxicity. Blood levels of lamotrigine increase when the agent is administered with valproic acid, requiring a lower dosage of lamotrigine... 

The apparent clearance of lamotrigine is affected by the coadministration of AEDs. Lamotrigine is eliminated more rapidly in patients who have been taking hepatic enzyme inducing antiepileptic drugs (ElAEDs), including carbamazepine, phenytoin, phenobarbital, and primidone. 

Lamotrigine Added to Carbamazepine, Phenytoin, Phenobarbital, or Primidone (Without Valproic Acid) in Patients >12 Years of Age ... 

Discontinuing carbamazepine, phenytoin, phenobarbital, or primidone should prolong the half-life of lamotrigine discontinuing valproate should shorten the half-life of lamotrigine. 

Stopping oral contraceptives - For women not taking carbamazepine, phenytoin, phenobarbital, primidone, or rifampin, the maintenance dose of lamotrigine may need to be decreased by as much as 50% of the maintenance dose with concurrent oral contraceptives. 

Drugs that may affect lamotrigine include acetaminophen, carbamazepine, folate inhibitors, oral contraceptives, phenobarbital, phenytoin, primidone, rifamycins, succinimides, and valproic acid. 

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. 

Lamotrigine is metabolized by glucuronidation, possibly by the UGT 1A4 system. As such, it is vulnerable to other UGT inducers—oral contraceptives, phenytoin, carbamazepine, phenobarbital and primidone, and to a UGT inhibitor, valproate (Hachad et ah, 2002). 

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

Myoclonic seizures are best treated with valproate but, as a second choice, with clobazam, clonazepam, ethosuximide, lamotrigine, phenobarbitone, piracetam or primidone. 

VALPROATE 1. BARBITURATES -phenobarbital, primidone 2. 7ETHOSUXIMIDE 3. LAMOTRIGINE t levels of these antiepileptics Uncertain Watch for early features of toxicity. Measure levels where possible... 

Also, if concomitant enzyme-inducing antiepileptic drugs such as carbamazepine, phenobarbital, phenytoin, and primidone are discontinued after lamotrigine dose is stabilized, then the lamotrigine dose should be maintained for 1 week following discontinuation of the other drug and then reduced by half over 2 weeks in equal decrements each week... 

Enzyme-inducing antiepileptic drugs (e.g., carbamazepine, phenobarbital, phenytoin, primidone) may increase the clearance ot lamotrigine and lower its plasma levels... 

With phenytoin, carbamazepine, phenobarbital, primidone, and lamotrigine, hepatotoxicity usually occurs as part of a hypersensitivity reaction, with skin rashes and fever in the early weeks of treatment. More rarely, hepatic disease can develop after many years without signs of hypersensitivity. Once hepatotoxicity develops, mortality... 

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... 

Valproate Carbamazepine epoxide Diazepam Felbamate Lamotrigine Phenobarbital Risk of toxicity, particularly with phenobarbital including primidone-derived phenobarbital and lamotrigine Inhibition of metabolism of the affected drug. Valproate also displaces diazepam from protein binding sites, affecting relation between total diazepam concentration and effect... 

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

To date, among the newer-generation agents, only lamotrigine and oxcarbazepine have received Food and Drug Administration (FDA) approval for use as monotherapy in patients with partial seizures. Phenobarbital and primidone are also useful in partial... 

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... 

Patients already taking antiseizure drugs that induce hepatic enzymes fe.g., carbamazepine, phenytoin, phenobarbital, or primidone) should be given lamotrigine initially at 50 mg/day for 2 weeks. The dose is increased to 50 mg twice per day fori weeks and then increased in increments of 100 mg/day each week up to a maintenance dose of 300—500 mg/day divided into two doses. For patients taking valproic acid in addition to an enzyme-inducing antiseizure drug, the initial dose should be 25 mg every other day for 2 weeks, followed by an increase to 25 mg/day for 2 weeks the dose then can be increased by 25-50 mg/day every 1-2 weeks up to a maintenance dose of 100—150 mg/day divided into two doses. 

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