Risperidone Lamotrigine

Introduced in clinical practice in the 1960s, lithium was the first mood stabilizer to be used in China. This was followed by carbamazepine and sodium valproate. For many years, these were the only treatment options available as mood stabilizers. Although lamotrigine was approved for maintenance treatment of bipolar I disorder in 2003 by FDA (Food and Drug Administration) in the USA, this indication has not yet been approved by the Chinese authorities. At present, only one atypical antipsychotic drug, risperidone, has been approved for treating acute mania (February 2005 by SFDA [State Food and Drug Administration]) in China (see Table 6.1). 

Lithium, divalproex sodium (valproate), aripiprazole, olanzapine, que-tiapine, risperidone, and ziprasidone are currently approved by the FDA for treatment of acute mania in bipolar disorder. Lithium, olanzapine, and lamotrigine are approved for maintenance treatment of bipolar disorder. Quetiapine is the only antipsychotic that is FDA approved for bipolar depression. 

Another group of mood-stabilizing drugs that are also anticonvulsant agents have become more widely used than lithium. These include carbamazepine and valproic acid for the treatment of acute mania and for prevention of its recurrence. Lamotrigine is approved for prevention of recurrence. Gabapentin, oxcarbazepine, and topiramate are sometimes used to treat bipolar disorder but are not approved by FDA for this indication. Aripiprazole, chlorpromazine, olanzapine, quetiapine, risperidone, and ziprasidone are approved by FDA for the treatment of manic phase of bipolar disorder. Olanzapine plus fluoxetine in combination and quetiapine are approved for the treatment of bipolar depression. 

A 26-year-old woman with bipolar I disorder took lithium and valproate, and sometimes additional risperidone and lamotrigine. Both risperidone and lamo-trigine produced dermatological adverse effects. Her serum lithium concentration was 0.82 mmol/1. Topiramate 75 mg/day was added. A week later, she continued to show a mixed state with mostly manic features and a raised lithium concentration of 1.24 mmol/1. The lithium concentration continued to increase over the next 4 days to 1.97 mmol/1 even though the lithium dosage was reduced from 900 to 750 mg/day. Lithium was withdrawn and the lithium concentration fell. Lithium was then restarted at half the admission dose to achieve a blood concentration of 0.67 mmol/1. Subsequent increases in the dose of topiramate resulted in further increases in the lithium concentration. 

Antidepressants mirtazapine, nefazodone, sertraline Neuroleptics thioridazine, haloperidol, clozapine, quetiapine, risperidone, sertindole, ziprasidone Mood stabilizers carbamazepine, gabapentin, lamotrigine... 

Lithium and valproate are the mainstays of treatment for both acute mania and prophylaxis for recurrent manic and depressive episodes. Anticonvulsants such as lamotrigine, carbamazepine, and oxcarbazepine and atypical antipsy-chotics such as aripizrazole, olanzapine, risperidone, queti-... 

First, initiate and/or optimize mood-stabilizing medication lithium " or valproate or atypical antipsychotic (e.g., olanzapine, quetiapine, risperidone) Alternative anticonvulsants carbamazepine, lamotrigine, or oxcarbazepine... 

Spina W, D Arrigo C, Migliardi G, Santoro V, Muscatello MR, Mico U, D Amico G, Perucca E, Effect of adjunctive lamotrigine treatment on the plasma concentrations of clozapine, risperidone and olanzapine in patients with schizophrenia or bipolar disorder. Ther Drug Monit (2006) 28, 599-602. 

One small study found no interaction between risperidone and lamotrigine, although a case report describes increased risperidone levels on concurrent use, and a retrospective study suggests that lamotrigine increases the variability on risperidone levels. 

Bienentreu SD, Kronmuller K-TH. Increase in risperidone plasma level with lamotrigine. Am J Psychiatry (2005) 162, 811-2. 

Castberg I, Spigset O. Risperidone and lamotrigine no evidence of a drug interaction. J Clin Psychiatry (2006) 67,1159. 

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