Aripiprazole

Aripiprazole is the most recently approved atypical antipsychotic. This medication has a high affinity for D2 and D3 receptors, as well as 5-HTand 5-HT2a receptors. Although the mechanism of action is not known, aripiprazole may mediate its effects via a combination of partial agonist activity at the D2 and 5-HTj receptors and antagonist activity at the 5-HT2 receptor. 

Aripiprazole has been approved for treatment of schizophrenia and acute manic or mixed episodes in bipolar disorder. This medication is also indicated for maintenance treatment in bipolar I disorder. The recommended starting and target dose for aripiprazole in patients with schizophrenia is 10 or 15 mg/day. This is a once-daily dose, and patients can take the medication with or without food. Although this medication has been shown to be effective in doses ranging from 10 to 30 mg/day, doses higher than 10-15 mg have not been shown to be more effective than 10- to 15-mg doses in patients with schizophrenia. The recommended starting dose for treatment of an acute manic or mixed episode is 30 mg the recommended dose for maintenance treatment in stable patients is 15 mg/day. The elimination half-life is 75 hours, and steady-state concentrations are reached within 2 weeks. Therefore, dose adjustments are recommended every 2 weeks, to allow time for clinical assessments of the medication s effects to be observed at steady-state concentration. Peak plasma concentrations occur within 3-5 hours. At equivalent doses, the plasma concentrations of aripiprazole from the solution were higher compared with plasma concentrations associated with the tablet form. 

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Side Effect Clozapine Risperidone Olanzapine Quetiapine Ziprasidone Aripiprazole Haloperidol... 

Aripiprazole was formulated in the early 1980s to function as a potential dopamine modulator, with both antagonist and agonist activity at the D2 receptor. It is the first D2 partial agonist available for the treatment of schizophrenia and is sometimes referred to as a third-generation antipsychotic. This novel mechanism is... 

Diabetes or family history of diabetes Aripiprazole, quetiapine, ziprasidone Risperidone... 

Hyperlipidemia or significant family history Aripiprazole, ziprasidone Risperidone, quetiapine... 

Current sexual dysfunction or concerns about Aripiprazole, quetiapine, clozapine Olanzapine, ziprasidone... 

Current or past anti-cholinergic side effects Risperidone, quetiapine, aripiprazole ziprasidone Olanzapine (low dose)... 

EPS or severe EPS in the past Quetiapine, aripiprazole, clozapine Ziprasidone... 

Difficulty swallowing tablets/capsules Risperidone or aripiprazole liquid, orally-disintegrating tablets (risperidone, olanzapine, clozapine) Long-acting risperidone... 

Pharmacotherapy is the cornerstone of acute and maintenance treatment of bipolar disorder. Mood-stabilizing drugs are the usual first-choice treatments and include lithium, divalproex, carbamazepine, and lamotrigine. Atypical antipsychotics other than clozapine are also approved for treatment of acute mania. Lithium, lamotrigine, olanzapine, and aripiprazole are approved for maintenance therapy. Drugs used with less research support and without Food and Drug Administration (FDA) approval include topiramate and oxcarbazepine. Benzodiazepines are used adjunctively for mania. 

Mood-stabilizing drugs are considered the primary pharmacotherapy for relapse prevention. Olanzapine and aripiprazole are also approved for maintenance therapy. 

Sprinkle capsule 15, 25 mg Atypical Antipsychotics FDA approved for use in bipolar disorder Aripiprazole Abilify Tablets 5, 10, 15, Dosage should be slowly increased to minimize adverse effects (e.g., 25 mg at bedtime for 1 week, then 25-50 mg/day increments at weekly intervals) 10-30 mg/day once daily acute treatment of mania or mixed episodes due to lack of efficacy used as an adjunctive agent with established mood stabilizers Use as monotherapy or in... 

Olanzapine Zyprexa 20, 30 mg Tablets 2.5, 5, 7.5, 10, 5-20 mg/day in 1 or 2 doses combination with lithium or valproate for the acute treatment of mania or mixed states for bipolar I disorder. Olanzapine and aripiprazole are approved for relapse prevention as well as for acute therapy... 

Conventional antipsychotic drugs such as chlorpromazine and haloperidol have long been used in the treatment of acute mania. More recently, atypical antipsychotic drugs including aripiprazole, olanzapine, quetiapine, risperidone, and ziprasi-done have been approved for the treatment of bipolar mania or mixed mood episodes as monotherapy or in combination with mood-stabilizing drugs.25 Aripiprazole and olanzapine are also approved for maintenance therapy. The combination of olanzapine and fluoxetine is approved for treatment of bipolar depression. Quetiapine is approved for treatment of... 

Risperidone Aripiprazole 2D6 > 3A4 2D6, 3A4 Carbamazepine and phenytoin topiramate hypericum (St. John s Wort). Paroxetine, fluoxetine, sertraline (high dose) grapefruit juice 2D6 or 3A4 substrates acting as competitive inhibitors. 

Aripiprazole shares a similar metabolic profile to risperidone, being metabolized by CYP2D6 and 3A4 (Kubo etal, 2005). Few studies exist to compare and contrast aripiprazole effects in different ethnic groups. A recent study indicated that Chinese... 

Chan, H. Y. etal. (2007). Efficacy and safety of aripiprazole in the acute treatment of schizophrenia in Chinese patients with risperidone as an active control a randomized trial. /. Clin. Psychiatry, 68, 29-36. 

Yokoi, F. et al. (2002). Dopamine D2 and D3 receptor occupancy in normal humans treated with the antipsychotic drug aripiprazole (OPC 14597) a study using positron emission tomography and (llC)raclopride. Neuropsychopharmacology, 27, 248-59. 

Risperidone was launched in China in 1997. Following that, other atypical medication including olanzapine and quetiapine were introduced in the market in 1999 and 2000, respectively. These were followed by the development of generic arip-iprazole and ziprasadone in 2005 and 2006, respectively. Brand-name aripiprazole and ziprasadone will also be launched in 2007 in China. 

Current antipsychotics used to treat patients are divided into two classes the first generation antipsychotics (FGA) or typicals (e.g., chlorproma-zine, haloperidol, thioridazine, and loxapine) and the second generation antipsychotics (SGA) or atypicals (i.e., clozapine, olanzapine, quetiapine, risperidone, aripiprazole, ziprasidone, and asenapine). 

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