Aripiprazole

Brand Names: Aripiprazole

Drug Class: Atypical Antipsychotic

Overview

11 DESCRIPTION Aripiprazole is an atypical antipsychotic drug that is available as Aripiprazole Tablets, USP. Aripiprazole is 7-[4-[4-(2,3-dichlorophenyl)-1-piperazinyl]butoxy]-3,4-dihydrocarbostyril. The empirical formula is C 23 H 27 Cl 2 N 3 O 2 and its molecular weight is 448.38.

Mechanism of Action

12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action The mechanism of action of aripiprazole in schizophrenia is unclear. However, the efficacy of aripiprazole in the listed indications could be mediated through a combination of partial agonist activity at D 2 and 5-HT 1A receptors and antagonist activity at 5-HT 2A receptors. 12.2 Pharmacodynamics Aripiprazole exhibits high affinity for dopamine D 2 and D 3 , serotonin 5-HT 1A and 5-HT 2A receptors (K i values of 0.34 nM, 0.8 nM, 1.7 nM, and 3.4 nM, respectively), moderate affinity for dopamine D 4 , serotonin 5-HT 2C and 5-HT 7 , alpha 1 -adrenergic and histamine H 1 receptors (K i values of 44 nM, 15 nM, 39 nM, 57 nM, and 61 nM, respectively), and moderate affinity for the serotonin reuptake site (K i =98 nM).

Indications

  • 1 INDICATIONS AND USAGE Aripiprazole is indicated for the treatment of: • Schizophrenia • Irritability Associated with Autistic Disorder • Treatment of Tourette’s Disorder Aripiprazole is an atypical antipsychotic. The oral formulations are indicated for: • Schizophrenia (14.1) • Irritability Associated with Autistic Disorder (14.4) • Treatment of Tourette’s disorder (14.5)

Common Doses

  • 15 mg
  • 30 mg
  • 2 mg
  • 10 mg

Dosage

2 DOSAGE AND ADMINISTRATION Initial Dose Recommended Dose Maximum Dose Schizophrenia – adults (2.1) 10 to 15 mg/day 10 to 15 mg/day 30 mg/day Schizophrenia – adolescents (2.1) 2 mg/day 10 mg/day 30 mg/day Irritability associated with autistic disorder – pediatric patients (2.4) 2 mg/day 5 to 10 mg/day 15 mg/day Tourette’s disorder – (2.5) Patients

Black Box Warning

WARNINGS: INCREASED MORTALITY IN ELDERLY PATIENTS WITH DEMENTIA-RELATED PSYCHOSIS AND SUICIDAL THOUGHTS AND BEHAVIOURS WITH ANTIDEPRESSANT DRUGS Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Aripiprazole is not approved for the treatment of patients with dementia-related psychosis [see Warnings and Precautions (5.1)]. Antidepressants increased the risk of suicidal thoughts and behavior in children, adolescents, and young adults in short-term studies.

Contraindications

  • 4 CONTRAINDICATIONS Aripiprazole is contraindicated in patients with a history of a hypersensitivity reaction to aripiprazole. Reactions have ranged from pruritus/urticaria to anaphylaxis [see Adverse Reactions (6.2)]. • Known hypersensitivity to aripiprazole (4)

Side Effects

  • 6 ADVERSE REACTIONS Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The following adverse reactions are discussed in more detail in other sections of the labeling: • Increased Mortality in Elderly Patients with Dementia-Related Psychosis [see Boxed Warning and Warnings and Precautions (5.1)] • Cerebrovascular Adverse Events, Including Stroke [see Warnings and Precautions (5.

Interactions

  • 7 DRUG INTERACTIONS Dosage adjustment due to drug interactions (7.1): Factors Dosage Adjustments for Aripiprazole Known CYP2D6 Poor Metabolizers Administer half of usual dose Known CYP2D6 Poor Metabolizers and strong CYP3A4 inhibitors Administer a quarter of usual dose Strong CYP2D6 or CYP3A4 inhibitors Administer half of usual dose Strong CYP2D6 and CYP3A4 inhibitors Administer a quarter of usual dose Strong CYP3A4 inducers Double usual dose over 1 to 2 weeks 7.