Review Question - QID 103740

Patients with a history of psychosis and medication noncompliance can be treated with a long-acting injectable form of antipsychotic medication. Risperidone, haloperidol decanoate, and fluphenazine are all antipsychotics that are also available in a long-acting, injectable formulation.

Risperidone is an atypical antipsychotic medication that acts at both D2 receptors and serotonin receptors. This class of drugs poses a lower risk for extrapyramidal symptoms and tardive dyskinesia than typical antipsychotics. The atypical antipsychotics commonly cause weight gain or metabolic syndrome, as well as QT interval prolongation. Long-acting injectable formulations of atypical antipsychotics cause similar adverse effects to those seen with oral typical antipsychotics. For patients who respond well to an atypical antipsychotic but are unable to take medication daily, long-acting injectable formulations are an option to ensure better compliance. They are typically administered once per month.

Pacchiarotti et. al review the use of long-acting injectable antipsychotics for the management of bipolar and schizoaffective disorders. They note that patients with psychotic disorders often have issues with medication compliance for a number of reasons. They discuss the risks and benefits of long-acting injectable use in these patients.

Illustration A is a chart showing the various adverse effects of both typical and atypical antipsychotics.

Incorrect Answers:
Answer 1: This patient has been unable to remain compliant with risperidone therapy and has had a worsening of his condition as a result. Therefore, remaining on risperidone with observation would not be appropriate.

Answer 2: Aripiprazole is another atypical antipsychotic that is sometimes used for management of schizophrenia. However, this patient had a good response to risperidone, suggesting that a long-acting formulation of risperidone would be a better first step in management.

Answer 3: Clozapine is an atypical antipsychotic that is associated with potentially life-threatening side effects such as seizures, agranulocytosis, and myocarditis. For this reason, it is typically reserved for patients that have failed therapy with at least two other antipsychotic medications.

Answer 4: Haloperidol is a high potency typical antipsychotic that carriers a higher risk of extrapyramidal symptoms when compared to atypical antipsychotics. For that reason, it is typically not used for the long-term management of schizophrenia.

Bullet Summary:
Patients with schizophrenia that are unable to remain compliant on antipsychotic medication may be switched to a long-acting injectable formulation of antipsychotic medication to improve compliance and better control symptoms.