Which atypical antipsychotics can be administered intravenously (IV)?

From the Guidelines

Currently, there are no atypical antipsychotics approved for intravenous (IV) administration in routine clinical practice. All second-generation (atypical) antipsychotics are available only in oral formulations (tablets, capsules, orally disintegrating tablets, or oral solutions) or as intramuscular (IM) injections. The atypical antipsychotics that have IM formulations include olanzapine, ziprasidone, aripiprazole, and paliperidone palmitate, but these are specifically designed for intramuscular use, not intravenous administration. IV administration of these medications has not been studied extensively for safety and efficacy, and there are concerns about potential cardiovascular effects, including QT prolongation and hypotension, that could be exacerbated by the rapid drug delivery that occurs with IV administration 1.

Some key points to consider when evaluating the use of antipsychotics include:

• The risk of QT prolongation associated with certain antipsychotics, such as thioridazine and ziprasidone 1
• The potential for extrapyramidal symptoms, such as acute dystonia, akathisia, and Parkinsonian syndrome, particularly with typical antipsychotics 1
• The risk of metabolic adverse effects, such as weight gain and hyperglycemia, associated with certain atypical antipsychotics 1
• The importance of careful dosing and monitoring, particularly in older or frail patients, to minimize the risk of adverse effects 1

In emergency situations requiring rapid tranquilization, clinicians typically use conventional antipsychotics like haloperidol (sometimes combined with benzodiazepines) when IV administration is necessary, though even this practice varies by institution and is not universally recommended due to safety concerns 1. Haloperidol is the only antipsychotic that can be given intravenously, but its use is associated with a risk of QT prolongation and other cardiovascular effects, and should be used with caution and careful monitoring.

From the FDA Drug Label

Ziprasidone mesylate for injection as an intramuscular injection is indicated for the: • Acute treatment of agitation in schizophrenic patients.

DOSAGE AND ADMINISTRATION Acute treatment of agitation associated with schizophrenia (intramuscular administration): 10 mg - 20 mg up to a maximum dose of 40 mg per day.

Olanzapine for Injection is intended for intramuscular use only. Each vial provides for the administration of 10 mg (32 μmol) olanzapine with inactive ingredients 50 mg lactose monohydrate and 3.5 mg tartaric acid.

The atypical antipsychotics that can be administered intramuscularly are:

• Ziprasidone 2
• Olanzapine 3

However, the question asks for intravenous (IV) administration. The provided drug labels do not support the use of these atypical antipsychotics via the IV route.

From the Research

Atypical Antipsychotics Administered Intravenously

• Olanzapine can be administered intravenously (IV) 4, 5
• There is limited information available on the IV administration of other atypical antipsychotics, such as ziprasidone, risperidone, and quetiapine
• The available evidence suggests that olanzapine is the most commonly used atypical antipsychotic for IV administration, particularly in cases of acute agitation or severe psychotic episodes 4, 5

Safety and Efficacy of IV Olanzapine

• Studies have shown that IV olanzapine is generally safe and effective for the treatment of acute agitation and psychotic episodes 4, 5
• Common adverse events associated with IV olanzapine include hypotension, bradycardia, and extrapyramidal side effects 4
• The safety and efficacy of IV olanzapine have been evaluated in various patient populations, including those with schizophrenia and schizophrenia-like psychosis 6

Comparison with Other Atypical Antipsychotics

• Olanzapine has been compared to other atypical antipsychotics, such as amisulpride, aripiprazole, clozapine, quetiapine, risperidone, and ziprasidone, in terms of efficacy and tolerability 6
• The results suggest that olanzapine may be more efficacious than some other atypical antipsychotics, but it is also associated with a higher risk of weight gain and metabolic problems 6