No, Thorazine (chlorpromazine) does not have a long-acting injectable (LAI) formulation available.
Chlorpromazine is only available as an immediate-acting intramuscular injection and oral formulations, not as a long-acting injectable antipsychotic. 1
Available Formulations
The FDA-approved chlorpromazine injectable formulation is:
- Immediate-acting IM injection: 25 mg/mL in 1 mL and 2 mL ampules 1
- Intended for deep intramuscular use for acute management
- Onset occurs within minutes to 30 minutes, not the weeks-to-months duration characteristic of LAI formulations 2
Context: LAI Antipsychotics
While chlorpromazine lacks an LAI formulation, several other antipsychotics are available as LAIs:
First-generation LAIs:
Second-generation LAIs:
- Paliperidone palmitate (monthly and 3-monthly formulations)
- Aripiprazole monohydrate (monthly)
- Aripiprazole lauroxil (monthly, 6-week, and 8-week formulations)
- Olanzapine pamoate (monthly)
- Risperidone microspheres (monthly) 3, 5, 6
Clinical Implications
LAI antipsychotics provide sustained drug release for weeks to months and are recommended as first-line maintenance treatment for schizophrenia and schizoaffective disorder 4, 6. They significantly reduce 30-day psychiatric readmission rates compared to oral antipsychotics (1.9% vs 8.3%, p=0.03) 7.
Guidelines recommend that LAI formulations should be systematically offered to patients requiring long-term antipsychotic treatment, particularly after first-episode psychosis 8, 4, 6. The optimal definition of treatment-resistant schizophrenia includes at least one failed trial with an LAI antipsychotic given for at least 6 weeks after achieving steady state 9.
If you need an LAI antipsychotic, you must select from the available LAI formulations listed above—chlorpromazine cannot fulfill this role.