Calculation of CPZ Equivalents

We convert all antipsychotic doses to chlorpromazine equivalents, using published equivalencies for oral conventional (American Psychiatric Association 1997) and atypical (Woods 2003) antipsychotics. For depot haloperidol, fluphenazine, and risperidone, we use the manufacturers’ recommended equivalent for the depot to oral conversion for the same drug and then converted to oral chlorpromazine equivalents. For haloperidol the manufacturer recommends that 10-15 mg per 4 weeks is equivalent to 1 mg/d orally. We use the 15 mg figure. This estimate is supported by a bioavailability study (mean 14.1 mg depot/4 weeks per 1 mg/d orally) (Nayak et al 1987). For fluphenazine the manufacturer recommends 12.5 mg depot/3 weeks as equivalent to 10 mg/d orally. This estimate is supported by a dose comparison study (12.5 mg depot/3 week equivalent to approximately 9 mg/d orally) (Schooler and Levine 1976). For risperidone, 25 mg depot/2 weeks per 2 mg/d orally is used (Chue et al 2005).

The following Tables have been created based on the references above.

Table 1. Antipsychotics and Equivalent Doses (sorted by med code) Proposed Code Trade Name Generic Name Equivalent dose 01 Haldol haloperidol 2 mg per day 02 Thorazine chlorpromazine 100 mg per day 03 Mellaril thioridazine 100 mg per day 04 Navane thiothixene 4 mg per day 05 Risperdal risperidone (oral) 2 mg per day 06 Zyprexa olanzapine 5 mg per day 07 Prolixin fluphenazine (oral) 2 mg per day 08 Stelazine trifluoperazine 2 mg per day 09 Trilafon perphenazine 8 mg per day 10 Moban molindone 10 mg per day 11 Loxitane loxapine 10 mg per day 12 Compazine prochlorperazine 15 mg per day 13 Seroquel quetiapine 75 mg per day 13 Serentil mesoridazine 50 mg per day 15 Clozaril clozapine 50 mg per day 17 Geodon ziprasidone 60 mg per day 17 Haldol dec haloperidol (depot) 30 mg per 28 days 18 Prolixin dec fluphenazine (depot) 2.5 mg per 21 days 19 Abilify aripiprazole 7.5 mg per day 20 Risperdal Consta risperidone (depot) 25 mg per 14 days Table 2. Antipsychotics and Equivalent Doses (sorted by trade name) Proposed Code Trade Name Generic Name Equivalent dose 19 Abilify aripiprazole 7.5 mg per day 15 Clozaril clozapine 50 mg per day 12 Compazine prochlorperazine 15 mg per day 17 Geodon ziprasidone 60 mg per day 01 Haldol haloperidol 2 mg per day 17 Haldol dec haloperidol (depot) 30 mg per 28 days 11 Loxitane loxapine 10 mg per day 03 Mellaril thioridazine 100 mg per day 10 Moban molindone 10 mg per day 04 Navane thiothixene 4 mg per day 07 Prolixin fluphenazine (oral) 2 mg per day 18 Prolixin dec fluphenazine (depot) 2.5 mg per 21 days 05 Risperdal risperidone (oral) 2 mg per day 20 Risperdal Consta risperidone (depot) 25 mg per 14 days 13 Serentil mesoridazine 50 mg per day 13 Seroquel quetiapine 75 mg per day 08 Stelazine trifluoperazine 2 mg per day 02 Thorazine chlorpromazine 100 mg per day 09 Trilafon perphenazine 8 mg per day 06 Zyprexa olanzapine 5 mg per day

Table 3. Antipsychotics and Equivalent Doses (sorted by generic name) Proposed Code Trade Name Generic Name Equivalent dose 19 Abilify aripiprazole 7.5 mg per day 02 Thorazine chlorpromazine 100 mg per day 15 Clozaril clozapine 50 mg per day 18 Prolixin dec fluphenazine (depot) 2.5 mg per 21 days 07 Prolixin fluphenazine (oral) 2 mg per day 01 Haldol haloperidol 2 mg per day 17 Haldol dec haloperidol (depot) 30 mg per 28 days 11 Loxitane loxapine 10 mg per day 13 Serentil mesoridazine 50 mg per day 10 Moban molindone 10 mg per day 06 Zyprexa olanzapine 5 mg per day 09 Trilafon perphenazine 8 mg per day 12 Compazine prochlorperazine 15 mg per day 13 Seroquel quetiapine 75 mg per day 20 Risperdal Consta risperidone (depot) 25 mg per 14 days 05 Risperdal risperidone (oral) 2 mg per day 03 Mellaril thioridazine 100 mg per day 04 Navane thiothixene 4 mg per day 08 Stelazine trifluoperazine 2 mg per day 17 Geodon ziprasidone 60 mg per day Table 4. Antipsychotics and Equivalent Doses (sorted by equivalent dose) Proposed Code Trade Name Generic Name Equivalent dose 01 Haldol haloperidol 2 mg per day 05 Risperdal risperidone (oral) 2 mg per day 07 Prolixin fluphenazine (oral) 2 mg per day 08 Stelazine trifluoperazine 2 mg per day 04 Navane thiothixene 4 mg per day 06 Zyprexa olanzapine 5 mg per day 19 Abilify aripiprazole 7.5 mg per day 09 Trilafon perphenazine 8 mg per day 10 Moban molindone 10 mg per day 11 Loxitane loxapine 10 mg per day 12 Compazine prochlorperazine 15 mg per day 13 Serentil mesoridazine 50 mg per day 15 Clozaril clozapine 50 mg per day 17 Geodon ziprasidone 60 mg per day 13 Seroquel quetiapine 75 mg per day 02 Thorazine chlorpromazine 100 mg per day 03 Mellaril thioridazine 100 mg per day 18 Prolixin dec fluphenazine (depot) 2.5 mg per 21 days 17 Haldol dec haloperidol (depot) 30 mg per 28 days 20 Risperdal Consta risperidone (depot) 25 mg per 14 days

References

American Psychiatric Association (1997): Practice Guideline for the Treatment of Patients with Schizophrenia. American Journal of Psychiatry 154:1-63. Chue P, Eerdekens M, Augustyns I, et al (2005): Comparative efficacy and safety of long-acting risperidone and risperidone oral tablets. European Neuropsychopharmacology 15:111-7. Nayak RK, Doose DR, Nair NP (1987): The bioavailability and pharmacokinetics of oral and depot intramuscular haloperidol in schizophrenic patients. J Clin Pharmacol 27:144-50. Schooler NR, Levine J (1976): Initiation of long-term pharmacotherapy in schizophrenia - Dosage and side-effect comparisons between oral and depot fluphenazine. Pharmakopsychiatrie Neuro-Psychopharmakologie 9:159-69. Woods SW (2003): Chlorpromazine equivalent doses for the newer atypical antipsychotics. Journal of Clinical Psychiatry 64:663-667.

Scott W. Woods, M.D. New Haven, Connecticut November 15, 2005 [email protected]