Some information presented within this Center of Excellence was created in collaboration with the California Department of State Hospitals (DSH). This includes that the content has been specifically aligned to the DSH’s medication guidelines (DSH Psychotropic Medication Operational Procedures, appended to DSH Policy Directive 3400). These medication guidelines are applicable only to the DSH settings and inclusion within this resource does not indicate that they must be followed in any non-DSH settings. The medication guidelines included in this resource are those of DSH and do not necessarily represent the views, policy(ies), and/or position(s) of the American Psychiatric Association (APA).
Haloperidol Decanoate | |
Indication(s) | Schizophrenia |
Dosing available as prefilled syringes | 50mg/mL and 100mg/mL vial concentration available. |
Recommended loading doses | A standard loading regimen will be 10 x the oral daily dose weekly x 3 |
Recommended maintenance dose | A standard maintenance regimen will be 20 x the oral daily dose every 4 weeks beginning 2 weeks after the last loading dose. (e.g., haloperidol 10 mg daily corresponds to haloperidol decanoate 200 mg every 4 weeks). Highest recommended maintenance dose is 600 mg every 4 weeks, note > 300 mg every 4 weeks should be divided into 2-week intervals. Therapeutic drug monitoring (TDM) can guide dosing. A trough haloperidol plasma level between 2 and 18 ng/ml is a therapeutic target. |
Oral overlap | Continue half the oral dose until the second loading dose injection |
Drug metabolizing enzyme | CYP2D6, CYP3A4, CYP1A2 |
Establishing tolerability | Prior to initiating haloperidol decanoate, establish tolerability with either oral or immediate-release IM haloperidol in haloperidol-naïve patients. Use anticholinergic medications only to rescue acute dystonia or parkinsonism, treat ongoing dystonia or parkinsonism with amantadine. |
Storage | Room temperature. Haloperidol decanoate is directly drawn up from vial that can be stored after each use and used until empty. |
Reconstitution or mixing | 50mg/mL and 100mg/mL vial concentration available. |
Injection site | Deltoid or gluteal injections are both possible; the site can be chosen based on patient preference. Alternate sites and use appropriate needles for deep intramuscular injection. Do not inject more than 3 cc volume per injection site. |
Injection interval | Haloperidol decanoate is typically given IM every four weeks. Doses > 300 mg should be divided and given at a 2-week interval. Reducing the injection interval (rather than increasing the individual dose) can be used to increase steady state haloperidol plasma levels. |
Preparation | As this is a sesame oil vehicle, it may be pulled out of vial with a larger gauge needle (i.e. 18 gauge) then injected with a new, smaller gauge needle (i.e. 21 gauge) for patient comfort |
Administration considerations | Haloperidol decanoate is oil-based, which is more painful than water-based long-acting injectables. You also will need to push harder. Be careful to select the correct concentration: haloperidol decanoate is available as 50 mg/cc and as 100 mg/cc. Consider only using one concentration in your clinic to avoid dosing mistakes. |
When a dose is missed | If a maintenance dose is missed, the next maintenance dose must be given within 6 weeks, if > than 6 weeks, reload haloperidol decanoate using 2 or 3 loading doses depending on plasma concentration. |
REMS | No |
Additional information | Sesame oil base - check for sesame allergy. |
Dose Conversion of Oral Haloperidol to Haloperidol Decanoate LAI | |
Oral Dose - Haloperidol | LAI/IM Dose - Haloperidol Decanoate |
Initiate LAI dose | 10x PO dose for 3 weeks |
Maintenance LAI dose | 20 x PO dose every 4 weeks, beginning 2 weeks after last loading dose |
Recommended available dose formulations include 50 mg/ml strength, in 3 ml multiple dose vials or 100 mg/ml strength, in 5 ml multiple dose vials. Dose reduction may be necessary for CYP450 interactions or side effect intolerance. References: 1. Janssen Pharmaceuticals. (2019). Haloperidol decanoate for IM injection only. 2. HALDOL DECANOATE USPI 3. DSH Psychotropic Medication Operational Procedures. (2025). Chapter 9. 4. Meyer, Jonathan M., and Stephen M. Stahl. The clinical use of antipsychotic plasma levels: stahl's handbooks. Cambridge University Press, 2021. | |
For more information, download this fact sheet developed by the DSH Psychopharmacology Resource Network (PRN).
FDA Medication Label
Information on this topic is found in the FDA medication label. Not all information in the FDA medication label is included here, and clinicians should read the entire FDA medication label before making treatment decisions.
Prescribing should always be informed by the FDA medication label. Medication labels can be found by searching Drugs@FDA at the FDA website. Labels are also available using the Drugs@FDA app for Apple or Android devices.
Labels change over time, and the current label should always be consulted. Here is the most recent label, at time of writing.