Fluphenazine decanoate (“Prolixin Dec”) is one of the first-generation antipsychotics long-acting antipsychotics available in the United States.
Fluphenazine Decanoate | |
Indication(s) | Schizophrenia |
Dosing available as prefilled syringes | Prolixin Dec is directly drawn up from a 5 ml vial with a 25 mg/ml concentration that can be stored after each use and used until empty. |
Recommended starting and maintenance dose | In patients new to Prolixin Dec, dose titration can be used but is not required. Initiate with 6.25 mg IM, followed dose adjustments in between 6.25 to 12.5 mg increments every two weeks until the target dose is reached. If using dose titration, overlap with oral fluphenazine for one to two months while building up Prolixin Dec. |
Drug Metabolizing Enzyme | CYP2D6 |
Loading dose | Not established |
Oral overlap | There is no exact formulary for oral to IM conversion. 10 mg fluphenazine daily corresponds to Prolixin Dec 12.5 IM every three weeks. The highest individual dose is listed in the package insert as 100 mg IM (but see below). Patient response should always be the indicator of appropriate dosing. |
Establishing tolerability | Prior to initiating Prolixin Dec, establish tolerability with oral fluphenazine in fluphenazine-naïve patients. |
Storage | Room temperature |
Reconstitution or mixing | N/A |
Injection site | Deltoid or gluteal injections are both possible; the site can be chosen based on patient preference and body habitus. Alternate sites and use 1-inch needle for deltoid, 2-inch needle for gluteal injection. |
Injection interval | Prolixin Dec is typically given IM every two weeks; there is, however, flexibility around the injection interval and injections up to every 6 weeks have been used. |
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 | Prolixin Dec is oil-based (sesame oil) which is more painful than water-based long-acting injectables. You also will need to push harder. Avoid giving more than 3 cc as a single injection. |
When a dose is missed | For those patients who are scheduled to receive Prolixin Decanoate injections every 4 weeks and who have received at least two previous injections as scheduled, the next dose should be administered not later than 8 weeks after the last injection. For more information review this tip. |
REMS | No |
Additional information | Sesame oil base - check for sesame allergy. |
Dose Conversion of Oral Fluphenazine to Fluphenazine Decanoate LAI | |
PO Dose - Fluphenazine | LAI/IM Dose - Fluphenazine Decanoate |
Initial LAI dose | Suggested 6.25 mg every 2 weeks |
10 mg daily | 12.5 mg (0.5 ml) every 3 weeks |
20 mg daily | 25 mg (1 ml) every 3 weeks |
30 mg daily | 37.5 mg (1.5 ml) every 3-6 weeks |
40 mg daily | 50 mg (2 ml) every 3-6 weeks |
Typical dose: 6.25-25 mg every 2-4 weeks. | |
Practical issues (including administration)
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.