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Perseris Dosage

Medically reviewed by Last updated on Dec 8, 2021.

Generic name: Risperidone 90mg in 0.6mL;
Dosage form: extended-release injectable suspension

Recommended Dosage

PERSERIS is to be administered as an abdominal subcutaneous injection only. Do not administer by any other route.

Each injection must be administered by a healthcare professional using the prepackaged injection syringe and enclosed safety needle [see Dosage and Administration (2.4)].

For patients who have never taken risperidone, establish tolerability with oral risperidone prior to starting PERSERIS.

Initiate PERSERIS at a dose of 90 mg or 120 mg once monthly by subcutaneous injection. Do not administer more than one dose (90 mg or 120 mg total) per month.

Based on average plasma concentrations (Cavg) of risperidone and total active moiety, PERSERIS 90 mg corresponds to 3 mg/day oral risperidone and PERSERIS 120 mg corresponds to 4 mg/day oral risperidone. Patients who are on stable oral risperidone doses lower than 3 mg/day or higher than 4 mg/day may not be candidates for PERSERIS [see Clinical Pharmacology (12.3) and Clinical Studies (14)].

Neither a loading dose nor any supplemental oral risperidone is recommended. A patient who misses a dose should receive the next dose as soon as possible.

Dosage Recommendations for Patients with Renal or Hepatic Impairment

PERSERIS has not been studied in patients with renal or hepatic impairment and should be used with caution in these special populations. Prior to initiating treatment with PERSERIS in these patients, it is advisable that patients be carefully titrated up to at least 3 mg daily of oral risperidone. If patients can tolerate 3 mg of oral risperidone and are psychiatrically stable, a dose of PERSERIS 90 mg may be considered [see Use in Specific Populations (8.6, 8.7) and Clinical Pharmacology (12.3)].

Dosage Recommendations for Concomitant Use with Strong CYP2D6 Inhibitors and Strong CYP3A4 Inducers

Co-administration with Strong CYP2D6 Inhibitors

When initiation of fluoxetine or paroxetine is considered, patients may be placed on the lowest dose (90 mg) of PERSERIS between 2- to 4-weeks before the planned start of fluoxetine or paroxetine therapy to adjust for the expected increase in plasma concentrations of risperidone.

When fluoxetine or paroxetine is initiated in patients receiving PERSERIS 90 mg, it is recommended to continue treatment with 90 mg unless clinical judgment necessitates interruption of PERSERIS treatment [see Drug Interactions (7.1)].

Co-administration with Strong CYP3A4 Inducers

At the initiation of therapy with carbamazepine or other known hepatic enzyme inducers, patients should be closely monitored during the first 4- to 8-weeks. In patients receiving PERSERIS 90 mg, consider increasing the dose to 120 mg. In patients receiving PERSERIS 120 mg, additional oral risperidone therapy may need to be considered.

On discontinuation of carbamazepine or other strong CYP3A4 hepatic enzyme inducers, the dosage of PERSERIS or any additional oral risperidone therapy should be re-evaluated and, if necessary, decreased to adjust for the expected increase in plasma concentration of risperidone.

For patients treated with PERSERIS 90 mg and discontinuing from carbamazepine or other strong CYP3A4 enzyme inducers, it is recommended to continue treatment with the 90 mg dose unless clinical judgment necessitates interruption of PERSERIS treatment [see Drug Interactions (7.1)].

Instructions for Use

Important Information

  • For abdominal subcutaneous injection, only. Do not administer by any other route.
  • To be administered by a healthcare professional only.
  • Please read the instructions carefully before handling this product.
  • Allow package to come to room temperature for at least 15 minutes prior to preparation.
  • Only prepare medication when you are ready to administer the dose.
  • As a universal precaution, always wear gloves.


See Figure 1

  • One Liquid Syringe (Figure
) prefilled with the delivery system. Inspect liquid solution for foreign particles. This is the syringe you will use to inject the patient.

  • One Powder Syringe (Figure
) prefilled with Risperidone powder. Inspect syringe for consistency of powder color and for foreign particles.

  • One sterile 18-gauge, 5/8-inch safety needle.

Parenteral drug products should always be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

Figure 1

Figure 1


See Figure 2

Hold the Powder Syringe upright and tap the barrel of the syringe to dislodge the packed powder.

NOTE: Powder can become packed during shipping.

Figure 2

Figure 2


See Figure 3

Remove the cap from the Liquid Syringe, then remove the cap from the Powder Syringe.

Holding both syringes in your non-dominant hand can help with this step.

Figure 3

Figure 3


See Figure 4

Place the Liquid Syringe on top of the Powder Syringe (to prevent powder spillage) and connect the syringes by twisting approximately ¾ turn.

Do not over tighten.

Keep your fingers off the plungers during this step to avoid spillage of the medication.

Figure 4

Figure 4


See Figure 5

Failure to fully mix the medication could result in incorrect dosage.

Figure 5

Figure 5


  • Transfer the contents of the Liquid Syringe into the Powder Syringe.
  • Gently push the Powder Syringe plunger until you feel resistance (to wet powder and avoid compacting).
  • Repeat this gentle back-and-forth process for 5 cycles.

Complete mixing

  • Continue mixing the syringes for an additional 55 cycles.
  • This mixing can be more vigorous than when premixing.
  • Figure 5 illustrates a correct full cycle.

When fully mixed, the product should be a cloudy suspension that is uniform in color. It can vary from white to yellow-green in color. If you see any clear areas in the mixture, continue to mix until the distribution of the color is uniform. The product is designed to deliver risperidone 90 mg or 120 mg.


See Figure 6

Failure to aspirate the liquid from the Powder Syringe may result in incorrect dosage.

  • First, transfer all contents into the Liquid Syringe.
  • Next, perform the following actions SIMULTANEOUSLY:
    • maintain slight pressure on the Powder Syringe plunger and
    • pull back gently on the Liquid Syringe plunger while twisting the syringes apart.
  • Finally, attach the safety needle by twisting until finger tight.

Check that medication is uniform in color and free from foreign particles.

Figure 6

Figure 6


See Figure 7

Choose an injection site on the abdomen with adequate subcutaneous tissue that is free of skin conditions (e.g., nodules, lesions, excessive pigment). It is recommended that the patient is in the supine position.

Do not inject into an area where the skin is irritated, reddened, bruised, infected or scarred in any way.

Clean the injection site well with an alcohol pad.

To help minimize irritation, rotate injection sites following a pattern similar to the illustration (Figure 7).

Figure 7

Figure 7


See Figure 8

Hold the syringe upright for several seconds to allow air bubbles to rise.

Remove needle cover and slowly depress the plunger to push out the excess air from the syringe.

If medication is seen at the needle tip, pull back slightly on the plunger to prevent medication spillage.

Due to the viscous nature of the medication, bubbles will not rise as quickly as those in an aqueous solution.

Figure 8

Figure 8


See Figure 9

Pinch the skin around the injection area. Be sure to pinch enough skin to accommodate the size of the needle. Lift the adipose tissue from the underlying muscle to prevent accidental intramuscular injection.

Figure 9

Figure 9


See Figure 10

Insert needle fully into the subcutaneous tissue.

Inject the medication slow and steady.

PERSERIS is for subcutaneous administration only. Do not inject by any other route.

NOTE: Actual angle of injection will depend on the amount of subcutaneous tissue.

Figure 10

Figure 10


See Figure 11

Withdraw the needle at the same angle used for insertion and release pinched skin.

Do not rub the injection area after the injection. If there is bleeding, apply a gauze pad or bandage but use minimal pressure.

Figure 11

Figure 11


See Figure 12

Lock the needle guard into place by pushing it against a hard surface such as a table.

Dispose of all syringe components in a secure sharps disposal container.

Figure 12

Figure 12


See Figure 13

Advise the patient that they may have a lump for several weeks that will decrease in size over time. It is important that the patient not rub or massage the injection site and to be aware of the placement of any belts or clothing waistbands.

Figure 13

Figure 13

Frequently asked questions

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.