When transitioning a patient from risperidone oral to paliperidone palmitate (Invega Sustenna), information on the manufacturer’s current website states that all patients transitioning from oral antipsychotics must follow the recommended initiation dosing of 234 mg (day 1), 156 mg (day 8), both administered in the deltoid muscle. No oral supplementation is required.
The paliperidone palmitate label does not specifically address conversion of risperidone tablets to paliperidone palmitate. Patients stabilized on risperidone tablets can attain similar steady-state exposure with INVEGA SUSTENNA® as depicted in Table. The INVEGA SUSTENNA® Prescribing Information does not specifically address conversion of RISPERDAL® tablets to INVEGA SUSTENNA®. This information is based on pharmacokinetic (PK) modeling performed to compare steady-state exposure during maintenance treatment between RISPERDAL® tablets and INVEGA SUSTENNA® (after both the 234 mg/156 mg deltoid starting doses):
The patient’s third injection will be at the maintenance dose designated by their clinician, either 117 mg, 156 mg, or 234 mg.
Paliperidone is OH-risperidone, the active metabolite of risperidone, which explains the drugs’ similarities, as well as ability to establish tolerance by using either oral risperidone or paliperidone.
FDA medication label
Information on this topic is found in the FDA medication label. Here is the most recent label, at time of writing. 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.