For more than a decade, the standard way to start someone on a long-acting injectable form of paliperidone has involved two injections in the first week — a "loading dose" strategy. Erzofri, FDA-approved in 2024, changes that. It is a new paliperidone palmitate formulation designed to reach therapeutic blood levels with a single starting injection, eliminating the second loading dose and the brief period of oral supplementation that some patients required.
Erzofri is a long-acting injectable form of paliperidone palmitate approved for schizophrenia and schizoaffective disorder, dosed monthly with a single starting injection rather than the two-dose loading regimen used by Invega Sustenna.
What it is
Erzofri (paliperidone palmitate extended-release injectable suspension) is a reformulation of paliperidone, the active metabolite of risperidone. It is given by deep intramuscular injection, slowly releasing paliperidone over a month. Erzofri is FDA-approved for adults with schizophrenia or schizoaffective disorder.
The other major paliperidone palmitate products in this family include Invega Sustenna (monthly), Invega Trinza (every three months), and Invega Hafyera (every six months). Erzofri is distinct from these — it is not the same product as Invega Sustenna with a different name.
The loading-dose problem Erzofri solves
Standard Invega Sustenna initiation involves two injections one week apart (typically 234 mg on day 1 and 156 mg on day 8), both into the deltoid muscle. The two-injection start was developed to bring blood levels up quickly enough to provide therapeutic coverage. It works, but it has costs:
- The patient has to come back to the clinic within a week
- For inpatients being discharged, scheduling that second injection can be difficult
- For outpatients, a missed second injection blunts the entire initiation
- Each injection has its own discomfort and logistical burden
Erzofri's formulation produces useful paliperidone levels from a single first injection, meaning the next injection is not needed for about a month. According to the FDA-approved label, no oral antipsychotic supplementation is required.
Dosing
Initiation: a single 351 mg or 471 mg deltoid intramuscular injection, depending on the desired maintenance dose. Maintenance: monthly injections of 78 mg, 117 mg, 156 mg, 234 mg, or 312 mg into the deltoid or gluteal muscle.
For patients switching from oral paliperidone or oral risperidone, the prescriber selects the maintenance dose based on the prior oral regimen and clinical response. Final dose decisions belong to the prescriber.
Effectiveness
Paliperidone palmitate as a class has strong evidence for relapse prevention in schizophrenia, including the well-known PRIDE study showing reduced rates of treatment failure in patients with criminal-justice involvement when switched from oral antipsychotics to paliperidone palmitate (Alphs et al., J Clin Psychiatry 2015). Erzofri's pivotal trial demonstrated that the new formulation produces the pharmacokinetic exposure needed for the same clinical effect, allowing FDA approval based on bioequivalence rather than a separate efficacy trial.
Side effects
Side effects are essentially those of paliperidone:
- Hyperprolactinemia — paliperidone, like risperidone, raises prolactin substantially in most patients
- Weight gain — moderate
- Sedation
- Akathisia
- Extrapyramidal symptoms — particularly at higher doses
- Injection-site reactions — pain, induration, redness
- Orthostatic hypotension
You develop high fever with muscle rigidity, severe muscle spasms, persistent involuntary movements, or signs of an allergic reaction. Severe injection-site infection (worsening redness, drainage, fever) also warrants prompt evaluation.
Who Erzofri fits well
- People who would benefit from paliperidone palmitate but for whom a two-injection start is impractical
- Inpatients being discharged who would not reliably return for a day-8 loading dose
- People who prefer a simpler initiation regimen
- Patients with schizoaffective disorder seeking an LAI option (Erzofri is approved for both schizophrenia and schizoaffective disorder)
Who might choose differently
- People with significant prolactin-related symptoms on paliperidone or risperidone
- People who want a longer dosing interval (Invega Trinza or Invega Hafyera)
- People whose insurance only covers older paliperidone formulations
Monitoring
- Baseline weight, fasting glucose, lipids; repeat at 3, 6, and 12 months
- Prolactin if symptoms suggest hyperprolactinemia
- AIMS at baseline and every 6 months
- Blood pressure during the first months, particularly with dose adjustments
Practical questions to ask
- Why Erzofri instead of Invega Sustenna or Trinza?
- What dose are we starting at, and what maintenance dose are we aiming for?
- Is gluteal or deltoid injection planned for maintenance?
- How will we manage prolactin and metabolic side effects?
- What if I miss an appointment?
This article is for educational purposes only and is not medical advice. Information is summarised from publicly available FDA labelling and peer-reviewed sources. Always consult your prescribing clinician before starting, stopping, or changing any medication.