Paliperidone ER

SGA / Active Metabolite·Psychiatry - Oral Antipsychotics

Schizophrenia, Schizoaffective disorder

Authority requiredPBSSGAInvega9 mg tablet+2

Max Dose

12 mg/day

Half-life

23 h

Prolactin

HIGH RISK

Ghost Pill

IN STOOL

Rapid Summary

Overview

The primary active metabolite of Risperidone (9-hydroxyrisperidone). Formulated in an advanced OROS osmotic pump tablet. Bypasses liver CYP2D6 metabolism entirely.

Maximum Dose

Max 12 mg/day.

Clinical Focus

Causes intense hyperprolactinemia. The tablet shell does not dissolve; warn the patient they will see the intact pill in their feces.

Bottom Line

Paliperidone ER is the active metabolite of risperidone in oral extended-release form with fewer drug interactions, but causes significant hyperprolactinaemia and the shell may appear in stool.

Formulation & Access

Brand Names

Invega

Oral Routes

Extended Release OROS Tablets (3, 6, 9 mg). MUST be swallowed whole. Never crush or chew.

Prescribing & PBS

Authority Required (PBS).

Indications & Use

Primary

PBSTGA

Schizophrenia, Schizoaffective disorder.

Clinical Place

Often used as the oral tolerance test before initiating the highly popular Invega Sustenna (LAI depot) injections, or in patients who lack the liver enzyme (CYP2D6) to process Risperidone.

Quick reference

Class & Role

SGA / Active Metabolite — The primary active metabolite of Risperidone (9-hydroxyrisperidone).

Route / Formulation

Extended Release OROS Tablets (3, 6, 9 mg). MUST be swallowed whole. Never crush or chew. (Invega)

Usual Dose & Max

PO 3-6 mg OD (morning). May increase to Max 12 mg/day.

Key Indication Doses

Schizophrenia: PO 3-6 mg OD (morning). May increase to Max 12 mg/day. Schizoaffective Disorder: PO 6 mg OD. Renal Impairment: If eGFR 50-80, Max 6 mg/day. If eGFR 10-50, Max 3 mg/day. Avoid if < 10.

Best Uses

Paliperidone ER is the active metabolite of risperidone in oral extended-release form with fewer drug interactions, but causes significant hyperprolactinaemia and the shell may appear in stool.

Avoid / Cautions

Severe renal impairment, mechanical bowel obstruction.

Key Risks

Endocrine: Severe hyperprolactinemia (galactorrhea, amenorrhea, sexual dysfunction). Neurological: Extrapyramidal side effects (EPS), akathisia, tachycardia (reflex to alpha-1 blockade). Gastrointestinal: Do not use in patients with severe bowel strictures (the rigid tablet can cause an obstruction).

Key Interactions

Because it is not heavily metabolised by CYP450 enzymes, it avoids the massive drug interactions that plague Risperidone (like Fluoxetine or Paroxetine spiking blood levels).

Monitoring

Check eGFR before initiation. Monitor serum Prolactin if symptoms develop. Inform the patient about the ghost pill in the stool to prevent panic that the drug 'isn't working'.

Clinical Pearl

In a patient with severe liver cirrhosis or taking multiple interacting drugs (like strong SSRIs), regular Risperidone will accumulate and cause severe toxicity. Paliperidone bypasses this by relying on the kidneys, making it much safer in complex hepatic or polypharmacy patients.

Access

Authority requiredInvega9 mg tablet

Brand: Invega
PBS status: Authority required
Formulation: Extended Release OROS Tablets (3, 6, 9 mg)

Paliperidone ER

SGA / Active Metabolite·Psychiatry - Oral Antipsychotics

Schizophrenia, Schizoaffective disorder

Authority requiredPBSSGAInvega9 mg tablet+2

Max Dose

12 mg/day

Half-life

23 h

Prolactin

HIGH RISK

Ghost Pill

IN STOOL

Rapid Summary

Overview

The primary active metabolite of Risperidone (9-hydroxyrisperidone). Formulated in an advanced OROS osmotic pump tablet. Bypasses liver CYP2D6 metabolism entirely.

Maximum Dose

Max 12 mg/day.

Clinical Focus

Causes intense hyperprolactinemia. The tablet shell does not dissolve; warn the patient they will see the intact pill in their feces.

Bottom Line

Paliperidone ER is the active metabolite of risperidone in oral extended-release form with fewer drug interactions, but causes significant hyperprolactinaemia and the shell may appear in stool.

Formulation & Access

Brand Names

Invega

Oral Routes

Extended Release OROS Tablets (3, 6, 9 mg). MUST be swallowed whole. Never crush or chew.

Prescribing & PBS

Authority Required (PBS).

Indications & Use

Primary

PBSTGA

Schizophrenia, Schizoaffective disorder.

Clinical Place

Often used as the oral tolerance test before initiating the highly popular Invega Sustenna (LAI depot) injections, or in patients who lack the liver enzyme (CYP2D6) to process Risperidone.

Quick reference

Class & Role

SGA / Active Metabolite — The primary active metabolite of Risperidone (9-hydroxyrisperidone).

Route / Formulation

Extended Release OROS Tablets (3, 6, 9 mg). MUST be swallowed whole. Never crush or chew. (Invega)

Usual Dose & Max

PO 3-6 mg OD (morning). May increase to Max 12 mg/day.

Key Indication Doses

Schizophrenia: PO 3-6 mg OD (morning). May increase to Max 12 mg/day. Schizoaffective Disorder: PO 6 mg OD. Renal Impairment: If eGFR 50-80, Max 6 mg/day. If eGFR 10-50, Max 3 mg/day. Avoid if < 10.

Best Uses

Paliperidone ER is the active metabolite of risperidone in oral extended-release form with fewer drug interactions, but causes significant hyperprolactinaemia and the shell may appear in stool.

Avoid / Cautions

Severe renal impairment, mechanical bowel obstruction.

Key Risks

Key Interactions

Because it is not heavily metabolised by CYP450 enzymes, it avoids the massive drug interactions that plague Risperidone (like Fluoxetine or Paroxetine spiking blood levels).

Monitoring

Check eGFR before initiation. Monitor serum Prolactin if symptoms develop. Inform the patient about the ghost pill in the stool to prevent panic that the drug 'isn't working'.

Clinical Pearl

Access

Authority requiredInvega9 mg tablet

Brand: Invega
PBS status: Authority required
Formulation: Extended Release OROS Tablets (3, 6, 9 mg)