Palifren Long (Paliperidone)

Paliperidone is indicated for the management of schizophrenia, a chronic psychotic disorder affecting thought, perception and behavior.

• Schizophrenia: Reduces risk of relapse and helps maintain symptom control when used as a long‑acting injection.
• Schizoaffective disorder: Provides sustained antipsychotic coverage to stabilize mood and psychotic symptoms.
• Bipolar I disorder (maintenance): Offers adjunctive long‑term control of manic episodes when other therapies are insufficient.

• Paliperidone acts as a potent antagonist at dopamine D2 and serotonin 5‑HT2A receptors, modulating neurotransmission linked to psychosis. It also exhibits moderate affinity for α‑adrenergic and histamine H1 receptors, contributing to its overall clinical profile. The long‑acting formulation releases the drug slowly from the intramuscular depot, maintaining therapeutic plasma concentrations over several weeks.

Palifren Long may cause a range of adverse reactions, which vary in frequency and severity.

Common Side Effects

• Injection site pain or erythema
• Headache
• Dizziness or light‑headedness
• Fatigue
• Nausea
• Restlessness (akathisia)

Serious or Rare Side Effects

• Neuroleptic malignant syndrome
• Tardive dyskinesia
• Severe orthostatic hypotension
• Hyperglycaemia or new‑onset diabetes
• Seizures
• Elevated prolactin leading to galactorrhoea or menstrual disturbances

When prescribing Palifren Long, clinicians should assess patient history and monitor for specific safety concerns.

• Cardiovascular assessment: Evaluate for QT‑interval prolongation and orthostatic hypotension.
• Metabolic monitoring: Check blood glucose and lipid profiles periodically.
• Movement disorders: Observe for signs of tardive dyskinesia or akathisia.
• Hormonal effects: Monitor prolactin levels, especially in women of childbearing age.
• Pregnancy and lactation: Use only if benefits outweigh potential risks.
• Store at ambient temperature: keep in original packaging, protect from moisture and direct sunlight.

Palifren Long can interact with several medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole): may increase paliperidone exposure.
• Strong CYP3A4 inducers (e.g., carbamazepine, rifampicin): may reduce therapeutic levels.
• QT‑prolonging agents (e.g., certain antiarrhythmics, macrolide antibiotics): increase risk of cardiac arrhythmias.

Moderate Interactions (Monitor Closely)

• Antihypertensives: additive orthostatic hypotension.
• CNS depressants (e.g., benzodiazepines, opioids): enhanced sedation.
• Anticholinergic drugs: may worsen cognitive side effects.
• Lithium: potential for increased neuro‑toxic effects.
• NSAIDs: may raise risk of bleeding when combined with anticoagulants.