Palimax ER3 mg

Palimax ER 3 mg is an atypical (second-generation) antipsychotic, the major active metabolite of risperidone. Its evidence-based uses include:

• Established/FDA-approved uses:
  • Treatment of schizophrenia in adults and in adolescents aged 12–17 years (acute treatment and prevention of recurrence).
  • Treatment of schizoaffective disorder in adults, as monotherapy or as an adjunct to mood stabilizers or antidepressants.
• Maintenance/long-term use: Once stabilized, Palimax ER 3 mg (oral extended-release) may be continued for relapse prevention; a long-acting injectable ester of Palimax ER 3 mg (Palimax ER 3 mg palmitate) is also available separately for once-monthly or longer-interval maintenance therapy.
• Off-label use (not FDA-approved, used in some clinical settings): Adjunctive management of treatment-resistant mood symptoms in bipolar disorder; this is not a standard first-line use and should only be undertaken by a specialist.

Palimax ER 3 mg is not approved for treatment of dementia-related psychosis in elderly patients (see Precautions and Warnings for the boxed warning).

Each extended-release (prolonged-release, OROS-technology) film-coated tablet contains Palimax ER 3 mg as the active ingredient, commonly available in strengths of 1.5 mg, 3 mg, 6 mg, and 9 mg. In Bangladesh, Palimax ER 3 mg extended-release tablets are typically marketed in 1.5 mg, 3 mg, and 6 mg strengths.

Palimax ER 3 mg is a benzisoxazole-derivative, second-generation (atypical) antipsychotic and the principal active metabolite of risperidone. It is formulated as an extended-release oral tablet using an osmotic-controlled release (OROS) delivery system, allowing once-daily dosing with a relatively steady plasma concentration over 24 hours. Palimax ER 3 mg is used mainly for schizophrenia and schizoaffective disorder. A long-acting injectable palmitate ester of Palimax ER 3 mg exists for maintenance treatment but is marketed and labeled as a separate generic (Palimax ER 3 mg palmitate).

Palimax ER 3 mg belongs to the atypical (second-generation) antipsychotic class of medicines, specifically a benzisoxazole derivative.

Palimax ER 3 mg acts as a central dopamine D2 receptor antagonist and serotonin 5-HT2A receptor antagonist, a combination believed to improve psychotic symptoms while reducing extrapyramidal effects compared with typical antipsychotics. It also has antagonist activity at alpha-1 and alpha-2 adrenergic receptors and H1 histaminergic receptors, but has little to no affinity for cholinergic muscarinic or beta-adrenergic receptors.

Pharmacokinetics: Oral extended-release Palimax ER 3 mg is released gradually via an OROS osmotic pump tablet, reaching a relatively constant plasma concentration over approximately 24 hours; peak plasma levels occur about 24 hours after dosing. Plasma protein binding is approximately 74%. Palimax ER 3 mg undergoes limited hepatic metabolism (via CYP2D6 and CYP3A4, among other minor pathways) and is eliminated largely unchanged in urine (about 80% of the dose), with an elimination half-life of approximately 23 hours. Because renal excretion is the major elimination pathway, dose adjustment is required in renal impairment.

Palimax ER 3 mg extended-release tablets are for oral use only, once daily, preferably at the same time each day. Tablets must be swallowed whole with liquid and must never be chewed, crushed, or divided, as this would disrupt the controlled-release mechanism. They may be taken with or without food. If a dose is missed, it should generally be taken as soon as remembered unless it is nearly time for the next dose, in which case the missed dose should be skipped — do not double the dose. Any change in dose or discontinuation should be directed by the prescribing physician.

Pregnancy

Palimax ER 3 mg should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus, and only under close medical supervision — do not stop or start Palimax ER 3 mg in pregnancy without consulting a physician. Neonates exposed to antipsychotic drugs, including Palimax ER 3 mg, during the third trimester are at risk of extrapyramidal and/or withdrawal symptoms after delivery (agitation, abnormal muscle tone, tremor, feeding difficulty, respiratory distress); such symptoms have varied in severity and have been self-limiting in some cases and required intensive care in others.

Lactation

Palimax ER 3 mg is excreted in human breast milk. A decision on breastfeeding during treatment should weigh the benefits of breastfeeding against the mother's clinical need for Palimax ER 3 mg and any potential effects on the breastfed infant, in consultation with a physician; the infant should be monitored for sedation, abnormal muscle tone, or feeding problems if breastfeeding is continued.

Boxed Warning

Elderly patients with dementia-related psychosis treated with antipsychotic drugs, including Palimax ER 3 mg, are at an increased risk of death compared with placebo, most commonly from cardiovascular or infectious causes. Palimax ER 3 mg is not approved for the treatment of dementia-related psychosis.

Other Precautions

• Cerebrovascular adverse events: Increased risk of stroke and transient ischemic attack in elderly patients with dementia-related psychosis.
• Neuroleptic malignant syndrome (NMS): A rare but potentially fatal reaction with hyperthermia, muscle rigidity, altered mental status, and autonomic instability; discontinue Palimax ER 3 mg immediately if suspected.
• QT prolongation: Dose-dependent; avoid use with other QT-prolonging drugs and in patients with known cardiac conduction abnormalities, uncorrected electrolyte disturbances, or congenital long QT syndrome.
• Tardive dyskinesia: Risk of potentially irreversible, involuntary movements increases with duration of therapy and cumulative dose; use the lowest effective dose for the shortest duration consistent with treatment goals.
• Metabolic changes: Hyperglycemia, new-onset or worsening diabetes, dyslipidemia, and weight gain have been reported; monitor blood glucose, lipids, and body weight periodically.
• Hyperprolactinemia: May cause elevated prolactin levels with related effects (see Side Effects); use caution in patients with prolactin-dependent tumors.
• Orthostatic hypotension and syncope: Use with caution in patients with cardiovascular disease, cerebrovascular disease, or conditions predisposing to hypotension.
• Gastrointestinal narrowing: Because the tablet is non-deformable, caution is warranted in patients with severe pre-existing gastrointestinal narrowing (pathologic or iatrogenic).
• Esophageal dysmotility and aspiration: Use with caution in elderly patients with dementia, and in others at risk of aspiration pneumonia.
• Seizures: Use cautiously in patients with a history of seizure disorder or conditions that lower the seizure threshold.
• Patient counseling point: The extended-release tablet shell is non-deformable and may occasionally be seen intact in the stool; this is expected and does not indicate the Palimax ER 3 mg dose was not absorbed.

Overdose with Palimax ER 3 mg can produce exaggerated pharmacologic effects, including extrapyramidal symptoms, drowsiness, sedation, tachycardia, hypotension, and QT prolongation; gait disturbance has also been reported at very high doses. Overdose is a medical emergency.

If overdose is suspected, seek immediate medical attention or contact emergency services/a poison control center right away. There is no specific antidote; treatment is supportive, with attention to airway maintenance, oxygenation, cardiac (ECG) monitoring, and symptomatic management under close medical supervision. Do not attempt to manage an overdose at home.

Store at room temperature (below 30°C), away from light and moisture. Keep out of reach of children.

Renal Impairment

Palimax ER 3 mg is cleared primarily by the kidneys, so dosing must be reduced in renal impairment (see Dosage and Administration for the renal dosing table). Palimax ER 3 mg is not recommended in patients with severe renal impairment (CrCl less than 10 mL/min) who have not been evaluated by a physician, due to insufficient data.

Hepatic Impairment

No dose adjustment is required in mild-to-moderate hepatic impairment. Palimax ER 3 mg has not been systematically studied in severe hepatic impairment; use with caution.

Elderly / Dementia-Related Psychosis

Palimax ER 3 mg is not approved for elderly patients with dementia-related psychosis because of an increased risk of death (see Precautions and Warnings, Boxed Warning). Elderly patients may also be more susceptible to orthostatic hypotension and should generally start at the lower end of the renal-adjusted dosing range if renal function is reduced, which is common with age.

Pediatric Use

Safety and efficacy for schizophrenia have been established in adolescents 12–17 years of age using weight-based maximum doses (see Dosage and Administration). Safety and efficacy for schizoaffective disorder have not been established in patients under 18 years, and Palimax ER 3 mg is not established as safe and effective in children under 12 years of age for any indication.

Duration of treatment with Palimax ER 3 mg is individualized. Acute psychotic episodes typically require several weeks of treatment to assess response before further dose adjustment. Because schizophrenia and schizoaffective disorder are usually chronic conditions, maintenance therapy with Palimax ER 3 mg is often continued long-term to prevent relapse, with the need for continued treatment reassessed periodically by the prescribing physician, weighing benefits against risks such as tardive dyskinesia and metabolic effects. Palimax ER 3 mg should not be stopped abruptly without medical advice.

Palimax ER 3 mg belongs to the class of atypical (second-generation) antipsychotics, specifically the benzisoxazole derivatives, and is classified as a dopamine D2 / serotonin 5-HT2A receptor antagonist.

Palimax ER 3 mg exerts its antipsychotic effect mainly through antagonism of central dopamine D2 receptors and serotonin 5-HT2A receptors. This combined dopamine-serotonin antagonism is thought to improve positive and negative symptoms of psychosis while producing a lower burden of extrapyramidal symptoms than older, purely dopamine-antagonist antipsychotics. Palimax ER 3 mg also antagonizes alpha-1/alpha-2 adrenergic and H1 histaminergic receptors, contributing to effects such as orthostatic hypotension and sedation, but has minimal affinity for muscarinic cholinergic receptors.

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Palimax ER 3 mg is approved for the treatment of schizophrenia in adolescents aged 12 to 17 years, using an initial dose of 3 mg once daily with a maximum dose based on body weight (6 mg/day if under 51 kg; 12 mg/day if 51 kg or more). Safety and efficacy for schizoaffective disorder have not been established in patients under 18 years of age, and Palimax ER 3 mg is not established as safe and effective in children under 12 years for any indication. As with other antipsychotics, adolescents should be monitored closely for extrapyramidal symptoms, metabolic changes, and effects on growth and prolactin levels during treatment.