Paliperidone

Intramuscular
Schizophrenia

Oral
Schizophrenia

Oral:

CrCl (mL/min)	Dosage
≥10 to <50	Initially, 1.5 mg once daily, may be increased to 3 mg once daily thereafter.
≥50 to <80	Initially, 3 mg once daily, may be increased to 6 mg once daily, according to response and tolerance.

Intramuscular:

CrCl (mL/min)	Dosage
≥50 to <80	Initially, 100 mg on day 1, then 75 mg after a wk. Mthly maintenance dose: 50 mg. Usual range: 25-100 mg.

May be taken with or without food. Take consistently either always w/ or always w/o food. Swallow whole, do not divide/chew/crush.

Hypersensitivity to paliperidone or risperidone.

Patient w/ known CV disease or family history of QT prolongation, history of seizures or other conditions that potentially lower the seizure threshold, predisposition to GI obstruction, possible prolactin-dependent tumours, Parkinson's disease. Cataract surgery. Elderly w/ dementia-related psychosis and risk factors for stroke. Renal impairment. Pregnancy and lactation.

Headache, dizziness, somnolence, sedation, agitation, fatigue, constipation, dyspepsia, dry mouth, nausea, vomiting, wt gain, akathisia, dystonia, hypertonia, tremor, tachycardia (including nasopharyngitis), blurred vision, orthostatic hypotension, arthralgia, back pain, pain in extremities, priapism, agranulocytosis, leucopenia, neutropenia. Rarely, tardive dyskinesia, small intestinal obstruction, hyperprolactinaemia resulting in gynaecomastia, menstrual disturbances, amenorrhoea, galactorrhoea.
Potentially Fatal: Neuroleptic malignant syndrome, CVA, transient ischaemic attacks.

IM/Parenteral/PO: C

This drug may cause somnolence and impairment of judgment, thinking or motor skills, if affected, avoid driving, operating machinery or performing hazardous tasks.

Monitor mental status changes, vital signs, wt, BP, electrolyte, renal and hepatic function. Closely monitor for worsening glucose control in patients w/ pre-existing DM.

Symptoms: Drowsiness, sedation, tachycardia, hypotension, QT prolongation, extrapyramidal symptoms, torsades de pointes, ventricular fibrillation. Management: Symptomatic and supportive treatment. Establish and maintain a clear airway and ensure adequate oxygenation and ventilation. Treat hypotension and circulatory collapse w/ IV fluid and/or sympathomimetic agents. Consider gastric lavage and admin of activated charcoal w/ a laxative. In case of severe extrapyramidal symptoms, admin anticholinergic agents.

Increased risk of QT prolongation w/ class IA (e.g. quinidine, disopyramide) and class III (e.g. amiodarone, sotalol) antiarrhythmics. Additive effects w/ drugs that cause orthostatic hypotension (e.g. other antipsychotics, tricyclics). May antagonise actions of levodopa and other dopaminergics. Additive effect w/ drugs known to lower seizure threshold (e.g. phenothiazines or butyrophenones, clozapine, tricyclics or SSRIs, tramadol, mefloquine). May reduce plasma levels w/ carbamazepine. Enhanced central effects w/ other CNS depressants. May increase plasma levels w/ valproate. May affect the absorption w/ metoclopramide.

Enhanced central effects of alcohol.

Description: Paliperidone is a benzisoxazole atypical antipsychotic which is a main active metabolite of risperidone. It is an antagonist at dopamine D₂, serotonin (5-HT_2A), adrenergic (α₁ and α₂), and histamine (H₁) receptors.
Pharmacokinetics:
Absorption: Bioavailability: 28%. Time to peak plasma concentration: Approx 24 hr (oral); approx 13 days (IM).
Distribution: Plasma protein binding: 74% (mainly to α₁-acid glycoprotein and albumin).
Metabolism: Hepatic by CYP2D6 and CYP3A4 isoenzymes; minor metabolism via dealkylation, hydroxylation, dehydrogenation and benzisoxazole scission.
Excretion: Via urine (80%) and faeces (11%). Elimination half-life: Approx 23 hr (oral); 25-49 days (IM).

Source: National Center for Biotechnology Information. PubChem Database. Paliperidone, CID=115237, https://pubchem.ncbi.nlm.nih.gov/compound/Paliperidone (accessed on Jan. 22, 2020)

Store below 30°C. Protect from moisture.

Antipsychotics

Anon. Paliperidone. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 24/11/2014.

Buckingham R (ed). Paliperidone. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 24/11/2014.

Invega Extended-release Tablets. U.S. FDA. https://www.fda.gov/. Accessed 24/11/2014.

Joint Formulary Committee. Paliperidone. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 24/11/2014.

McEvoy GK, Snow EK, Miller J et al (eds). Paliperidone. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 24/11/2014.