HALDOL

What it is

HALDOL DECANOATE is haloperidol decanoate, supplied as a solution for intramuscular oily injection containing either 50 mg haloperidol per 1 mL or 150 mg haloperidol per 3 mL. The injection is a slightly amber, slightly viscous solution. HALDOL DECANOATE is a long-acting form of haloperidol; when administered as an intramuscular depot injection in sesame oil, esterases in the blood and tissues hydrolyse haloperidol decanoate to provide slow release of the active neuroleptic haloperidol into the systemic circulation.

Approved indications

— Maintenance therapy of psychoses in adults, particularly for patients requiring prolonged parenteral neuroleptic therapy.

Dosing overview

Patients must be previously stabilised on oral haloperidol before converting to HALDOL DECANOATE, and treatment initiation and dose titration must be carried out under close clinical supervision. The recommended interval between doses is usually 4 weeks. HALDOL DECANOATE should be administered by deep intramuscular injection into the gluteal region. HALDOL DECANOATE must not be administered intravenously.

Key safety warnings

Rare cases of sudden death have been reported in psychiatric patients receiving antipsychotic drugs, including HALDOL DECANOATE. Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death, with analyses of seventeen placebo-controlled trials revealing a risk of death in drug-treated patients of between 1.6 to 1.7 times the risk in placebo-treated patients. Very rare reports of QT interval prolongation and ventricular arrhythmias have been reported in patients receiving haloperidol, occurring more frequently with high doses and in predisposed patients. A baseline electrocardiogram is recommended before treatment, and during therapy, the need for electrocardiogram monitoring for QT interval prolongation and ventricular arrhythmias must be assessed in all patients; the dose should be reduced if QT is prolonged, but haloperidol must be discontinued if QT exceeds 500 milliseconds. Neuroleptic malignant syndrome has been reported; cardinal features include hyperthermia, muscle rigidity, altered mental status, and autonomic instability, with hyperthermia often an early sign. This syndrome is potentially fatal, requires intensive symptomatic treatment, and immediate discontinuation of neuroleptic treatment. Extrapyramidal reactions such as Parkinson-like symptoms, akathisia, or dystonic reactions occur frequently with antipsychotics including haloperidol and have been observed with HALDOL DECANOATE; in most patients these symptoms are usually mild to moderately severe and usually reversible, and are more commonly observed during the first few days of treatment. Tardive dyskinesia, a syndrome of potentially irreversible involuntary dyskinetic movements, is known to occur in patients treated with neuroleptics; it may appear during long-term therapy or after drug therapy has been discontinued, the symptoms are persistent, and although the syndrome may remit partially or completely if medication is withdrawn, it is irreversible in some patients, with the highest prevalence among elderly patients, especially elderly women. Clinically significant weight gain has been reported in patients taking HALDOL DECANOATE, and patients taking antipsychotic medications should undergo regular monitoring of weight and testing of other parameters such as blood glucose and haemoglobin A1C.

Contraindications

HALDOL DECANOATE is contraindicated in individuals who are hypersensitive to haloperidol or to any excipients, in comatose states from any cause, in the presence of central nervous system depression due to alcohol or other depressant drugs, in patients with significant depressive states, in patients with previous spastic diseases, in patients with Parkinson's syndrome except in the case of dyskinesias due to levodopa treatment, in senile patients with pre-existing Parkinson-like symptoms, in patients with dementia with Lewy bodies, and in patients with progressive supranuclear palsy.

PBS listing

HALDOL DECANOATE 150 mg in 3 mL ampoule is listed on the PBS with unrestricted access at an ex-manufacturer price of A$30.68, and the 50 mg in 1 mL ampoule is listed on the PBS with unrestricted access at an ex-manufacturer price of A$15.30.

Regulatory history

HALDOL DECANOATE haloperidol 50 mg/1 mL was first listed on the Australian Register of Therapeutic Goods on 28 August 1991, and the 150 mg/3 mL formulation was first listed on 8 November 1993.