FLUPENTHIXOL INJECTION

Indications

• Schizophrenia
• Acute psychosis
• Chronic psychotic disorders
• Severe anxiety disorders

Dosage

Adults: The usual starting dose for flupenthixol in adults is 0.5 to 2 mg daily, which may be adjusted based on clinical response and tolerability. For severe cases, doses may be increased gradually to a maximum of 6 mg daily. The injectable form may be used

Mechanism of action

Flupenthixol exerts its therapeutic effects mainly through antagonism of dopamine D2 receptors in the central nervous system. This blockade of dopamine transmission is believed to alleviate psychotic symptoms. Flupenthixol also has some affinity for serotonin receptors, which may play a role in its efficacy in managing anxiety and mood disturbances. Overall, the drug works to rebalance neurotransmitter activity in the brain.

Pharmacodynamics

Flupenthixol demonstrates a dose-dependent effect on symptoms of schizophrenia, including hallucinations, delusions, and disorganized thinking. Its efficacy is attributed to its ability to reduce dopaminergic overactivity in the mesolimbic pathway, while also potentially enhancing dopaminergic activity in the mesocortical pathway, which may help improve negative symptoms associated with schizophrenia. The anxiolytic effects are likely mediated through interaction with serotonin pathways, contributing to its overall therapeutic profile.

Pharmacokinetics

Flupenthixol is well absorbed following oral administration, with peak plasma concentrations occurring within a few hours. The drug is extensively metabolized in the liver, with a half-life of approximately 24 hours, allowing for once or twice daily dosing. Flupenthixol is primarily excreted as metabolites in urine. The pharmacokinetics can be influenced by factors such as age, liver function, and concurrent medications, necessitating careful monitoring and possible dose adjustments in specific populations.

Contra-indications

• Hypersensitivity to flupenthixol or any of the excipients
• Severe central nervous system depression
• Comatose states
• Parkinson's disease
• Phaeochromocytoma

Adverse effects

• Drowsiness
• Extrapyramidal symptoms
• Dry mouth
• Blurred vision
• Constipation
• Weight gain
• Hyperprolactinaemia
• Cardiovascular effects including tachycardia and hypotension

Interactions

• Increased sedation with CNS depressants such as alcohol, barbiturates, and benzodiazepines
• Antihypertensives may have additive effects leading to hypotension
• Anticholinergic drugs may exacerbate anticholinergic side effects
• Concomitant use with other antipsychotics may increase the risk of adverse effects

Precautions

• Use with caution in patients with a history of seizures
• Patients with liver impairment may require dose adjustments
• Monitor for symptoms of tardive dyskinesia
• Caution in elderly patients or those with cardiovascular disease

Pregnancy

Flupenthixol should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Consult appropriate guidelines.

Breast-feeding

Flupenthixol is excreted in breast milk. Caution is recommended, and breastfeeding should be avoided if the mother is treated with flupenthixol.

Storage

Store below 25°C, protect from light. Keep out of reach of children.

Formulations

• Tablets: 0.5 mg, 1 mg, 2 mg
• Injection: 20 mg/mL in ampoules