Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.
Fluanxol Depot and Concentrated Depot (Fisons)
depot contains 20 mg/mL in 1 mL and 2 mL ampoules
concentrated depot contains 100 mg/mL in 1 mL ampoules
Flupenthixol is an antipsychotic drug of the thioxanthine class. Although the depot preparation has been marketed overseas for many years, in Australia it has only been available through the Special Access Scheme.
The depot formulations release the drug slowly after intramuscular injection with an onset of action of 24-72 hours. Although the effects can last for 2-4 weeks, the drug is not eliminated for up to 3 months. A steady state is probably reached within 6 months.
These products are intended for maintenance therapy of chronic schizophrenia and related psychoses. Shorter-acting anti psychotics should be used in patients with acute symptoms. When changing a patient to a depot formulation of flupenthixol, close supervision is required to establish the correct dose. A test dose is recommended.
Extra pyramidal adverse effects may appear a few days after an injection of flupenthixol. The drug can also cause other reactions in the nervous system, including seizures. As with the other anti psychotics, flupenthixol has other potential adverse effects including tardive dyskinesia and neuroleptic malignant syndrome. As sedation may occur, patients should be cautioned about operating machinery.