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.
Clopixol-Acuphase (Lundbeck Australia)
50 mg/mL intramuscular injection in 1mL and 2 mL ampoules
Thioxanthines are antipsychotic drugs with a similar structure to the phenothiazines. The more potent phenothiazines, e.g. fluphenazine, have a piperazine group added to the molecule; zuclopenthixol is a thioxanthine with a piperazine substitution. Thioxanthines have been used in schizophrenia and the manic phase of manic depressive illness as they block D1 and D2 dopamine receptors.
This formulation of zuclopenthixol is indicated for the treatment of acute psychoses, mania or exacerbations of chronic psychoses. An intramuscular injection takes 36 hours to produce a maximum serum concentration. The concentration falls by approximately 60% over 3 days so the injection can be repeated after 2 or 3 days if needed. The duration of treatment should not exceed two weeks and the total course should not exceed 4 injections or 400 mg.
Zuclopenthixol is probably as effective as similar antipsychotics and the adverse reaction profile is also similar. The most common adverse effects are extra pyramidal symptoms and drowsiness.