Mode of administration

What is mode of administration?

Studies have shown that about 80% of patients relapse to psychosis within 5 years of initial treatment. This is often due to lack of adherence to antipsychotic medications. Long-acting injectable antipsychotics are a treatment option for patients who are not adhering to treatment or who do not remember to take their oral preparations.

What is the evidence for mode of administration?

Moderate to high quality evidence shows long-acting injectable second-generation antipsychotics are more effective than placebo injections for symptom improvement. There were small effects of fewer relapses, longer time to relapse, and fewer hospital days with long-acting injectable second-generation antipsychotics compared to oral second-generation antipsychotics. There was also a large effect of lower hospitalisation rates with long-acting injectables.

High quality evidence finds no differences in rates of at least one adverse event between long-acting injectable and oral antipsychotics, although there were more extrapyramidal symptoms and low-density lipoprotein cholesterol change with injectables. Moderate to high quality evidence also finds more anxiety, and moderate to low quality evidence finds more akinesia with long-acting injectable antipsychotics.

For individual antipsychotics, moderate to low quality evidence finds fewer relapses with long-acting injectable fluphenazine compared to oral fluphenazine. Moderate to high quality evidence found no differences in response or relapse rates between injectable and oral risperidone, olanzapine, or aripiprazole. Moderate quality evidence finds no differences in response or relapse rates between injectable and oral haloperidol. There were no differences between injectable or oralĀ  formulations in adverse effects, apart from a small effect of less hyperprolactinemia with long-acting injectable risperidone and more dropouts due to inefficacy with long-acting injectable olanzapine.

October 2019

Last updated at: 4:15 am, 15th October 2019
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