First-Line Antipsychotic Treatment in First Episode Psychosis

Recommended Initial Dosing

The British Journal of Psychiatry recommends starting with low doses of risperidone, 2 mg/day, and olanzapine, 7.5-10 mg/day, as first-line treatment for first-episode psychosis, due to their effectiveness and better tolerability compared to higher doses or typical antipsychotics 1, 2
The initial target dose for risperidone should be 2 mg/day, and for olanzapine, it should be 7.5-10 mg/day, with maximum doses not exceeding 4 mg/day risperidone or 20 mg/day olanzapine in first-episode patients 1, 2, 3, 4, 5

Doses should only be increased at widely spaced intervals (14-21 days after initial titration) if response is inadequate, to minimize the risk of extrapyramidal side-effects 1, 7
Titration should be done slowly and only within the limits of sedation and emergence of extrapyramidal side-effects, to ensure optimal tolerability and efficacy 1, 7

Atypical antipsychotics, such as risperidone, are preferred over typical antipsychotics due to their better tolerability, even at low doses, which reduces the risk of extrapyramidal symptoms and improves long-term adherence and outcomes 1, 2, 6

Typical antipsychotics, such as haloperidol, should not be used as first-line treatment, and if used, the maximum dose should be 4-6 mg/day in first-episode psychosis, due to the higher risk of extrapyramidal side-effects 1, 3, 6, 7

If positive psychotic symptoms persist after a trial of two first-line atypical antipsychotics (around 12 weeks), reasons for treatment failure should be reviewed, including medication adherence, substance misuse, underlying medical conditions, and family stresses and psychosocial factors 1, 2, 3, 6