Oral versus injectable antipsychotic treatment in early psychosis: post hoc comparison of two studies.

BACKGROUND

Few studies have compared long-acting injectable second-generation antipsychotics with oral antipsychotics. Long-acting injectable antipsychotics-developed specifically to address the problem of adherence-might have an important role to play in treating early psychosis.

OBJECTIVE

The effects of oral antipsychotics versus risperidone long-acting injection (RLAI) were compared between 2 similar studies lasting 2 years each that were conducted at our site in South Africa.

METHODS

Results of an open-label study in which patients were treated with flexible doses of RLAI were compared with the results of a randomized controlled trial of flexible doses of oral risperidone or haloperidol. Inclusion criteria for both studies were age 16 to 45 years; confirmed diagnosis of schizophrenia, schizophreniform disorder, or schizoaffective disorder; <or=2 hospitalizations for psychosis; and lifetime exposure to <or=12 weeks of antipsychotic medication. The dose of RLAI was 25 mg every 2 weeks, which could be increased to 50 mg. Doses of oral risperidone or haloperidol began at 1 mg/d and were increased if necessary up to a maximum dose of 4 mg/d (8 mg/d in exceptional cases). Study assessments included the Positive and Negative Syndrome Scale (PANSS), the Extrapyramidal Symptom Rating Scale (ESRS), and body mass index (BMI).

RESULTS

The RLAI group included 50 patients (32 men and 18 women; mean [SD] age, 25.4 [7.4] years; BMI, 20.6 [4.6] kg/m(2)). The oral risperidone or haloperidol group included 47 patients (27 men and 20 women; mean [SD] age, 25.9 [5.8] years; BMI, 20.1 [3.4] kg/m(2)). Compared with patients treated with oral risperidone or haloperidol, RLAI-treated patients had significantly fewer all-cause discontinuations (26.0% [13/50] vs 70.2% [33/47] at 24 months; P < 0.005), greater reduction on the PANSS total score (-39.7 vs -25.7; P = 0.009), higher remission rate (64.0% [32/50] vs 40.4% [19/47]; P = 0.028), and lower relapse rate (9.3% [4/43] vs 42.1% [16/38]; P = 0.001) among the responders. Extrapyramidal symptoms were significantly lower in the RLAI group than in patients treated with oral risperidone or haloperidol, as measured by the maximum change in the mean [SD] ESRS total score (1.40 [2.60] vs 5.61 [5.21] vs 9.04 [6.21], respectively; P <or= 0.001). The increase in BMI after 6 months was significantly greater in the RLAI group than in oral haloperidol-treated patients (mean [SD], 3.9 [1.9] vs 2.2 [1.3] kg/m(2); P = 0.001) but not significantly different from oral risperidone (3.4 [2.0] kg/m(2); P = NS). Four patients in the RLAI group had adverse events that were possibly related to prolactin, compared with 1 each in the oral risperidone and haloperidol groups.

CONCLUSIONS

The findings of this post hoc analysis suggest that there were advantages in terms of efficacy, fewer extrapyramidal symptoms, and more weight gain with long-acting injectable second-generation antipsychotics as compared with oral antipsychotic treatment in early-episode psychosis.