Long-acting injectable antipsychotics: evidence of effectiveness and use

To review the evidence for the role of long-acting injectable (LAI) antipsychotics (APs), especially the second-generation AP (SGA) LAIs, in the treatment of schizophrenia and to discuss the use rates of LAIs in Canada.

A search of online medical databases was conducted of the published literature (1995-2012) of the effects of LAIs on the domains of remission, adherence, relapse, and hospitalization. Results obtained from randomized controlled trials (RCTs), systematic reviews, meta-analyses, and large-scale observational studies were included. Expert consensus data were also solicited on LAI use within a Canadian context.

While the efficacy of LAIs, compared with placebo, is well established, the evidence from RCTs is equivocal for any specific advantage for SGA LAIs, compared with oral medications, probably owing to challenges in conducting such RCTs. Evidence from methodologically less rigorous studies and from clinical practice suggests some advantages in achieving and maintaining remission, risk of relapse, and hospitalization. The rate of LAI (first-generation AP and SGA) use from published outpatient studies is low at 6.3% in Canada, compared with 15% to 80% worldwide. However, there is a relatively high rate of use in specific early psychosis programs and in conjunction with community treatment orders in Canada.

LAIs are at least as effective as oral APs in the treatment of psychotic disorders. The former may have specific advantages for patients who demonstrate covert nonadherence. The underuse of LAIs in Canada needs to be better understood and addressed.