Effectiveness of long-acting injectable antipsychotics: a clinical perspective


The personal and societal costs of schizophrenia spectrum disorders are immense. Affected individuals may experience positive, negative and mood symptoms; medical and substance use comorbidities; and cognitive impairment that significantly impair social and occupational functioning. Globally, schizophrenia is a leading cause of years lost to disability, with a particularly large burden among adolescents and young adults.1

Treatment of schizophrenia spectrum disorders aims at improved functioning and recovery across the lifespan, but symptom reduction and relapse prevention are important interim goals. Although antipsychotic medications reduce psychotic symptoms and greatly decrease the risk of relapse, their effectiveness in real-world practice is decreased by non-adherence.2 A meta-analysis of studies that used trained personnel to measure antipsychotic medication adherence found that not ‘regularly taking medications as prescribed’ is prevalent in an average of 41% of participants across 10 studies.3 Despite this high prevalence, providers are often unaware of this issue and generally overestimate medication adherence in their patients.4

Long-acting injectable (LAI) formulations of antipsychotic medications were developed to improve adherence. The first LAIs, fluphenazine enanthate and decanoate, were introduced in 1966 in the context of large-scale deinstitutionalisation of patients with serious mental illnesses and the consequent need for effective community-based treatment. Numerous LAI antipsychotics have been developed and marketed in the meantime. Table 1 lists the LAI antipsychotic medications currently available in the USA and the UK.5 ,6