GLP-1 receptor agonists significantly mitigate metabolic side effects of clozapine and olanzapine therapy in psychiatric patients.

Patients with schizophrenia often require potent antipsychotics like clozapine and olanzapine, which are highly effective but carry severe metabolic side effects. These include significant weight gain, dyslipidemia, and insulin resistance, substantially increasing cardiovascular risk and reducing treatment adherence. Current standard-of-care often falls short in managing these complications effectively. Glucagon-like peptide-1 (GLP-1) receptor agonists, known for their roles in glucose homeostasis and weight management, offer a promising therapeutic avenue to counteract these antipsychotic-induced metabolic disturbances by targeting the GLP-1R pathway.

This literature review systematically investigated the potential of GLP-1 receptor agonists in mitigating metabolic side effects from clozapine or olanzapine. Researchers searched PubMed and Google Scholar using terms like "clozapine OR olanzapine AND GLP-1 agonist" and "schizophrenia AND GLP-1 agonist." From an initial 172 articles, the review focused on clinical trials and case reports, ultimately including two clinical trial studies, one case report, and one retrospective study. The primary endpoint was the impact of GLP-1 agonists on metabolic parameters in patients receiving these antipsychotics.

The review highlighted compelling evidence for GLP-1 agonists' metabolic benefits. In a case report, a schizophrenic patient on clozapine treated with liraglutide saw HbA1c drop from 10% to 6.5% over 14 months, alongside a 7.7 kg (8.7% body weight) reduction over two years, and decreased insulin requirements. A retrospective study of 16 obese patients with schizophrenia (14 on clozapine) treated with liraglutide observed significant reductions in body weight, waist circumference, BMI, and plasma glucose levels over 16 weeks (P < 0.001).