Farache Trajano Luiza, Hayes Joseph F, Launders Naomi, Davies Neil M, Osborn David P J, Richards-Belle Alvin
Division of Psychiatry, University College London, London, UK.
North London NHS Foundation Trust, London, UK.
BMJ Ment Health. 2025 Apr 2;28(1):e301505. doi: 10.1136/bmjment-2024-301505.
Metformin is a pharmacological candidate to mitigate second-generation antipsychotic (SGA)-induced weight gain in patients diagnosed with severe mental illnesses (SMI).
To determine the incidence, prevalence and demographic patterns of metformin co-prescription among patients diagnosed with SMI initiating SGAs. To estimate the impact of metformin co-prescription on weight over 2 years post-SGA initiation.
A cohort study of patients diagnosed with SMI initiating aripiprazole, olanzapine, quetiapine or risperidone in 2005-2019 using primary care data from Clinical Practice Research Datalink. We estimated cumulative incidence and period prevalences of co-prescription and explored prescribing differences by demographic and clinical factors. We compared weight change among patients prescribed an SGA-only versus an SGA plus metformin, accounting for confounders using linear regression.
Among 26 537 patients initiating SGAs, 4652 were ever prescribed metformin and 21 885 were not. The two-year incidence of first metformin prescription was 3.3%. The SGA plus metformin group were more ethnically diverse, had greater social deprivation, more comorbidities and higher baseline weight (mean 90.4 vs 76.8 kg). By 2 years post-SGA initiation, mean weight in the SGA-only group had changed by +4.16% (95% CI -1.26 to +9.58) compared with -0.65% (95% CI -4.26 to +2.96) in the SGA plus metformin group. After confounder adjustment, the 2-year mean difference in weight with metformin co-prescription was -1.48 kg (95% CI -4.03 to 1.07) among females and -1.84 kg (95% CI -4.67 to 0.98) among males.
Metformin is infrequently co-prescribed, despite apparent efficacy and guidelines.
Primary and secondary care collaboration should be strengthened and barriers to co-prescribing addressed.
二甲双胍是一种有可能减轻被诊断患有严重精神疾病（SMI）的患者因使用第二代抗精神病药物（SGA）导致体重增加的药物。
确定开始使用SGA的SMI患者中二甲双胍联合处方的发生率、患病率及人口统计学模式。评估二甲双胍联合处方对SGA开始使用后2年体重的影响。
一项队列研究，使用来自临床实践研究数据链的初级保健数据，研究2005年至2019年开始使用阿立哌唑、奥氮平、喹硫平或利培酮的SMI患者。我们估计了联合处方的累积发生率和期间患病率，并探讨了人口统计学和临床因素对处方的影响。我们比较了仅使用SGA与使用SGA加二甲双胍的患者的体重变化，使用线性回归分析混杂因素。
在26537例开始使用SGA的患者中，4652例曾使用过二甲双胍，21885例未使用过。首次使用二甲双胍处方的两年发生率为3.3%。SGA加二甲双胍组的种族更加多样化，社会剥夺程度更高，合并症更多，基线体重更高（平均90.4对76.8千克）。到SGA开始使用后2年，仅使用SGA组的平均体重变化了+4.16%（95%CI -1.26至+9.58），而SGA加二甲双胍组为-0.65%（95%CI -4.26至+2.96）。在调整混杂因素后，联合使用二甲双胍的女性2年体重平均差异为-1.48千克（95%CI -4.03至1.07），男性为-1.84千克（95%CI -4.67至0.98）。
尽管二甲双胍有明显疗效且有指南推荐，但联合处方的情况并不常见。
应加强初级保健和二级保健之间的合作，并解决联合处方的障碍。
