Universiti Putra Malaysia, Faculty of Medicine and Health Sciences, Malaysia.
Malays J Pathol. 2020 Apr;42(1):71-76.
Metformin is the first-line pharmacological therapy for type 2 diabetes mellitus (T2DM). Guidelines recommend metformin to be given at reduced dosages for those with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m and omitted in those with eGFR<30 mL/min/1.73m. Lactic acidosis is a known complication of those on metformin. This study aimed to determine the appropriateness of metformin prescription in T2DM patients with chronic kidney disease (CKD) stages 3-5 in a tertiary centre in Malaysia.
A cross-sectional design using retrospective secondary data of T2DM patients on metformin attending nephrology and diabetic clinics in the year 2017. eGFR calculated using the CKD-EPI formula identified those in CKD stage 3-5 defined using the National Kidney Foundation-Kidney Disease Outcomes Quality Initiative criteria. Metformin prescription was considered appropriate when the metformin maximum daily dosage does not exceed 1500 mg in CKD stage 3a and 1000 mg in CKD stage 3b and metformin stopped in CKD stages 4 and 5.
A total of 143 patients were included. Majority were in the elderly age group (62.9%), male (60.8%) and had concurrent hypertension (85.3%). Median HbA1c was 8.3% (67 mmol/mol) with most patients (88.8%) having HbA1c above 6.5% (48 mmol/ mol). Majority (92.3%) were categorised as stage 3 CKD. Eleven (7.7%) subjects had inappropriate metformin prescription. Seven of nine (78%) subjects in CKD stage 4 were on metformin with a maximum daily dose of 500 mg to1000 mg. Three patients had serum lactate measured.
The majority of CKD patients had appropriate metformin prescription. However, a considerable number of CKD stage 4 patients continued to be on metformin. The many benefits of metformin may be a reason why it is still continued against recommendations. Only three patients had lactate measured which, although may suggest that lactic acidosis is not a common occurrence, the potential for metformin-associated lactic acidosis especially in those at risk should be considered.
二甲双胍是治疗 2 型糖尿病（T2DM）的一线药物治疗方法。指南建议，肾小球滤过率（eGFR）估计值<60 mL/min/1.73m 者应降低剂量使用二甲双胍，而 eGFR<30 mL/min/1.73m 者则应停用二甲双胍。乳酸酸中毒是使用二甲双胍的已知并发症。本研究旨在确定马来西亚一家三级中心 T2DM 合并慢性肾脏病（CKD）3-5 期患者使用二甲双胍的合理性。
本研究采用回顾性二次数据分析，纳入了 2017 年在肾病和糖尿病诊所就诊的使用二甲双胍的 T2DM 患者。使用 CKD-EPI 公式计算 eGFR，根据美国国家肾脏基金会肾脏病预后质量倡议（National Kidney Foundation-Kidney Disease Outcomes Quality Initiative）标准确定 CKD 3-5 期。当 CKD 3a 期最大日剂量不超过 1500mg，CKD 3b 期不超过 1000mg 且 CKD 4 期和 5 期停用二甲双胍时，认为二甲双胍的处方是合理的。
共纳入 143 例患者，大多数患者年龄较大（62.9%），为男性（60.8%），合并高血压（85.3%）。中位糖化血红蛋白（HbA1c）为 8.3%（67mmol/mol），大多数患者（88.8%）HbA1c 高于 6.5%（48mmol/mol）。大多数患者（92.3%）为 CKD 3 期。11 例（7.7%）患者的二甲双胍处方不合理。9 例 CKD 4 期患者中有 7 例（78%）接受了最大剂量为 500mg 至 1000mg 的二甲双胍治疗。有 3 例患者检测了血清乳酸。
大多数 CKD 患者的二甲双胍处方合理。然而，相当数量的 CKD 4 期患者仍在使用二甲双胍。尽管许多益处可能是继续使用二甲双胍而不遵循建议的原因，但目前只有 3 例患者测量了乳酸，这表明乳酸酸中毒并不常见，但仍应考虑存在与二甲双胍相关的乳酸酸中毒的风险。
