一位患有第 2 型糖尿病的病人正服用 metformin。護理師應最密切監測哪項實驗室數值以預防併發症？
A client with type 2 diabetes mellitus is prescribed metformin. Which laboratory value should the nurse monitor most closely to prevent complications?
- AWhite blood cell count白血球計數
- BGlycosylated hemoglobin (HbA1c)糖化血色素 (HbA1c)
- CSerum potassium血清鉀
- DSerum creatinine✓ 正解血清肌酸酐
Metformin（雙胍類）最嚴重的副作用是乳酸中毒（Lactic acidosis），雖然發生率低但致死率高。由於 Metformin 主要經由腎臟排泄，若病人存在腎功能不全，藥物會在體內蓄積，顯著增加乳酸中毒的風險。因此，監測血清肌酸酐（Serum Creatinine）或腎絲球過濾率（GFR）是服用此藥病人的首要安全措施。HbA1c（B）是用於評估血糖控制的長期指標，而非安全性監測指標。血鉀（C）與白血球（A）與 Metformin 的直接毒性或常見副作用關聯性較低。臨床思路上，安全監測（預防毒性）優於療效監測（血糖控制）。
The most serious adverse effect of metformin (a biguanide) is lactic acidosis; although uncommon, it carries a high mortality rate. Because metformin is primarily excreted by the kidneys, impaired renal function leads to drug accumulation and substantially increases the risk of lactic acidosis. Monitoring serum creatinine (or glomerular filtration rate, GFR) is therefore the primary safety measure for clients on this drug. HbA1c (B) is a long-term indicator of glycemic control rather than a safety-monitoring parameter. Serum potassium (C) and white blood cell count (A) have weak clinical relevance to metformin's direct toxicity or common adverse effects. Clinically, safety monitoring (preventing toxicity) takes precedence over efficacy monitoring (glycemic control).
美國 FDA 規定若 eGFR 低於 30 應停用 Metformin，護理師需主動核對數值。台灣臨床上亦強調腎功能，但有時會因病人同時看多科而忽略藥物整合，護理師在藥物諮詢時需特別注意。