醫療藥品對尿液中嗎啡及甲基安非他命免疫分析之影響
Interference of The Therapeutic Dsugs on Immunoassay of
中文摘要 尿液檢驗結果往往受其他物質的干擾而呈現偽陽性或偽陰性,免疫分析方法為一 般初步篩檢採用之方法,其所受之影響最大。如尿液檢體攙加清潔劑等強離子性 或強鹼、強酸性化學物質，或受驗者飲食狀況、共同服用藥物等因素都有可能造 成免疫分析方法之偽陽性或偽陰性結果。本研究選用十一種國人常用之抗組織 胺、非類固醇抗發炎藥、維他命等藥品，測試對 DRI 及 TDx 之嗎啡及甲基安非 他命免疫檢驗之干擾，並對 DRI 發生干擾之反應機轉進行研究。 實驗結果如下：所攙加的十一種藥品 tolmetin 因於 UV 340nm 有極高吸光度引起 DRI 甲基安非他命偽陰性反應；diphenhydramine、pheniramine 、trimethobenzamide 與抗體有結合力造成 DRI 嗎啡檢測值微增，trimethobenzamide 也因此而引起甲 基安非他命檢測值劇增。Chlorpromazine 因為以上兩種因素使得 DRI 嗎啡檢驗 呈現偽陽性，因為 UV 吸收使得 DRI 甲基安非他命檢測值微增。同樣十一種藥 品僅有 chlorpromazine、trimethobenzamide 對 TDx 的嗎啡及甲基安非他命檢測造 成偽陽性干擾，統計以上結果 TDx 試劑的偽陽性率略低於 DRI 試劑。同時在本 研究我們發現尿液檢體中攙加高濃度 (≧2%) 還原電位(pH 7)大於 NADH 之化 合物如 ascorbic acid 等，能抑制 NAD+轉變成 NADH 而引起 DRI 試劑檢驗呈現 偽陰性。除了含有 chlropromazine 的尿液，所有發生干擾現象之尿液檢體可以氣 相層析質譜分析 (GC/MS) 作確認試驗。英文摘要
It is known that urine tests may be interfered with other substances to cause false results. Urine immunoassay, the most common screening method for drugs of abuse, is especially sus-ceptible to adulterant-induced false results. Eleven adulterating agents from three types of therapeutic drugs: antihistamines,nonsteroidal
anti-inflammatory drugs (NSAIDs), and vitamins, were evaluated for potential
interference with DRI and TDx opiates and amphetamines immunoassay. Mechanisms of adulterant interference with DRI were also discussed. In our study showed that high molar UV absorbance at 340nm of tolmetin interfered negatively with DRI methamphetamine immunoassay. Being structure-similarity with the antigen of reagents, diphenhydramine, pheniramine and trimethobenzamide resulted in slight increasing measurements of morphine by DRI opiate immunoassay. For the same reason, trimethobenzamide caused dramatically increasing in methamphetamine assay. Chlorpromazine interfered positively with morphine through both cross reaction and UV absorptivity, with methamphetamine through UV absorptivity. Among the
eleven tested adulterants, only chlorpromazine and trimethobenzamide positively interfered both immunoassay of TDx. Concurrently we found that adulterated high concentration (≧2%) of redox agents, which have more powerful reducing strength than nicotinamide adenine dinucleotide (NAD+), like ascorbic acid may inhibit the conversion of NAD+ to NADH, therefore interfer DRI immunoassay negatively. All puzzling specimens but the ones adulterated with chlorpromazine, could be confirmed by gas chromatography/mass spectrometry (GC/MS).
