Bromley Jonathan, Hughes Brett G M, Leong David C S, Buckley Nicholas A
Department of Clinical Pharmacology and Toxicology, The Canberra Hospital, Garran, Australia.
Ann Pharmacother. 2005 Sep;39(9):1566-9. doi: 10.1345/aph.1E634. Epub 2005 Jul 12.
To describe a case of severe accidental cyanide poisoning following a single ingestion of amygdalin with therapeutic intent.
A 68-year-old patient with cancer presented to the emergency department shortly after her first dose (3 g) of amygdalin with a reduced Glasgow Coma Score, seizures, and severe lactic acidosis requiring intubation and ventilation. The patient also ingested 4800 mg of vitamin C per day. She responded rapidly to hydroxocobalamin treatment. The adverse drug reaction was rated probable on the Naranjo probability scale.
Amygdalin and laetrile (a synthetic form of amygdalin) are commonly used as complementary or alternative medicine (CAM) for the treatment of cancer. Vitamin C is known to increase the in vitro conversion of amygdalin to cyanide and reduce body stores of cysteine, which is used to detoxify cyanide. Amygdalin has been used for decades by patients with cancer who are seeking alternative therapies, and severe reactions have not been reported with this dose. An interaction with vitamin C is a plausible explanation for this life-threatening response.
This case highlights the fact that CAMs can produce life-threatening toxicity. This case also adds a further note of caution, namely, the potential for serious interactions between CAMs, particularly where there is no tradition of concomitant use.
描述一例因治疗目的单次摄入苦杏仁苷后发生严重意外氰化物中毒的病例。
一名68岁癌症患者在首次服用3克苦杏仁苷后不久就诊于急诊科，格拉斯哥昏迷评分降低、出现癫痫发作，并有严重乳酸酸中毒，需要插管和通气。该患者每天还摄入4800毫克维生素C。她对羟钴胺治疗反应迅速。根据纳兰霍概率量表，该药物不良反应被评定为很可能。
苦杏仁苷和苦杏仁酸（苦杏仁苷的一种合成形式）通常用作治疗癌症的补充或替代药物（CAM）。已知维生素C会增加苦杏仁苷在体外向氰化物的转化，并减少用于解毒氰化物的半胱氨酸的体内储存。数十年来，寻求替代疗法的癌症患者一直在使用苦杏仁苷，尚未有关于此剂量出现严重反应的报道。与维生素C的相互作用是对这种危及生命反应的一个合理的解释。
本病例突出了补充或替代药物可产生危及生命的毒性这一事实。本病例还进一步提醒人们注意，尤其是在没有同时使用传统的情况下，补充或替代药物之间可能存在严重相互作用。
