Menakuru Sasmith R, Dhillon Vijaypal S, Atta Mona, Mann Keeret, Salih Ahmed
Department of Internal Medicine, Indiana University School of Medicine-Muncie, Muncie, IN 47306, USA.
Hematol Rep. 2023 May 24;15(2):325-330. doi: 10.3390/hematolrep15020034.
Methemoglobinemia is an acute medical emergency that requires prompt correction. Physicians should have a high degree of suspicion of methemoglobinemia in cases that present with hypoxemia that does not resolve with supplemental oxygenation, and they should confirm this suspicion with a positive methemoglobin concentration on arterial blood gas. There are multiple medications that can induce methemoglobinemia, such as local anesthetics, antimalarials, and dapsone. Phenazopyridine is an azo dye used over-the-counter as a urinary analgesic for women with urinary tract infections, and it has also been implicated in causing methemoglobinemia. The preferred treatment of methemoglobinemia is methylene blue, but its use is contraindicated for patients with glucose-6-phosphatase deficiency or those who take serotonergic drugs. Alternative treatments include high-dose ascorbic acid, exchange transfusion therapy, and hyperbaric oxygenation. The authors report a case of a 39-year-old female who took phenazopyridine for 2 weeks to treat dysuria from a urinary tract infection and subsequently developed methemoglobinemia. The patient had contraindications for the use of methylene blue and was therefore treated with high-dose ascorbic acid. The authors hope that this interesting case promotes further research into the utilization of high-dose ascorbic acid for managing methemoglobinemia in patients who are unable to receive methylene blue.
高铁血红蛋白血症是一种需要迅速纠正的急性医疗急症。对于出现低氧血症且补充氧气后仍无法缓解的病例，医生应高度怀疑高铁血红蛋白血症，并应通过动脉血气分析中高铁血红蛋白浓度呈阳性来确认这种怀疑。有多种药物可诱发高铁血红蛋白血症，如局部麻醉剂、抗疟药和氨苯砜。非那吡啶是一种偶氮染料，作为非处方药物用于治疗患有尿路感染的女性的尿痛，它也被认为与高铁血红蛋白血症的发生有关。高铁血红蛋白血症的首选治疗方法是亚甲蓝，但对于葡萄糖 -6-磷酸酶缺乏症患者或服用血清素能药物的患者，使用亚甲蓝是禁忌的。替代治疗方法包括大剂量维生素C、换血疗法和高压氧疗。作者报告了一例39岁女性病例，该女性服用非那吡啶2周以治疗尿路感染引起的排尿困难，随后发展为高铁血红蛋白血症。该患者有使用亚甲蓝的禁忌证，因此接受了大剂量维生素C治疗。作者希望这个有趣的病例能促进对大剂量维生素C用于治疗无法接受亚甲蓝治疗的患者的高铁血红蛋白血症的进一步研究。
