Department of Maternal and Pediatric Sciences, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Commenda 9, 20122 Milan, Italy.
J Clin Virol. 2010 May;48(1):62-5. doi: 10.1016/j.jcv.2010.02.019. Epub 2010 Mar 23.
Oseltamivir is considered the drug of choice for patients with pandemic influenza for whom drug treatment is recommended because adamantanes seem to be ineffective against pandemic A/H1N1 influenza virus and zanamivir is contraindicated in people with underlying respiratory conditions and difficult to administer in younger children.
To increase knowledge on oseltamivir resistance emergence in pandemic A/H1N1 influenza.
Description of the case of an 8-year-old boy with cystic fibrosis and Pseudomonas aeruginosa infection in whom an oseltamivir-resistant pandemic A/H1N1 influenza virus was demonstrated.
On the basis of clinical and virological failure (nasopharyngeal secretions remained positive for pandemic A/H1N1 influenza virus and appearance of 275Y mutation in 100% virus population) on fifth day of treatment, oseltamivir was replaced by zanamivir inhalation (5mg to be inhaled twice a day). This change was associated with a rapid improvement in the patient's general condition, respiratory findings and laboratory data (including disappearance of pandemic A/H1N1 influenza virus) in the absence of any adverse event.
The emergence of oseltamivir-resistant strains is related to the administration of the drug, supporting the restriction of oseltamivir use to carefully defined high-risk groups. Infection due to pandemic virus with the H275Y mutation can be associated with a severe clinical course, supporting the systematic monitoring of antiviral susceptibility in pandemic influenza-positive high-risk patients whose influenza is not resolved by oseltamivir treatment. Zanamivir inhalation can be successfully used in patients with cystic fibrosis without causing adverse respiratory events, highlighting that the risks and benefits of this drug must be considered on a patient by patient basis.
奥司他韦被认为是治疗流感大流行患者的首选药物，因为金刚烷胺似乎对大流行的 A/H1N1 流感病毒无效，而扎那米韦在有基础呼吸道疾病的人群中被禁用，并且在年幼的儿童中难以给药。
增加对大流行的 A/H1N1 流感中奥司他韦耐药性出现的认识。
描述了一例患有囊性纤维化和铜绿假单胞菌感染的 8 岁男孩的病例，该男孩被证实患有奥司他韦耐药性大流行的 A/H1N1 流感病毒。
在治疗的第五天，由于临床和病毒学失败（鼻咽分泌物仍然呈大流行的 A/H1N1 流感病毒阳性，并且 100%的病毒群体中出现 275Y 突变），奥司他韦被替换为扎那米韦吸入剂（每天吸入两次，每次 5mg）。这种变化与患者一般状况、呼吸发现和实验室数据（包括大流行的 A/H1N1 流感病毒的消失）的快速改善相关，且没有任何不良事件发生。
奥司他韦耐药株的出现与药物的使用有关，支持将奥司他韦的使用限制在仔细定义的高危人群中。具有 H275Y 突变的大流行病毒感染可能与严重的临床病程相关，支持对大流行流感阳性的高危患者进行系统监测抗病毒敏感性，这些患者的流感未通过奥司他韦治疗得到解决。扎那米韦吸入剂可成功用于囊性纤维化患者，而不会引起不良的呼吸事件，突出表明必须根据患者的情况考虑该药物的风险和益处。
