Background

Paxlovid (nirmatrelvir/ritonavir) is a novel drug available under emergency use authorization by the Food and Drug Administration for the treatment of COVID-19 infection. Tacrolimus, a calcineurin inhibitor, is commonly used as an immunosuppressant medication in children with kidney transplants. While tacrolimus is metabolized by the cytochrome P450 system (CYP3A4), ritonavir is a potent CYP3A4 inhibitor. There is a paucity of data regarding the drug-drug interaction between nirmatrelvir/ritonavir and tacrolimus in children with kidney transplants.

Case-Diagnosis/Treatment

This is a case report of a 14-year-old female with a history of a kidney transplant, maintained on tacrolimus and prednisone, who starts nirmatrelvir/ritonavir for a COVID-19 infection. She subsequently develops supratherapeutic tacrolimus levels and an increase in serum creatinine. Her tacrolimus was held, and the nirmatrelvir/ritonavir was stopped. Over time, her kidney function returned to baseline, her tacrolimus levels returned to the therapeutic goal, and her tacrolimus was resumed.

Conclusions

Our case report highlights the strong interaction with concomitant use of tacrolimus and nirmatrelvir/ritonavir in a pediatric kidney transplant recipient and the development of supratherapeutic tacrolimus levels. Providers should therefore be cautious when prescribing nirmatrelvir/ritonavir to a pediatric patient currently on tacrolimus.

中文翻译：

---

在接受肾移植的儿童中使用尼马曲韦/利托那韦 (Paxlovid) 治疗 COVID-19 感染后，他克莫司水平升高

背景

Paxlovid（nirmatrelvir/ritonavir）是一种新型药物，已获得美国食品和药物管理局的紧急使用授权，可用于治疗 COVID-19 感染。他克莫司是一种钙调神经磷酸酶抑制剂，通常用作肾移植儿童的免疫抑制药物。他克莫司通过细胞色素 P450 系统 (CYP3A4) 代谢，而利托那韦是一种有效的 CYP3A4 抑制剂。关于肾移植患儿尼马曲韦/利托那韦和他克莫司之间的药物相互作用的数据很少。

病例诊断/治疗

这是一名 14 岁女性的病例报告，她有肾移植史，靠他克莫司和泼尼松维持治疗，开始使用尼马曲韦/利托那韦治疗 COVID-19 感染。她随后出现超治疗水平的他克莫司和血清肌酐升高。她停用了他克莫司，并停用了尼玛瑞韦/利托那韦。随着时间的推移，她的肾功能恢复到基线，她的他克莫司水平恢复到治疗目标，并恢复了她的他克莫司。

结论

我们的病例报告强调了在儿科肾移植受者中同时使用他克莫司和尼马曲韦/利托那韦的强烈相互作用以及超治疗他克莫司水平的发展。因此，在为目前服用他克莫司的儿科患者开具尼马瑞韦/利托那韦处方时，提供者应谨慎。