Tang Jennifer H, Davis Nicole L, Corbett Amanda H, Chinula Lameck, Cottrell Mackenzie L, Zia Yasaman, Tegha Gerald, Stanczyk Frank Z, Hurst Stacey, Hosseinipour Mina C, Haddad Lisa B, Kourtis Athena P
University of North Carolina at Chapel Hill, 111 Mason Farm Road, CB #7577; Chapel Hill, NC, 27599-7577, USA.
UNC Project Malawi, 100 Mzimba Drive, Private Bag A104, Lilongwe, Malawi.
Contracept X. 2020 May 29;2:100027. doi: 10.1016/j.conx.2020.100027. eCollection 2020.
Our primary objective was to compare geometric mean levonorgestrel concentrations between levonorgestrel implant users who were or were not taking the antiretroviral efavirenz, for up to 30 months after implant initiation. Our secondary objective was to evaluate the pregnancy rate among levonorgestrel implant users on efavirenz.
We performed a subanalysis of 42 Malawian women randomized to initiate the levonorgestrel implant as part of a parent randomized clinical trial. Our subset included 30 HIV-infected women taking efavirenz and 12 HIV-uninfected women not taking efavirenz. They underwent urine pregnancy testing every 3 months and serum levonorgestrel testing at day 3 and months 1, 3, 6, 12, 18, 24, 27 and 30 after implant initiation. Geometric mean levonorgestrel concentrations were calculated for efavirenz users and non-efavirenz users at each time point.
The geometric mean levonorgestrel concentrations were lower for efavirenz users than non-efavirenz users at every time point; the geometric mean ratio for efavirenz users:non-efavirenz users ranged from 0.60 [90% confidence interval (CI) 0.46-0.79] at 1 month to 0.27 (90% CI 0.12-0.61) at 30 months after implant insertion. No pregnancies occurred over 60 woman-years of concomitant levonorgestrel implant and efavirenz use, although 11 women had levonorgestrel concentrations < 180 pg/mL (the previously suggested minimum threshold concentration for efficacy).
Efavirenz users had lower levonorgestrel concentrations than non-efavirenz users, and one third of our concomitant efavirenz and levonorgestrel implant users had concentrations < 180 pg/mL. Continued evaluation of the contraceptive efficacy of the levonorgestrel implant may be needed for efavirenz users.
Among 42 Malawian women using the levonorgestrel implant for contraception, women who were taking the antiretroviral efavirenz had lower serum levonorgestrel concentrations than women who were not taking efavirenz. However, none of the women who were taking efavirenz became pregnant over 60 women-years of follow-up.
我们的主要目标是比较植入左炔诺孕酮后长达30个月内，正在服用或未服用抗逆转录病毒药物依法韦仑的左炔诺孕酮植入剂使用者的几何平均左炔诺孕酮浓度。我们的次要目标是评估服用依法韦仑的左炔诺孕酮植入剂使用者的妊娠率。
我们对42名马拉维女性进行了亚组分析，这些女性作为一项随机临床试验的一部分被随机分配开始使用左炔诺孕酮植入剂。我们的亚组包括30名感染HIV且正在服用依法韦仑的女性和12名未感染HIV且未服用依法韦仑的女性。她们每3个月进行一次尿妊娠试验，并在植入后第3天以及第1、3、6、12、18、24、27和30个月进行血清左炔诺孕酮检测。计算每个时间点服用依法韦仑者和未服用依法韦仑者的几何平均左炔诺孕酮浓度。
在每个时间点，服用依法韦仑者的几何平均左炔诺孕酮浓度均低于未服用依法韦仑者；植入后1个月时，服用依法韦仑者与未服用依法韦仑者的几何平均比值为0.60[90%置信区间（CI）0.46 - 0.79]，至30个月时为0.27（90%CI 0.12 - 0.61）。在左炔诺孕酮植入剂与依法韦仑联合使用的60妇女年期间未发生妊娠，尽管有11名女性的左炔诺孕酮浓度<180 pg/mL（先前建议的有效最低阈值浓度）。
服用依法韦仑者的左炔诺孕酮浓度低于未服用依法韦仑者，且我们联合使用依法韦仑和左炔诺孕酮植入剂的使用者中有三分之一的浓度<180 pg/mL。对于服用依法韦仑者，可能需要持续评估左炔诺孕酮植入剂的避孕效果。
在42名使用左炔诺孕酮植入剂避孕的马拉维女性中，服用抗逆转录病毒药物依法韦仑的女性血清左炔诺孕酮浓度低于未服用依法韦仑的女性。然而，在60妇女年的随访中，服用依法韦仑的女性均未怀孕。
