Sino-implant (II) — a levonorgestrel-releasing two-rod implant: systematic review of the randomized controlled trials

Abstract

Background Sino-implant (II) is a subdermal contraceptive implant manufactured in China. This two-rod levonorgestrel-releasing implant has the same amount of active ingredient (150 mg levonorgestrel) and mechanism of action as the widely available contraceptive implant Jadelle. We examined randomized controlled trials of Sino-implant (II) for effectiveness and side effects. Study design We searched electronic databases for studies of Sino-implant (II), and then restricted our review to randomized controlled trials. The primary outcome of this review was pregnancy. Results Four randomized trials with a total of 15,943 women assigned to Sino-implant (II) had first-year probabilities of pregnancy ranging from 0.0% to 0.1%. Cumulative probabilities of pregnancy during the four years of the product's approved duration of use were 0.9% and 1.06% in the two trials that presented date for four-year use. Five-year cumulative probabilities of pregnancy ranged from 0.7% to 2.1%. In one trial, the cumulative probability of pregnancy more than doubled during the fifth year (from 0.9% to 2.1%), which may be why the implant is approved for four years of use in China. Five-year cumulative probabilities of discontinuation due to menstrual problems ranged from 12.5% to 15.5% for Sino-implant (II). Conclusions Sino-implant (II) is one of the most effective contraceptives available today. These available clinical data, combined with independent laboratory testing, and the knowledge that 7 million women have used this method since 1994, support the safety and effectiveness of Sino-implant (II). The lower cost of Sino-implant (II) compared with other subdermal implants could improve access to implants in resource-constrained settings.

Criterios Médicos de elegibilidad para el uso de anticonceptivos de la OMS

“…Al igual que Jadelle®, está conformado por dos varillas de silicona que contienen 75 mg de levonorgestrel, pero a diferencia de éste, sólo está aprobado para ser usado por 4 años en vez de 5 años. (8) Las recomendaciones de uso por la OMS son las mismas que para el resto de los implantes, con seguridad y efectos colaterales similares a la de otros implantes de levonorgestrel en mujeres sanas. (8) En el año 2010, se publicó una revisión sistemática de los estudios controlados-randomizados existentes de Sino-Implant (II)®, incluyendo 4 estudios que en conjunto sumaban 15.953 mujeres asignadas a SinoImplant (II)®.…”

“…Los estudios descritos para SinoImplant (II)® se han realizado en población oriental, salvo 2 estudios realizados en África, pero que incluyeron solo un año de seguimiento a las usuarias. (8) Faltan por lo tanto más estudios para evaluar si su uso se puede prolongar hasta el quinto año.…”

Applying emerging science to contraception research: implications for the clinic

“…The latter is one of the most effective contraceptives available today and known as Jadelle Ò and its generic form: Sino-implant (II) [82]. Implanon Ò delivering etonogestrel and effective for 3 years has been recently modified and approved as Nexplanon Ò with an improved inserter, and radio-opaque in order to locate the implant on x-ray for easier removal [83].…”

Invisible contraceptive implants: a case report

“…Subcutaneous contraceptive implants were introduced more than 25 years ago with the promise of offering women a highly effective and ‘forgettable’ reversible contraceptive method requiring a minimal amount of effort from the user and provider once inserted 1. These oestrogen-free devices consist of a synthetic progestin that diffuses into the circulation to maintain adequate serum concentrations over the lifespan of the product.…”

“…These agents are made of non-biodegradable materials and so require removal following maximum duration of action, on experiencing unacceptable side effects or when return to fertility is desired. The most frequent side effect and the reason for discontinuation is unpredictable vaginal bleeding 1 4–6. Although the incidence of this side effect is difficult to estimate, inability to palpate or visualise these devices using different imaging techniques is still an issue that surrounds contraceptive implants.…”