engleski

Influence of ultrasound on the release of levonorgestrel from a hormonal intrauterine device Mirena

Mirena is a hormonal intrauterine device, or IUD, that can be used for long-term birth control and to treat heavy periods. Mirena birth control works by releasing levonorgestrel. Levonorgestrel is a progestogen used in a variety of contraceptive products. Low doses of levonorgestrel can be administered into the uterine cavity with the Mirena intrauterine delivery system. Initially, levonorgestrel is released at a rate of approximately 20 μg/day. This rate decreases progressively to half that value after 5 years. Ultrasonography plays an essential role in evaluating IUD position and assessing for complications [1, 2]. The aim of this study was to investigate whether the frequent use of ultrasound to control Mirena's position could influence on the increased release of levonorgestrel from a hormonal intrauterine device Mirena. In order to check whether ultrasound had an effect on increased hormone release from IUD Mirena the following experiment was performed. To simulate the real situation of placing Mirena into the uterine cavity in woman's body, we placed a new Mirena in a 50 mL plastic container and added 0.9% saline solution. Each container had an acoustic window made of thin plastic film, onto which we placed an ultrasonic transducer over the gel. As ultrasound source, we used NPL's continuous- wave checksource which operates at a fixed frequency of 3.5 MHz [3]. The device has three switchable settings, allowing nominal powers of 10 mW, 100 mW and 1 W to be applied. The NPL Checksource essentially covers the diagnostic and low therapy power range. We exposure to ultrasound waves 11 samples (containers with Mirena and saline solutions). We varied the exposure time from 1 min to 30 min and we varied applied ultrasound power. After exposure to ultrasound, Mirene were removed from the containers and saline samples were analysed by Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) to quantify levonorgestrel. The results of our measurements showed that ultrasound did not have a statistically significant effect on the increased release of levonorgestrel from a hormonal intrauterine device Mirena.

Ultrasound ; hormonal intrauterine device ; Levonorgestrel ; ultrasound effect

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