The primary aim of this study is to determine and compare changes in plasma concentration of levonorgestrel after sugammadex (intervention) or neostigmine (control).
There are no published studies on exogenous hormone changes in relation to sugammadex administration in women who take hormonal contraception. This study will determine if sugammadex or neostigmine affects the serum concentration of levonorgestrel – Australia’s most common hormonal contraceptive listed on the Pharmaceutical Benefits Scheme. It will also determine if ovulation has occurred in the post-operative period for a sub-group of participants, which would indicate contraceptive failure.
Hypotheses: Serum concentrations of levonorgestrel may be reduced after exposure to sugammadex to a degree that risks contraceptive failure and unintended pregnancy in female patients.
The information generated from this research project will produce scientific evidence to address the current global concerns about contraception efficacy after sugammadex administration. If a significant change in plasma hormone concentrations does not exist, then this will provide clinicians with the confidence to use this drug in young females without fear of a threat to contraception and unintended pregnancy and is a step closer to gender equality in health.
This study is part of a PhD for Dr Tamblyn Devoy through the University of Wollongong, NSW, Australia.
Dr Tamblyn Devoy, A/Professor Natalie Smith, Wollongong Hospital, NSW.
The project was awarded A$61,150 funding through the ANZCA research grants program for 2026.