Portal de Periódicos da CAPES

Review of the vaginal contraceptive ring (NuvaRing<SUP>®</SUP>)

2008; BMJ; Volume: 34; Issue: 4 Linguagem: Inglês

10.1783/147118908786000370

2045-2098

Noa’a Shimoni, Carolyn Westhoff,

Sexual function and dysfunction studies

OverviewThe forthcoming introduction of the vaginal contraceptive ring into the British market provides another contraceptive choice for women.In this review of the ring we highlight the current scientific literature and describe our experience in the USA over the past 7 years.The vaginal contraceptive ring (NuvaRing ® , Organon, Oss, The Netherlands) is a flexible, latex-free ring made of the plastic, ethylene vinyl acetate, which releases 120 µg etonogestrel (the biologically active metabolite of desogestrel) and 15 µg ethinylestradiol (EE) daily.The ring is 54 mm in diameter and 4 mm thick.The ring is placed vaginally once every 3 weeks by the woman and hormone is continuously absorbed through the vaginal mucosa.The ring is removed after 3 weeks, and following a 1-week ring-free interval a new ring is inserted.In common with the contraceptive patch and oral contraceptive pills (OCPs) the ring's effects are systemic.Vaginal administration has the potential benefits of avoiding oral administration and hence issues related to broad-spectrum antibiotic interactions and potential lack of efficacy from gastrointestinal upsets.By avoiding first-pass hepatic metabolism, lower doses of hormones can be used to provide effective contraception. Search strategyWe conducted a MEDLINE search from 1950 to May 2008 using the keywords 'vaginal ring' and 'NuvaRing'.This search identified 292 publications, which were then evaluated for relevance.Additional references from the authors' files were reviewed also. EfficacyThe ring's effectiveness is similar to other combined hormonal contraceptive methods, with pregnancy rates less than 1% in large efficacy trials.Increased effectiveness may result from ease of use and the minimal user intervention required.Four efficacy trials supported by Organon, the developer and manufacturer of the ring, all showed pregnancy rates similar to combined oral contraceptive (COC) pills.Two open-label, non-comparative efficacy studies were performed and analysed together.One study was performed in 52 European centres, with the second carried out in 48 centres in Canada and the USA. 1,2A total of 2322 women aged 18-40 years in need of contraception were recruited.The studies assessed efficacy over 13 cycles.Compliance with ring use was defined as use for 3 weeks ± 48 hours, and the ring-free period did not deviate by more Review of the vaginal contraceptive ring (NuvaRing ® )