title: Evaluating the efficacy and safety of a progestin- and estrogen-releasing ethylene vinyl acetate copolymer contraceptive vaginal ring.
abstract: BACKGROUND
  Multiple studies confirm the safety and efficacy of the combined ethinyl estradiol (EE) and etonogestrel contraceptive vaginal ring (NuvaRing®). Advantages of continuous drug delivery through the vagina compared to oral administration include stable levels of contraceptive steroids without the need for daily drug administration. Although the combined contraceptive vaginal ring (CCVR) avoids the problem of missed pills, clinical data do not support greater efficacy. Vaginal administration avoids first-pass hepatic effects; however, EE is a potent inducer of hepatic globulins regardless of the route of administration. Consequently, thromboembolic risk during CCVR use is similar to that with combined oral contraceptives. Some epidemiologic and database studies suggest that the risk of thromboembolism is increased among users of the CCVR compared to levonorgestrel-containing combined pills.
  
  
  METHODS
  This review examined the available literature for level 1 and level 2 evidence of the CCVR and its associated efficacy and safety. Studies are presented in table format with significant findings and conclusions described.
  
  
  CONCLUSIONS
  A prospective study with 33,235 woman-years of exposure and with greater ability to control for covariates did not demonstrate an elevation of risk. The safety profile of the CCVR appears to be the same as with other combined hormonal contraceptives.
authors.affiliation: Oregon Health and Science University, Department of Obstetrics and Gynecology , UHN-70, OHSU, 3181 SW Sam Jackson Park Road, Portland, OR 97239 , USA brian.trung.nguyen@gmail.com.
authors.forename: Brian Trung
authors.initials: BT
authors.lastname: Nguyen
authors.forename: Jeffrey T
authors.initials: JT
authors.lastname: Jensen
mesh_terms: D003274:Contraceptive Devices, Female / Q000009:adverse effects; D003277:Contraceptives, Oral, Combined / Q000008:administration & dosage / Q000009:adverse effects; D017135:Desogestrel / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D004338:Drug Combinations; D016503:Drug Delivery Systems; D004997:Ethinyl Estradiol / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D006801:Humans; D011145:Polyvinyls / Q000737:chemistry*; D012306:Risk
chemical_list: D003277:Contraceptives, Oral, Combined; D004338:Drug Combinations; C516519:NuvaRing; D011145:Polyvinyls; C016438:ethylenevinylacetate copolymer; D004997:Ethinyl Estradiol; D017135:Desogestrel
keywords: combined contraceptive vaginal ring; contraception; contraceptive failure; deep vein thrombosis; safety; venous thromboembolism