NuvaRing

NuvaRing is the trade name for a vaginal ring combined hormonal contraceptive manufactured by Organon that is available by prescription. It is a flexible plastic ring that releases a low dose of a progestin and an estrogen over 3 weeks.

NuvaRing was first approved in The Netherlands on February 14, 2001, then by all 14 other countries then in the European Union on June 12, 2001, and in the United States by the FDA on October 3, 2001.^[1] NuvaRing was first marketed in the United States in July 2002, followed by several other European countries in late 2002.^[2] In March 2007, Organon announced the market launch of NuvaRing in Australia, bringing the total number of countries where NuvaRing is available to 32. NuvaRing is currently used by approximately 1.5 million women worldwide.^[3]

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Use

The currently approved NuvaRing regimen specifies insertion of the ring into the vagina for a three-week period, then removal of the ring for one week, during which the user will experience a menstrual period. The break week with NuvaRing is comparable to the placebo week for combined oral contraceptive pills ("the Pill"), and the contraceptive effect is maintained during this period. Extended use regimens (7-week, quarterly, or annual) involving back-to-back use of (2, 4, or 17) rings have been studied in clinical trials, but are not currently approved.^[4][5][6]

Insertion of the ring is comparable to insertion of other vaginal rings. The muscles of the vagina keep NuvaRing securely in place, even during exercise or sex. Women can check the contraceptive ring periodically with their finger. In rare instances, NuvaRing may fall out during sexual intercourse, while straining during a bowel movement, or while removing a tampon.^[7][8]

Contraceptive efficacy is not reduced if the ring is removed or accidentally expelled and is left outside of the vagina for less than three hours. If the ring has been out of the vagina for more than three continuous hours, contraceptive efficacy may be reduced and a backup method of contraception must be used until the ring has been used continuously for a subsequent seven days.^[7][8]

Benefits

The benefits of the ring include:

• once-a-month self-administered use offering convenience, ease of use and privacy (most users and most partners do not feel the ring, and of those who do, most do not object to it)^[9][10][11]
• lower estrogen exposure than with combined oral contraceptive pills or the contraceptive patch Ortho Evra.^[9][12][13]
• a low incidence of estrogenic side effects such as nausea and breast tenderness^[10][14]
• a low incidence of irregular bleeding despite its lower estrogen dose^[10][14]

Side effects

  In two large studies, over a one year period, 15.1% of users discontinued NuvaRing because of adverse events. Device-related adverse events (foreign body sensation, coital problem, or expulsion) were the most frequently reported adverse events that resulted in discontinuation (by 2.5% of users). Device-related adverse events were reported at least once during the one year study period by 4.4% of NuvaRing users.^[10]

The most common adverse events reported by 5 to 14% of the 2501 women who used NuvaRing in five clinical trials were: vaginitis (14.1%), headache (9.8%), upper respiratory tract infection (8.0%), leukorrhea (5.8%), sinusitis (5.7%), nausea (5.2%), and weight gain (4.9%).^[8][15][16] NuvaRing is weight neutral.^[17][18] Additional side effect information is provided in the NuvaRing full prescribing information.^[8][16]

Etonogestrel, the specific progestin used in NuvaRing, is the active metabolite of the inactive prodrug desogestrel, one of two third-generation progestins found in some epidemiological studies of combined oral contraceptive pills to be associated with a higher risk of venous thrombosis than combined oral contraceptive pills containing certain second-generation progestins. Because hormones are released continuously from NuvaRing, peak and total estrogen and progestin doses are significantly lower than with combined oral contraceptives, although it is not known whether this lowers the risk of blood clots.^[8]

Mechanism of action

Like all combined hormonal contraceptives, NuvaRing works primarily by preventing ovulation. A secondary mechanism of action is inhibition of sperm penetration by changes in the cervical mucus. Hormonal contraceptives also have effects on the endometrium that theoretically could affect implantation, however no scientific evidence indicates that prevention of implantation actually results from their use.^[19] NuvaRing should not be used if a woman is pregnant. There is however no known harm to the woman, the course of her pregnancy, or the fetus if NuvaRing is accidentally used during pregnancy.^[20]

NuvaRing delivers 120 µg of etonogestrel (a progestin) and 15 µg of ethinyl estradiol (an estrogen) each day of use.

References