August 6, 2014 — Merck is warning that NuvaRing, a popular O-shaped contraceptive device, should not be used by women who smoke cigarettes, are over the age of 35 or have at least one serious medical condition.
In an advisory published July 30, Merck and Health Canada announced changes to the warning information and updated the list of potential adverse events.
New side effects linked to NuvaRing include systemic lupus erythematosus, Sydenham’s chorea, herpes gestationis, otosclerosis-related hearing loss, hepatocellular carcinoma, Crohn’s disease, colitis ulcerosa and angioedema.
NuvaRing should not be used by women with:
- Heart disease
- High blood pressure
- Abnormal blood-fat levels
- Blood clotting disorders
- Major surgery with prolonged immobilization
- Migraines with focal neurological symptoms
- Pancreatitis associated with high triglyceride levels
Similar warnings have also been added to the Prescribing Information for NuvaRing in the United States.
Merck is currently facing nearly 4,000 lawsuits from women in the U.S. who allege that the drug-maker failed to adequately warn about the increased risk of blood clots. In 2012, a study published in the British Medical Journal found that women on NuvaRing were twice as likely to develop blood clots compared to women on birth control containing levonorgestrel. Women on NuvaRing were 6.5-times more likely to develop blood clots than women who did not use birth control.