The Pharmacokinetics of 12 Week Continuous Patch Use

For women who are seeking alternatives to long-acting contraceptives, the oral contraceptive pill and the contraceptive ring are often prescribed in an extended manner (12 weeks straight). The contraceptive patch, however, is not routinely prescribed in this way. Concerns have been raised that hormone levels, in particular estrogen, are higher among patch users than those who use oral contraception or the vaginal ring and that this may contribute to an increased risk of clot. However, few studies have actually looked at these hormone levels in women with extended use of the contraceptive patch.

The investigators plan to enroll eligible women age 18-39 who are willing to use the contraceptive patch continuously for twelve weeks, and can adhere to the study requirements for follow-up. All participants will have weekly serum assessments of ethinyl estradiol and norelgestromin levels. The investigators will enroll 30 women, in anticipation of a 33% attrition rate, with the goal of obtaining completed data on 20 participants. The study duration for an individual participant will be 12 weeks and the duration of the entire study will be one year.

Inclusion criteria

• Willing and able to come to the clinic to have blood drawn weekly for 12 weeks, biweekly during weeks 4, 8, and 12, and for 3 days after the final patch is removed for blood draws for a total of 18 blood draws
• Willing and able to abstain from using any other hormonal contraceptive method while in the study and for the week prior to starting the study

Exclusion criteria

• Body Mass Index greater than 35
• Personal or Family History of Venothromboembolism
• Personal History of Migraines with Aura
• Personal History of Migraines without Aura
• Tobacco use greater than or equal to 15 cigarettes per day
• Current Pregnancy
• History of or Current Diagnosis of Cancer