Proper Use and Dosage of Combination Patches for Hormone Therapy
For combination hormone patches, apply one patch weekly for three consecutive weeks followed by one patch-free week for contraception, or follow continuous application for hormone replacement therapy with the lowest effective dose based on symptoms. 1, 2
Contraceptive Combination Patch (Ethinyl Estradiol/Norelgestromin)
Dosage and Application
- The contraceptive patch contains 0.6 mg norelgestromin and 0.75 mg ethinyl estradiol 1
- Apply one patch weekly for 3 consecutive weeks, followed by 1 patch-free week (during which withdrawal bleeding typically occurs) 1
- Patch size is approximately 1.75 × 1.75 inches 1
Application Sites
- Can be placed on: abdomen, upper torso, upper outer arm, or buttocks 1
- Avoid areas where clothing may rub against the patch
- Rotate application sites to prevent skin irritation
Efficacy and Considerations
- Typical use failure rate: 9% (perfect use: <1%) 1
- Not recommended for women weighing >90 kg (198 pounds) due to reduced efficacy 3
- Adhesion is generally good with only 1.8% of patches requiring replacement due to complete detachment 4
- Physical exercise, water immersion, and humid climates do not significantly affect patch adhesion 4, 3
Extended Use Option
- Extended regimen: Apply weekly for 12 consecutive weeks, followed by 1 patch-free week, then 3 more weekly applications 5
- Extended use results in fewer bleeding days (6 vs 14 days) and episodes (1 vs 3) compared to cyclic use 5
- May be preferred by women who want fewer menstrual periods
Hormone Replacement Therapy Patch (Estradiol/Norethindrone)
Dosage and Application
- For postmenopausal women with a uterus: Estrogen must be combined with progestin to reduce endometrial cancer risk 2
- For women without a uterus: Estrogen-only patch can be used 2
- Initial dosage range: 1-2 mg daily of estradiol, adjusted as necessary to control symptoms 2
- Use the lowest effective dose for the shortest duration consistent with treatment goals 2
Administration Guidelines
- For vasomotor symptoms and vaginal atrophy: Use lowest dose that controls symptoms 2
- For hypoestrogenism due to hypogonadism or primary ovarian failure: Start with 1-2 mg daily of estradiol 2
- For osteoporosis prevention: Use lowest effective dose (specific minimum not determined) 2
Monitoring and Follow-up
- Reevaluate periodically at 3-6 month intervals 2
- Attempt to discontinue or taper medication at 3-6 month intervals 2
- For women with intact uterus, perform appropriate diagnostic measures (e.g., endometrial sampling) for cases of persistent abnormal vaginal bleeding 2
Important Safety Considerations
Contraceptive Patch
- Higher estrogen exposure (1.6 times higher) compared to combined oral contraceptives 1
- Black box warning about possible increased risk of venous thromboembolism (VTE) compared to 20-35 μg COCs (odds ratios 1.2-2.2) 1
- Consider other contraceptive methods as first-line choices for patients with VTE risk factors 1
Hormone Replacement Therapy
- Transdermal estradiol may be preferred for hypertensive patients or those with higher thrombosis risk 6
- For women with an intact uterus, progesterone must be added to prevent endometrial hyperplasia 6
- Contraindications include: history of breast cancer, active thromboembolic disorders, history of arterial thrombotic disease, undiagnosed vaginal bleeding, and liver problems 6
Common Side Effects
- Breast tenderness, headaches, nausea, breakthrough bleeding/spotting 1, 4
- Application site reactions (may lead to discontinuation in some cases) 4
- For contraceptive patch: Menstrual disturbances including breakthrough bleeding/spotting and dysmenorrhea 4
The combination patch offers a convenient, once-weekly application that may improve adherence compared to daily methods, with studies showing nearly 90% perfect adherence across all age groups for contraceptive patches 3.