Definition: A transdermal patch is a sticky patch that delivers a drug through unbroken skin into the blood over several days. The NCI defines transdermal as absorbed through the unbroken skin. Labels call these products a transdermal system; estradiol patches such as Climara and Vivelle-Dot are common examples.
| Patch | Contains | Changed |
|---|---|---|
| Climara, Menostar | Estradiol | Once a week |
| Climara Pro | Estradiol and levonorgestrel | Once a week |
| Vivelle-Dot, Minivelle | Estradiol | Twice a week, every 3 to 4 days |
| CombiPatch | Estradiol and norethindrone acetate | Twice a week, every 3 to 4 days |
The NCI Thesaurus describes an extended-release patch as one that releases drug at a controlled rate so it can be used less often than a pill.
The Climara label says clean, dry skin of the lower abdomen or upper buttock, never on or near the breasts and not at the waistline. Sites are rotated, with at least 1 week before the same site is used again, and the patch is pressed firmly for at least 10 seconds. Only one patch is worn at a time. On Vivelle-Dot, patch site redness and irritation were 3.2% or less.
Estradiol patches carry the same boxed warning as estrogen pills, on endometrial cancer, stroke and blood clots, probable dementia and breast cancer.
A twice-weekly patch falls on different weekdays than a weekly one, and sites rotate. Logging the change day and the site makes the next change easy to work out.
Read more on Dose Track: Can you swim or shower with an estrogen patch · Estrogen patch vs pill blood clot risk · Climara side effects · Vivelle-Dot side effects