Health and Nutrition >
Medicines >
E
Health Centres - Evra patches
What is it used for?
-
Contraception
How does it work?
Evra patches are contraceptive patches. They contain synthetic derivatives of the naturally occuring female sex hormones, oestrogen and progesterone. Ethinylestradiol (previously spelt ethinyloestradiol in the UK) is a synthetic version of oestrogen and norelgestromin is a synthetic form of progesterone. These hormones are similar to the hormones that are used in combined oral contraceptives (the pill) and work in the same way.
Hormonal contraceptives like Evra work by over-riding the normal menstrual cycle. In a woman's normal menstrual cycle, levels of the sex hormones change throughout each month. The hormones cause an egg to be released from the ovaries (ovulation) and prepare the lining of the womb for a possible pregnancy. At the end of each cycle, if the egg has not been fertilised the levels of the hormones fall, causing the womb lining to be shed as a monthly period.
The hormones that are absorbed into your bloodstream from the patch work mainly by tricking your body into thinking that ovulation has already happened. This prevents an egg from ripening and being released from the ovaries each month.
The hormones also increase the thickness of the natural mucus at the neck of the womb, which makes it more difficult for sperm to cross from the vagina into the womb and reach an egg. They also change the quality of the womb lining (endometrium), making it less likely that a fertilised egg can implant there.
Evra patches are designed to be used for three weeks out of every four. One patch should be applied to the skin once a week, on the same day each week (known as the "Change Day"), for three weeks. During this time the hormones are absorbed from the patch through the skin and into the bloodstream, at a continuous rate. In the fourth week of the monthly cycle you don't wear a patch. During your week off, the levels of the hormones in your blood drop, which results in a withdrawal bleed that is similar to your normal period.
A new contraceptive cycle begins on the next day following your patch-free week (ie same day as your "Change Day"). A new patch should be applied even if you have had no bleeding in the patch-free week, or if bleeding has not yet stopped.
You will still be protected against pregnancy in your patch-free week, provided you used the previous three patches correctly, you start the next cycle of patches on time and nothing else happened that could make the patch less effective (eg taking certain other medicines - see below).
When can I start using it?
The information and advice that we give below with regards starting the patches may conflict with the information you will find in the manufacturer's leaflet provided with your patches.
However, the information we give is the same as the UK fpa (formerly The Family Planning Association) recommendations, which are based on systematic reviews of the currently available evidence. If you are concerned or have any questions, you can ask your doctor, nurse, pharmacist or local family planning centre for advice.
Ideally, you should start using Evra on day one of your menstrual cycle (the first day of your period). This will protect you from pregnancy immediately and you won't need to use any additional methods of contraception. If necessary, you can also start using it on up to day five of your cycle without needing to use additional contraception when you start. However, if you have a short menstrual cycle (with your period coming every 23 days or less), starting as late as the fifth day of your cycle may not provide you with immediate contraceptive protection. You should talk to your doctor or nurse about this and whether you need to use an additional contraceptive method for the first seven days.
You can also start using the patch at any other time in your cycle if your doctor is reasonably sure that you are not pregnant. However, if you start using the patch at any other time in your cycle, you won't be protected from pregnancy straight away and you will need to use additional contraception, eg condoms (or not have sex) for the first seven days.
If you have given birth and are not breastfeeding, you can start using this patch on day 21 after the birth. You will be protected against pregnancy immediately and do not need to use extra contraception. If you start using it later than 21 days after giving birth, you will need to use extra contraception (or not have sex) for the first seven days.
If you are starting the patch immediately after a miscarriage or abortion at under 24 weeks, you will protected against pregnancy immediately. If you start using it more than seven days after the miscarriage or abortion, you should use extra contraception for the first seven days.
How do I use the patches?
. Follow the instructions in the leaflet provided with your patches carefully. Only one patch should be applied at a time. The patch should be applied to clean, dry, hairless, intact, healthy skin on the buttock, abdomen, upper outer arm or upper torso, in a place where it will not be rubbed by tight clothing. It should NOT be applied to the breasts or to skin that is red, irritated or broken. On your "Change Day", remove the old patch and replace it with a new one in a slightly different area to avoid irritating the same area of skin.
Avoid using make-up, creams, lotions, powders or other products on the area of skin where you are going to apply a patch, as this may stop it sticking properly. You should not use extra adhesives or bandages to hold your patch in place.
© Copyright 1998 - 2009 NetDoctor.co.uk - All rights reserved 
