The short answer
During many general anaesthetics you are given a muscle relaxant. At the end of the operation, a medicine called sugammadex may be used to reverse it so your muscles work normally again before you wake up fully.
Sugammadex can also pick up some of the hormone progestogen in your blood. Progestogen is in most hormonal contraception. For a short time this can make your contraception less reliable. The medicine information approved in Australia treats this as the same as missing one contraceptive pill.
If you had sugammadex and you use hormonal contraception, keep using your contraception as normal and use condoms as well for the next 7 days.
Why it happens
Sugammadex is shaped like a tiny ring. It works by wrapping around the muscle relaxant and carrying it out of the body in your urine. Progestogen has a similar shape, so the ring can also catch some of it. This lowers the hormone level for a short time, much as taking a pill late does. Sugammadex leaves the body within about a day.
This is the only medicine commonly used in an anaesthetic that is known to affect hormonal contraception in this way. It does not cause any lasting effect on your fertility or your contraception.
Before your anaesthetic
- Tell Dr Halvey which contraception you use, including an implant, hormonal coil, injection, ring or patch. You can tell him privately if you prefer.
- Keep taking your pill as usual before surgery, unless you have been told otherwise.
- If you would rather sugammadex was not used, tell Dr Halvey. In many operations an older reversal medicine, neostigmine, can be used instead. It does not affect contraception. Dr Halvey will explain whether it suits your operation.
- If there is any chance you are pregnant, tell the team before your anaesthetic.
After your anaesthetic
Dr Halvey or the recovery nurse will tell you if you were given sugammadex, and you will be given written information. If you are not sure whether you had it, ask before you go home, or contact the rooms.
Anaesthetic medicines can affect your memory of conversations on the day, so keep this page or the leaflet you are given.
What to do, by type of contraception
The advice is to keep using your usual method and add condoms for 7 days after the day you had sugammadex. Do not stop your usual contraception.
| Contraception | What to do |
|---|---|
| Combined pill | Keep taking your pill at the usual time. Count the day of your operation as one missed pill and follow the missed pill advice in your pill leaflet. Use condoms as well for 7 days. |
| Progestogen-only pill (mini-pill) | Keep taking your pill at the usual time. Count the day of your operation as one missed pill. Use condoms as well for 7 days. |
| Implant (Implanon NXT) | Leave it in place. Use condoms as well for 7 days. |
| Hormonal coil (Mirena, Kyleena) | Leave it in place. Use condoms as well for 7 days. Most of this hormone works inside the womb, so the effect is expected to be small. |
| Contraceptive injection (Depo-Provera) | Have your next injection on time. Use condoms as well for 7 days. Hormone levels from the injection are high, so the effect is expected to be small. |
| Vaginal ring (NuvaRing) | Keep using your ring as normal. Use condoms as well for 7 days. |
| Copper coil | No change needed. It does not contain hormones. |
| Condoms or other non-hormonal methods | No change needed. |
If you have had sex without a condom
If you had sex without a condom in the 7 days after your anaesthetic, speak to a pharmacist, your GP or a sexual health service as soon as you can about emergency contraception. In Australia, emergency contraceptive pills are available from a pharmacist without a prescription. They work best the sooner they are taken. A copper coil fitted by a doctor is also an option.
If your period is late or you think you might be pregnant, do a pregnancy test and see your GP.
How sure are we about this?
The advice comes from laboratory tests and computer modelling done by the manufacturer. Studies in women who had sugammadex have so far found smaller changes in hormone levels than the models predicted. There is no clear proof that sugammadex has caused pregnancies.
Because an unplanned pregnancy matters a great deal, the approved medicine information still asks every person using hormonal contraception to follow the 7 day advice, and Dr Halvey follows it too.
Who to ask
- Dr Halvey, before or after your operation.
- Your community pharmacist or GP once you are home.
- A sexual health service, such as Sexual Health Quarters (SHQ) in Perth.
- healthdirect: 1800 022 222, at any time.