Rachel Dyer, Nurse Practitioner ACU, talks to an Altrui donor about how to use Cetrotide in the egg donation process.

The interview was held at the Assisted Conception Unit Guy’s & St Thomas’ Hospital, London.

Cetrotide is one of the drugs prescribed in the egg donation treatment cycle. As the follicles develop and get larger, the ovary will naturally trigger a response to the developing follicles and release the eggs in ovulation. Cetrotide is taken for approximately six days suppressing the natural hormones, which ensures that the growing eggs are not released prematurely. This enables them to be surgically removed when the time is right.

How Cetrotide works
Cetrotide is used together with another hormone called Follicle Stimulating Hormone (FSH) in the treatment of infertility in women having assisted reproduction treatment, such as IVF and egg donation.

Cetrotide injections contain the active ingredient Cetrorelix, which is a synthetic form of a natural hormone called Gonadotrophin Releasing Hormone (GnRH). GnRH induces the production and release of Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH) from the pituitary gland in the brain.

Normally in the ovaries FSH increases the number of growing follicles and stimulates their development. Within the follicles are the developing eggs. FSH also increases the production of oestrogen, and under the influence of this hormone, the largest follicle continues to develop. As the amount of oestrogen in the blood increases, at mid-cycle, the amount of GnRH also increases resulting in a surge of LH. This LH surge induces the ovulation (the release of an egg) of the dominant follicle.

Cetrotide competes with natural GnRH in the pituitary gland and thus controls the release of LH and FSH. This prevents a premature surge of LH and allows all the follicles to develop fully. When enough large follicles have developed, ovulation is then induced artificially with an injection of another hormone called Human Chorionic Gonadotrophin (HCG), and the eggs are then collected.

Cetrotide injection

>> Nurse Dyer: What we tend to do is get you back here for a blood test on day five to check your response. Then, based on that result, we will then call you back, informing you if the dose of the Gonal-F needs to be changed. The following day, so normally about day six or day seven of your medication, you need to take another drug called Cetrotide, which is this drug here. What this drug does, it stops the eggs from being released prematurely. Again it’s an injection. Unfortunately, though, you do have to mix it, so it’s unlike the Gonal-F, which is prefilled; this one you have to mix together. Again it’s subcutaneous. It’s taken once daily. It is preferred to be taken in the morning and it is preferred to be taken into the tummy – again similar area as you do the Gonal-F. I tend to say, “When you do the both injections, take them both on the same side,” so both on the right side so you have one side that you’re actively using; the other side is recovering and not too sore, because otherwise if we try and do it all over your tummy, your whole tummy might feel a little bit uncomfortable.

>> Egg Donor: Is the needle the same size on this one as the pen?

>> Nurse Dyer: It’s slightly different, only because it’s a different brand type. However, it’s still a subcutaneous medication. It does look longer and people do get concerned that it appears longer and thinking it’s going to be more uncomfortable, but it’s not the needle that’s uncomfortable, it’s more the medication. This medication, unlike the Gonal-F, does sting a little bit, has a tendency to sting and also has a tendency to cause like a local irritation on some people’s abdomens. Some people, every time when they take this injection, will get like a red inflammation site, or some people might just get it for the first few days and then it goes away, but some people do get it every single day. It’s not anything serious; it’s just some component in the medication that causes that for quite a few people. It normally goes away without anything that you have to do; it will normally just go away by its own accord.

The Cetrotide comes with a prefilled pen that has the liquid inside, and then it has the powder, which is the medication, here, and it has two needles that you need that you will use to mix the medication. You have two needles; the large yellow one is for mixing. Unscrew the white cover. You attach the needle, take the cap off the powder, and then place the needle through the centre. Then inject and just allow a few seconds for it to dissolve.

This is a stubborn one (Laughter). Then you can draw it back up, so literally place the needle in, draw it back up into your syringe. Take off this needle. You’re going to put the injecting needle on, so twist this off. Then you hold it upright, you flick to get rid of any air bubbles, taking off the cover.

This needle does look longer than the other one, but it’s just the different brand type, basically. The purpose of taking the Cetrotide is to stop the follicles from being released prematurely. As we know, once the follicles get to about 40mm in size, you in your body develop a [surge 0:04:20], or you can develop a [surge] and therefore we’ve lost the follicles that we wanted to collect, so this is your control drug and it stops the…>> Egg Donor: That’s basically stopping you bleeding, is that what it’s doing?>> Nurse Dyer: No, it’s stopping you ovulating. Normally follicles, once they get to a certain size of maturity, the body kicks in with another hormone. That makes you ovulate and this is to stop that ovulation occurring, because we want to take you to theatre on a specific date and time and collect the eggs; otherwise, we’ve lost control of the whole cycle.