Cetrolix

Indications

Cetrorelix Acetate is used in fertility treatment. In women having controlled ovarian stimulation for assisted reproduction (such as IVF or ICSI), it prevents the eggs from being released too early, before they can be collected.

How It Works

Cetrorelix is a gonadotropin-releasing hormone (GnRH) antagonist. It blocks GnRH receptors in the pituitary gland, quickly lowering the release of luteinising hormone (LH). This prevents the sudden LH surge that would otherwise trigger ovulation before the planned egg collection.

Dosage and Administration

Cetrorelix is given as an injection under the skin of the lower abdomen, as prescribed by the fertility specialist. The first injection is usually given by a doctor or nurse; after training, some women give later doses themselves. The timing (usually once daily from about day 5 or 6 of stimulation until the trigger injection) is set by the specialist. Change the injection site each day.

Interactions

No formal interaction studies have shown important interactions. It is used together with fertility hormones as part of the treatment plan. Tell your doctor about all other medicines.

Contraindications

Do not use if you are allergic to Cetrorelix, other GnRH analogues or mannitol, during pregnancy or breastfeeding, after the menopause, or with moderate to severe kidney or liver disease.

Side Effects

Common effects include redness, itching or swelling at the injection site, headache and nausea. Ovarian hyperstimulation syndrome (OHSS) can occur as part of the fertility treatment, causing stomach pain, bloating, nausea and weight gain.

Get urgent medical help if you have severe stomach pain or swelling, rapid weight gain, shortness of breath, very little urine, or signs of a severe allergic reaction such as swelling of the face or throat, difficulty breathing or a widespread rash.

Pregnancy and Lactation

It must not be used if you are already pregnant or breastfeeding. Pregnancy should be ruled out before treatment starts.

Precautions and Warnings

Tell the doctor about allergies, especially to similar hormones, or a history of severe allergic reactions. Use only under supervision of a fertility specialist with monitoring of follicles and hormone levels. Report symptoms of OHSS promptly.

Overdose

Overdose is unlikely to cause serious harm but may prolong the hormone-blocking effect. Contact your doctor.

Therapeutic Class

Gonadotropin-releasing hormone (GnRH) antagonist

Storage

Store as directed on the pack, usually in a refrigerator at 2 to 8°C, do not freeze, in the original carton to protect from light. Some packs may be kept at room temperature for a limited time; follow the label. Keep out of the reach of children.