Ribociclib
Indications
Ribociclib is an anticancer medicine used to treat hormone receptor positive (HR positive), HER2 negative breast cancer that is advanced or has spread (metastatic), together with hormone therapy such as an aromatase inhibitor (for example Letrozole) or Fulvestrant. It is also used with an aromatase inhibitor after surgery in some people with early breast cancer at high risk of coming back.
How It Works
Cells use proteins called cyclin-dependent kinases 4 and 6 (CDK4/6) to move from a resting phase into the phase where they copy their DNA and divide. In hormone-sensitive breast cancer these proteins are overactive. Ribociclib blocks CDK4/6, which stops cancer cells from dividing and slows tumour growth; combined with hormone therapy it works better than hormone therapy alone.
Dosage and Administration
Ribociclib is taken by mouth as prescribed by a cancer specialist, usually once a day for 21 days followed by 7 days off, in 28-day cycles, with or without food, at about the same time each day. Tablets are swallowed whole. The dose may be reduced or paused depending on blood counts, liver tests, ECG and side effects. Women who have not gone through menopause also receive treatment to stop ovarian function. Do not take an extra dose if one is missed or vomited.
Interactions
- Strong CYP3A4 inhibitors (Clarithromycin, Itraconazole, Ketoconazole, Ritonavir) and grapefruit or grapefruit juice raise Ribociclib levels; avoid.
- Strong CYP3A4 inducers (Rifampicin, Phenytoin, Carbamazepine, St John's Wort) lower its effect; avoid.
- Medicines that prolong the QT interval (such as Amiodarone, some antipsychotics, Ondansetron at high doses, Moxifloxacin) increase heart rhythm risk.
- It raises levels of some medicines broken down by CYP3A4, such as Midazolam, Simvastatin, Tacrolimus and Ciclosporin.
- Tamoxifen is not used with Ribociclib.
Contraindications
- Allergy to Ribociclib, peanut or soya (some tablets contain soya lecithin).
- Long QT syndrome or uncorrected heart rhythm problems, as judged by the doctor.
- Pregnancy.
Side Effects
Common: low white blood cell count (neutropenia), tiredness, nausea, diarrhoea, vomiting, hair thinning, headache, back pain, mouth sores, rash, cough and raised liver enzymes. ECG changes (QT prolongation) can occur.
Get urgent medical help for fever or chills (possible serious infection), fainting, palpitations or a fast irregular heartbeat, yellowing of the skin or eyes, dark urine, severe stomach pain, new or worsening cough or breathlessness (possible lung inflammation), or a severe blistering rash.
Pregnancy and Lactation
Ribociclib can harm an unborn baby. Women who could become pregnant must use effective contraception during treatment and for at least 21 days after the last dose. Do not breastfeed during treatment and for at least 21 days after the last dose.
Precautions and Warnings
- Blood counts, liver tests, salts and ECGs are checked before and regularly during treatment.
- Tell the doctor about heart disease, low potassium or magnesium, liver disease and all medicines and supplements.
- Avoid grapefruit and herbal products unless the doctor approves.
- Report any signs of infection early.
Overdose
Overdose may cause severe nausea, vomiting, low blood counts and dangerous heart rhythm changes. Seek emergency medical help; ECG monitoring and supportive care are given in hospital.
Therapeutic Class
Antineoplastic, cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor.
Storage
Store below 30°C in the original blister pack to protect from moisture, away from light and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.
All brands of Ribociclib