Indications
Abemaciclib is a targeted cancer medicine used to treat hormone receptor positive (HR+), HER2 negative breast cancer. It is used for early breast cancer with a high risk of coming back, after surgery, together with hormone therapy, and for advanced or metastatic breast cancer (cancer that has spread), together with an aromatase inhibitor such as Letrozole or Anastrozole, or with Fulvestrant. In some cases it is used alone after other treatments.
How It Works
Cancer cells divide out of control. Abemaciclib blocks two enzymes called CDK4 and CDK6, which act like switches that push cells through the cycle of division. By turning these switches off, it stops breast cancer cells from growing and multiplying. Combined with hormone therapy, which removes the oestrogen signal that feeds these cancers, it slows the disease more than hormone therapy alone.
Dosage and Administration
Take exactly as prescribed by your cancer specialist (oncologist). It is a tablet taken by mouth, usually twice a day, about 12 hours apart, with or without food, swallowed whole. Your doctor may lower the dose or pause treatment if side effects occur. Do not eat grapefruit or drink grapefruit juice. If you vomit or miss a dose, take the next dose at the usual time; do not take an extra dose.
Interactions
- Strong CYP3A4 inhibitors such as Ketoconazole, Itraconazole, Clarithromycin and Ritonavir, and grapefruit, can greatly raise Abemaciclib levels and side effects.
- CYP3A4 inducers such as Rifampicin, Carbamazepine, Phenytoin and St John’s Wort can reduce its effect.
- It may increase levels of some medicines such as Metformin and Digoxin.
- Tell your oncologist about every medicine, herbal product and supplement you use.
Contraindications
Do not use if you are allergic to Abemaciclib or any ingredient in the tablet. It must not be used during pregnancy.
Side Effects
Common side effects include:
- Diarrhoea, which is very common, often in the first weeks
- Nausea, vomiting, stomach pain, reduced appetite
- Low white blood cells, red cells or platelets, increasing the risk of infection, tiredness or bruising
- Tiredness, headache, hair thinning
- Raised liver enzymes or creatinine on blood tests
At the first sign of loose stools, start the anti-diarrhoea medicine your doctor gave you, drink plenty of fluids and tell your care team. Get urgent medical help for fever of 38°C or above or chills, diarrhoea that does not settle within 24 hours or causes dizziness, breathlessness, cough or chest pain (possible lung inflammation), pain or swelling in the leg or sudden breathlessness (possible blood clot), yellow skin or eyes, or dark urine.
Pregnancy and Lactation
Abemaciclib can harm an unborn baby. Women who can become pregnant must use effective contraception during treatment and for at least 3 weeks after the last dose. Do not breastfeed during treatment and for at least 3 weeks after the last dose. It may affect fertility in men.
Precautions and Warnings
- Regular blood tests for blood counts and liver function are needed, especially in the first months.
- Report any signs of infection promptly.
- Use with care in liver or kidney disease and in people with a history of blood clots.
- Handle tablets carefully; do not crush or split them.
Overdose
Overdose may cause severe diarrhoea, tiredness and low blood counts. Contact your doctor or go to hospital immediately; treatment supports the body while the medicine clears.
Therapeutic Class
Antineoplastic, CDK4 and CDK6 inhibitor (targeted cancer therapy)
Storage
Store below 30°C in a dry place, in the original pack, 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.