Ribociclib belongs the group of cancer-fighting medications known as antineoplastics and more specifically to a class of medications called protein kinase inhibitors. These medications are antitumour medications that work directly on cancer cells to slow down the speed at which they grow and slow down the growth of the tumour.

Ribociclib is used to treat breast cancer that has specific characteristics. It is used to treat breast cancer that is advanced or has metastasized (spread to other parts of the body) and is hormone receptor (HR) positive and human epidermal growth factor receptor 2 (HER-2) negative. Ribociclib is used in combination with other hormone therapies.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended dose of ribociclib is 600 mg (3 x 200 mg tablets) taken by mouth, once a day. It may be taken with food or on an empty stomach, but it should be taken at approximately the same time each day. Swallow the tablets whole with a glass of water. They must not be crushed or broken. If you find any tablets that have been cracked or broken, do not take them.

Ribociclib is taken daily for 21 days, followed by 7 days off. This forms a treatment cycle of 28 days which is then repeated as long as the medication is working for you.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor.

If you miss a dose or vomit after taking the tablet, skip that dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature in its original package, protect it from light and moisture, and keep it out of the reach of children.

Each light greyish violet, unscored, round, film-coated tablet, curved with bevelled edges, debossed with "RIC" on one side and "NVR" on the other side contains 200 mg ribociclib (as ribociclib succinate). Nonmedicinal ingredients: colloidal silicon dioxide, crospovidone (Type A, low-substituted hydroxypropylcellulose, magnesium stearate, and microcrystalline cellulose; Coating material: iron oxide black (E172), iron oxide red (E172), lecithin (soy) (E322), polyvinyl alcohol (partially hydrolysed), talc, titanium dioxide (E171), and xanthan gum.

Do not take this medication if you:

• are allergic to ribociclib or any ingredients of the medication
• have untreated long QT syndrome (a type of irregular heartbeat) or are at risk of developing long QT syndrome

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal pain
• back pain
• balance problems
• changed sense of taste
• constipation
• cough
• diarrhea
• dizziness
• dry eyes
• dry mouth
• dry skin
• hair loss or thinning
• headache
• head or neck pain
• heartburn
• increased cold- or flu-like symptoms (e.g., nasal congestion, runny nose, sore throat, fatigue)
• increased watering or tearing of eyes
• itchiness
• lightheadedness
• loss of appetite
• loss of skin colour in patches (vitiligo)
• mouth sores, swollen, red gums
• nausea
• skin rash
• skin reddening
• sore throat
• tiredness
• trouble sleeping
• vomiting
• weakness

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• fainting
• fever over 38°C for longer than 1 hour or over 38.3°C at any time
• shortness of breath or difficulty breathing
• signs of anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• signs of a blood clot in the arm or leg (tenderness, pain, swelling, warmth, or redness in the arm or leg)
• signs of dehydration (e.g., decreased urine, dry skin, dry and sticky mouth, sleepiness, dizziness, headache, thirst, confusion)
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• signs of infection (symptoms may include fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness)
• signs of liver problems (e.g., yellowing of skin and eyes, dark urine, light-coloured stools, nausea, vomiting, and stomach pains)
• signs of low blood calcium levels (e.g., muscle spasms, tingling or numbness of the fingers and mouth, twitching, or memory loss)
• signs of low potassium levels in the blood (e.g., weakness, fatigue, muscle cramps, irregular heartbeat)
• signs of infection in the stomach or intestines (e.g., diarrhea, nausea, vomiting, abdominal pain)
• spinning sensation
• swollen hands or feet
• symptoms of irregular heartbeat (e.g., chest pain, dizziness, rapid, pounding heartbeat, shortness of breath)
• symptoms of lung inflammation (e.g., trouble breathing, cough, shortness of breath, feeling tired, fever)
• symptoms of pneumonia (e.g., chest pain with breathing or coughing, confusion, fatigue, fever, sweating and shaking, chills, nausea, vomiting, diarrhea, shortness of breath)
•  symptoms of a urinary tract infection (e.g., pain when urinating, urinating more often than usual, low back or flank pain)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of bleeding in the stomach or lung (e.g., bloody, black, or tarry stools; spitting or coughing up blood; vomiting blood or material that looks like coffee grounds)
• signs of a blood clot in the lungs (difficulty breathing, sharp chest pain that is worst when breathing in, coughing, coughing up blood, sweating, or passing out)
• signs of sepsis (blood infection; e.g., fever, dizziness, chills, very high or very low body temperature, low blood pressure, pounding or rapid heartbeat, rapid, shallow breathing)
• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Abnormal heart rhythms: This medication can cause a heart rhythm problem called QT prolongation or long QT syndrome. If you have a history of QT prolongation that is being treated with medication, slow or irregular heart rhythm, heart failure, heart attack or heart disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you are taking other medications known to cause QT prolongation or have a family history of sudden cardiac death at less than 50 years of age, talk to your doctor. This medication is not recommended for people who are at risk of developing abnormal heart rhythms.

Anemia: Ribociclib may cause low levels of red blood cells. If you experience symptoms of reduced red blood cell count (anemia) such as shortness of breath, feeling unusually tired, or pale skin, contact your doctor as soon as possible.

Your doctor will do blood tests regularly to monitor the number of specific types of blood cells, including red blood cells, in your blood.

Bleeding: Ribociclib may cause a reduced number of platelets in the blood, which can make it difficult to stop cuts from bleeding. If you notice any signs of bleeding, such as frequent nosebleeds, unexplained bruising, or black and tarry stools, notify your doctor as soon as possible. Your doctor will order routine blood tests to make sure potential problems are caught early.

Blood clots: This medication may increase the chance of blood clot formation, causing reduction of blood flow to organs or the extremities.

If you have a history of clotting you may be at increased risk of experiencing blood clot-related problems such as heart attack, stroke, or clots in the deep veins of your leg. Discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you experience symptoms such as sharp pain and swelling in the leg, difficulty breathing, chest pain, blurred vision or difficulty speaking, contact your doctor immediately.

Drowsiness/dizziness: Ribociclib may cause drowsiness or dizziness, affecting your ability to drive or operate machinery. Avoid driving, operating machinery, or performing other potentially hazardous tasks until you have determined how you are affected by this medication.

Infection: As well as killing cancer cells, ribociclib can reduce the number of cells that fight infection in the body (white blood cells). If possible, avoid contact with people with contagious infections. Tell your doctor immediately if you notice signs of an infection, such as fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness. Your doctor will do blood tests regularly to monitor the number of specific types of blood cells in your blood.

Interactions with food: Grapefruit and pomegranates affect how ribociclib is removed from the body. Consuming these fruits or their juices while taking ribociclib may cause the medication to build up in the body and cause possibly harmful side effects. Avoid these foods while taking this medication for treatment.

Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking this medication.

If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Lung inflammation: Ribociclib may cause inflammation of the lungs, known as pneumonitis, or interstitial lung disease (ILD). Symptoms of ILD include shortness of breath; a dry, hacking cough; weight loss; reduced or no appetite; extreme tiredness; and difficulty breathing. Depending on how severe the inflammation is, this can become a life-threatening illness. Report any symptoms of breathing difficulty to your doctor as soon as possible.

Pregnancy: This medication may cause harm to the developing baby if it is taken during pregnancy. People who could become pregnant and who are taking ribociclib should use a barrier form of birth control, such as condoms, while taking the medication and for at least 21 days after the last dose. This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if ribociclib passes into breast milk. If you are breast-feeding and taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding, as it is recommended that breast-feeding be stopped while taking ribociclib and for at least 21 days after the last dose.

Children: The safety and effectiveness of using this medication have not been established for children.

There may be an interaction between ribociclib and any of the following:

• abrocitinib
• alitretinoin
• alpha-blockers (e.g., alfuzosin, silodosin, tamsulosin)
• aminosalicylate drugs (e.g., mesalamine, olsalazine, sulfasalazine)
• anagrelide
• antiarrhythmics (e.g., amiodarone, disopyramide, dronedarone, flecainide, lidocaine, procainamide, propafenone, sotalol)
• anti-cancer medications (e.g., docetaxel, doxorubicin, etoposide, ifosfamide, irinotecan, venetoclax, vincristine)
• antipsychotics (e.g., aripiprazole, cariprazine, chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
• apalutamide
• apixaban
• aprepitant
• atogepant
• avacopan
• "azole" antifungals (e.g., fluconazole, itraconazole, ketoconazole, voriconazole)
• baricitinib
• benzodiazepines (e.g., alprazolam, diazepam, triazolam)
• beta-2 agonists (e.g., salmeterol, vilanterol)
• bosentan
• bromocriptine
• buspirone
• caffeine
• calcitriol
• calcium channel blockers (e.g., amlodipine, diltiazem, nifedipine, verapamil)
• cannabis
• CF transmembrane regulators (e.g., ivacaftor, lumacaftor, tezacaftor)
• chloroquine
• cladribine
• clindamycin
• clomipramine
• cobicistat
• colchicine
• corticosteroids (e.g., budesonide, dexamethasone, fluticasone, methylprednisolone)
• cyclosporine
• daridorexant
• darifenacin
• deferiprone
• denosumab
• deucravacitinib
• dienogest
• domperidone
• doxepin
• elagolix
• eletriptan
• eliglustat
• enzalutamide
• eplerenone
• ergot alkaloids (e.g., dihydroergotamine, ergonovine, ergotamine)
• estrogens (e.g., conjugated estrogen, estradiol, ethinyl estradiol)
• everolimus
• finerenone
• flibanserin
• general anesthetics (medications used to put people to sleep before surgery)
• grapefruit juice
• guanfacine
• HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., efavirenz, etravirine)
• HIV protease inhibitors (e.g., atazanavir, darunavir, lopinavir, ritonavir, tenofovir)
• imipramine
• inotuzumab
• ivabradine
• leflunomide
• lemborexant
• lenvatinib
• letermovir
• lomitapide
• macitentan
• macrolide antibiotics (e.g., azithromycin, clarithromycin, erythromycin)
• maraviroc
• mavacamten
• mefloquine
• metformin
• methadone
• mifepristone
• modafinil
• naloxegol
• narcotic pain relievers (e.g., codeine, fentanyl, hydrocodone, oxycodone, tramadol)
• natalizumab
• nirmatrelvir and ritonavir
• ocrelizumab
• ofatumumab
• ondansetron
• phosphodiesterase-5 inhibitors (e.g., sildenafil, tadalafil, vardenafil)
• pentamidine
• pimecrolimus
• praziquantel
• protein kinase inhibitors (e.g., bosutinib, dabrafenib, dasatinib, idelalisib, imatinib, nilotinib, tofacitinib)
• quinine
• quinolone antibiotics (e.g., levofloxacin, moxifloxacin)
• ranolazine
• rifabutin
• rifampin
• rivaroxaban
• roflumilast
• rupatadine
• St. John's wort
• saxagliptin
• seizure medications (e.g., carbamazepine, phenobarbital, phenytoin, primidone)
• selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, escitalopram)
• sirolimus
• solifenacin
• sphingosine 1-phosphate (S1P) receptor inhibitors (e.g., fingolimod, ponesimod, siponimod)
• "statin" anti-cholesterol medications (e.g., atorvastatin, lovastatin, simvastatin)
• tacrolimus
• tamoxifen
• ticagrelor
• tolterodine
• tolvaptan
• trazodone
• vaccines
• venetoclax
• vilazodone
• zopiclone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.