Ribociclib and letrozole (Oral)

Generic name: ribociclib and letrozole [ rye-boe-SYE-klib, LET-roe-zole ]
Brand name: Kisqali Femara Co-Pack
Drug class: Antineoplastic combinations

Medically reviewed by Drugs.com. Last updated on Jul 3, 2024.

Uses for ribociclib and letrozole

Ribociclib and letrozole combination is used to treat hormone receptor (HR)-positive, HER-2 negative advanced or metastatic (cancer that has spread) breast cancer in pre/perimenopausal women, postmenopausal women, or men.

Ribociclib belongs to the group of medicines called antineoplastics. It interferes with the growth of cancer cells, which are eventually destroyed. Since the growth of normal cells may also be affected by the medicine, other unwanted effects will also occur. Some of these may be serious and must be reported to your doctor.

Some hormones that occur naturally in the body can increase the growth of some breast cancers. Letrozole works by decreasing the amounts of these hormones in the body.

This medicine is available only with your doctor's prescription.

Before using ribociclib and letrozole

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of ribociclib and letrozole combination in the pediatric population. Safety and efficacy have not been established.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of ribociclib and letrozole combination in the elderly.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

Bepridil
Cisapride
Colchicine
Dronedarone
Fluconazole
Gepirone
Ketoconazole
Levoketoconazole
Mavacamten
Mesoridazine
Pimozide
Piperaquine
Posaconazole
Saquinavir
Sparfloxacin
Terfenadine
Thioridazine
Ziprasidone

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Abametapir
Adagrasib
Alfentanil
Alfuzosin
Amiodarone
Amisulpride
Amitriptyline
Anagrelide
Apomorphine
Aprepitant
Aripiprazole
Aripiprazole Lauroxil
Arsenic Trioxide
Asenapine
Astemizole
Atazanavir
Azithromycin
Bedaquiline
Boceprevir
Bosutinib
Buprenorphine
Buserelin
Carbamazepine
Ceritinib
Chloroquine
Chlorpromazine
Cilostazol
Ciprofloxacin
Citalopram
Clarithromycin
Clofazimine
Clomipramine
Clothiapine
Clozapine
Cobicistat
Conivaptan
Crizotinib
Cyclobenzaprine
Cyclosporine
Dabrafenib
Daridorexant
Dasatinib
Degarelix
Delamanid
Desipramine
Deslorelin
Dexmedetomidine
Dihydroergotamine
Disopyramide
Dofetilide
Dolasetron
Domperidone
Donepezil
Doxepin
Droperidol
Ebastine
Efavirenz
Elexacaftor
Encorafenib
Entrectinib
Enzalutamide
Ergotamine
Eribulin
Erythromycin
Escitalopram
Etrasimod
Everolimus
Famotidine
Fedratinib
Felbamate
Fentanyl
Fexinidazole
Fingolimod
Flecainide
Flibanserin
Fluoxetine
Fluticasone
Formoterol
Fosaprepitant
Foscarnet
Fosphenytoin
Fostemsavir
Galantamine
Gatifloxacin
Gemifloxacin
Glasdegib
Gonadorelin
Goserelin
Granisetron
Halofantrine
Haloperidol
Histrelin
Hydroquinidine
Hydroxychloroquine
Hydroxyzine
Ibutilide
Idelalisib
Iloperidone
Imipramine
Indinavir
Inotuzumab Ozogamicin
Itraconazole
Ivabradine
Ivacaftor
Ivosidenib
Lapatinib
Lefamulin
Lenvatinib
Leuprolide
Levofloxacin
Levomilnacipran
Lofexidine
Lopinavir
Lumacaftor
Lumefantrine
Lurbinectedin
Macimorelin
Mefloquine
Methadone
Methotrimeprazine
Metronidazole
Midazolam
Mifepristone
Mirtazapine
Mitotane
Mizolastine
Mobocertinib
Moricizine
Moxifloxacin
Nafarelin
Nefazodone
Nelfinavir
Nifedipine
Nilotinib
Norfloxacin
Octreotide
Ofloxacin
Olanzapine
Omaveloxolone
Ondansetron
Osilodrostat
Osimertinib
Oxaliplatin
Oxycodone
Ozanimod
Pacritinib
Paliperidone
Palovarotene
Panobinostat
Papaverine
Paroxetine
Pasireotide
Pazopanib
Pentamidine
Perphenazine
Phenobarbital
Phenytoin
Pimavanserin
Pipamperone
Pitolisant
Ponesimod
Pralsetinib
Primidone
Probucol
Procainamide
Prochlorperazine
Promethazine
Propafenone
Protriptyline
Quetiapine
Quinidine
Quinine
Quizartinib
Ranolazine
Relugolix
Rifampin
Risperidone
Ritonavir
Selpercatinib
Sertindole
Sertraline
Sevoflurane
Simvastatin
Siponimod
Sirolimus
Sodium Phosphate
Sodium Phosphate, Dibasic
Sodium Phosphate, Monobasic
Solifenacin
Sorafenib
Sotalol
St John's Wort
Sultopride
Sunitinib
Tacrolimus
Tamoxifen
Tegafur
Telaprevir
Telavancin
Telithromycin
Temsirolimus
Tetrabenazine
Tezacaftor
Tocilizumab
Tolterodine
Toremifene
Trazodone
Triclabendazole
Trimipramine
Triptorelin
Valbenazine
Vamorolone
Vandetanib
Vardenafil
Vemurafenib
Venlafaxine
Vilanterol
Vilazodone
Vinflunine
Voclosporin
Voriconazole
Vorinostat
Zolpidem
Zotepine
Zuclopenthixol
Zuranolone

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Amlodipine

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.

Grapefruit Juice

Proper use of ribociclib and letrozole

Medicines used to treat cancer are very strong and can have many side effects. Before taking this medicine, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.

Take this medicine exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.

This medicine comes with a patient information insert. Read and follow the instructions carefully. Ask your doctor if you have any questions.

It is important that you take both medicines at the same time each day, preferably in the morning.

Your doctor may also give you luteinizing hormone-releasing hormone medicine together with this medicine.

Swallow the tablet whole. Do not crush, break, or chew it. You may take this medicine with or without food.

Do not eat grapefruit or drink grapefruit juice while you are using this medicine.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

For oral dosage form (tablets):
- For metastatic breast cancer:
  - Adults—
    - Ribociclib: 600 milligrams (mg) (three 200 mg tablets) taken as a single dose, once a day for 21 days in a row, followed by 7 days without medicine. Your doctor may adjust your dose as needed and tolerated.
    - Letrozole: 2.5 milligrams (mg) once a day for 28 days.
  - Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

If you vomit after you take this medicine, do not take another dose the same day. Wait and take your next dose when you normally would.

Storage

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Store the medicine in its original package.

Precautions while using ribociclib and letrozole

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly. Blood tests may be needed to check for unwanted effects.

It is unlikely that a postmenopausal woman may become pregnant. But, using this medicine while you are pregnant can harm your unborn baby. If you are a woman who can bear children, your doctor may give you a pregnancy test before you start using this medicine to make sure you are not pregnant. Use an effective form of birth control to keep from getting pregnant during treatment and for at least 3 weeks after your last dose. If you think you have become pregnant while using the medicine, tell your doctor right away.

If you plan to have children, talk with your doctor before using this medicine. Some men and women using this medicine have become infertile (unable to have children).

Interstitial lung disease or pneumonitis can occur while using this medicine. This can be life-threatening and requires immediate medical attention. Check with your doctor right away if you have chest pain, cough, difficulty with breathing, fever or chills.

Serious skin reactions, including Stevens-Johnson Syndrome, toxic epidermal necrolysis, or drug reaction with eosinophilia and systemic symptoms (DRESS) can occur with this medicine. Check with your doctor right away if you have black, tarry stools, blistering, peeling, or loosening of the skin, chest pain, chills, cough, fever, painful or difficult urination, red skin lesions, sore throat, sores, ulcers, or white spots on the lips or in the mouth, swollen glands, unusual bleeding or bruising, or unusual tiredness or weakness with this medicine.

Contact your doctor right away if you have any changes to your heart rhythm. You might feel dizzy or faint, or you might have a fast, pounding, or uneven heartbeat. Make sure your doctor knows if you or anyone in your family has ever had a heart rhythm problem including QT prolongation.

Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a serious liver problem.

Ribociclib and letrozole combination can temporarily lower the number of some types of blood cells in your blood. Because of this, you may bleed or get infections more easily. To help with these problems, avoid being near people who are sick or have infections. Wash your hands often. Stay away from rough sports or other situations where you could be bruised, cut, or injured. Brush and floss your teeth gently. Be careful when using sharp objects, including razors and fingernail clippers.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (eg, St. John's wort) or vitamin supplements.

Side Effects of ribociclib and letrozole

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

Black, tarry stools
bladder pain
bleeding gums
bloating or swelling of the face, arms, hands, lower legs, or feet
bloody or cloudy urine
chest tightness
chills
cough
decrease in height
difficult, burning, or painful urination
fever
frequent urge to urinate
lower back or side pain
pain in the back, ribs, arms, or legs
pale skin
pinpoint red spots on the skin
sore throat
tingling of the hands or feet
trouble breathing
ulcers, sores, or white spots in the mouth
unusual bleeding or bruising
unusual tiredness or weakness
unusual weight gain or loss

Less common

Chest pain
confusion
dark urine
fainting
general feeling of discomfort or illness
irregular heartbeat
loss of appetite
mood or mental changes
muscle cramps in the hands, arms, feet, legs, or face
nausea
numbness and tingling around the mouth, fingertips, or feet
pain or tenderness in the upper stomach
pale stools
seizures
stomach cramps
thickening of bronchial secretions
tremor
vomiting
yellow eyes or skin

Incidence not known

Blistering, peeling, loosening of skin
diarrhea
joint or muscle pain
rash or itching skin
red irritated eyes
red skin lesions, often with a purple center
swollen glands

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common