Ribociclib and letrozole (Oral)
Medically reviewed by Drugs.com. Last updated on May 31, 2022.
Commonly used brand name(s)
In the U.S.
- Kisqali Femara Co-Pack
Available Dosage Forms:
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.
Ribociclib and letrozole 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 ribociclib and letrozole, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to ribociclib and letrozole 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.
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.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of ribociclib and letrozole combination in the elderly.
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 ribociclib and letrozole, 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 ribociclib and letrozole 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.
Using ribociclib and letrozole 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.
- Aripiprazole Lauroxil
- Arsenic Trioxide
- Inotuzumab Ozogamicin
- Sodium Phosphate
- Sodium Phosphate, Dibasic
- Sodium Phosphate, Monobasic
- St John's Wort
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 ribociclib and letrozole 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 ribociclib and letrozole, or give you special instructions about the use of food, alcohol, or tobacco.
- Grapefruit Juice
Other medical problems
The presence of other medical problems may affect the use of ribociclib and letrozole. Make sure you tell your doctor if you have any other medical problems, especially:
- Angina (severe chest pain), unstable or
- Congestive heart failure or
- Electrolyte imbalance (eg, high or low potassium, calcium, phosphorus, magnesium in the blood) or
- Heart attack, recent or
- Heart rhythm problems (eg, long QT syndrome, slow, fast, or irregular heartbeat)—Avoid use. May cause side effects to become worse.
- Infection or
- Neutropenia (low white blood cells)—May decrease your body's ability to fight infection.
- Kidney disease, severe or
- Liver disease, severe—Use with caution. The effects may be increased because of slower removal of the medicine from the body.
- Lung problems (eg, interstitial lung disease, pneumonitis)—Use with caution. May make these conditions worse.
Proper use of ribociclib and letrozole
Medicines used to treat cancer are very strong and can have many side effects. Before taking ribociclib and letrozole, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.
Take ribociclib and letrozole 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.
Ribociclib and letrozole 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 ribociclib and letrozole.
Swallow the tablet whole. Do not crush, break, or chew it. You may take ribociclib and letrozole with or without food.
Do not eat grapefruit or drink grapefruit juice while you are using ribociclib and letrozole.
The dose of ribociclib and letrozole 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 ribociclib and letrozole. 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:
- 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.
- For metastatic breast cancer:
If you miss a dose of ribociclib and letrozole, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
If you vomit after you take ribociclib and letrozole, do not take another dose the same day. Wait and take your next dose when you normally would.
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 ribociclib and letrozole 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 ribociclib and letrozole 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 ribociclib and letrozole 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 ribociclib and letrozole. Some men and women using ribociclib and letrozole have become infertile (unable to have children).
Interstitial lung disease or pneumonitis can occur while using ribociclib and letrozole. 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 ribociclib and letrozole. 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 ribociclib and letrozole.
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.
Ribociclib and letrozole side effects
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:
- 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
- decrease in height
- difficult, burning, or painful urination
- 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
- Chest pain
- dark urine
- 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
- numbness and tingling around the mouth, fingertips, or feet
- pain or tenderness in the upper stomach
- pale stools
- stomach cramps
- thickening of bronchial secretions
- yellow eyes or skin
Incidence not known
- Blistering, peeling, loosening of skin
- 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:
- Back pain
- dry skin
- lack or loss of strength
- loss or thinning of the hair
- mouth or throat pain
- swelling or inflammation of the mouth
- trouble sleeping
- dry eye
- increased tearing
- patchy loss of skin color
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
More about letrozole / ribociclib
- Side effects
- Drug interactions
- Dosage information
- During pregnancy
- Reviews (1)
- En español
- Drug class: antineoplastic combinations
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