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 Verzenio (Abemaciclib). If you are concerned about side effects, discuss the risks and benefits of Verzenio (Abemaciclib) with your doctor.

The following side effects have been reported by at least 1% of people taking Verzenio (Abemaciclib). 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.

• changed sense of taste
• decreased appetite
• dizziness
• Dry Mouth
• eye pain
• fatigue
• feeling faint
• fractures
• hair loss or thinning
• headache
• increased tear production
• itchiness
• mouth sores
• muscle weakness
• nausea
• skin rash or inflammation
• stomach pain
• trouble swallowing
• vomiting

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:

• blurred vision
• broken bones or fractures
• Diarrhea (liquid or loose stools)
• low levels of calcium in the blood (e.g., muscle cramps in the back and legs, dry skin, confusion, memory loss)
• pain, swelling, numbness, tingling, redness and flaking or blistering palms or soles of feet
• 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 infection (symptoms may include Fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness)
• signs of kidney problems (e.g., change in the amount or colour of urine, increased urination at night, blood in the urine, swelling in the feet or legs)
• signs of low potassium levels in the blood (e.g., weakness, fatigue, muscle cramps, irregular heartbeat)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• signs of lung problems (e.g., shortness of breath, painful breathing, tiredness, wheezing, fever or cough)
• symptoms of irregular heart beat (e.g., chest pain, dizziness, rapid, pounding heartbeat, shortness of breath)

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

• signs of a blood clot in the arm or leg (tenderness, pain, swelling, warmth, or redness in the arm or leg) or lungs (difficulty breathing, sharp chest pain that is worst when breathing in, coughing, coughing up blood, sweating, or passing out)
• signs of a Heart Attack (e.g., chest pain or pressure, pain extending through shoulder and arm, nausea and vomiting, sweating)
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of Stroke (e.g., sudden or severe headache; sudden loss of coordination; vision changes; sudden slurring of speech; or unexplained weakness, numbness, or pain in arm or leg)
• symptoms of sepsis (blood infection; e.g., high fever, fast heart rate, rapid breathing)

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 Verzenio (Abemaciclib).

50 mg
Each modified oval, beige tablet with "Lilly" debossed on one side and "50" on the other side, contains 50 mg of Verzenio (Abemaciclib). Nonmedicinal ingredients: croscarmellose sodium, lactose monohydrate, microcrystalline cellulose 101, microcrystalline cellulose 102, silicon dioxide, and sodium stearyl fumarate; film coating: iron oxide red, iron oxide yellow, polyethylene glycol, polyvinyl alcohol, talc, and titanium dioxide.

100 mg
Each modified oval, white-to-practically-white tablet with "Lilly" debossed on one side and "100" on the other side, contains 100 mg of Verzenio (Abemaciclib). Nonmedicinal ingredients: croscarmellose sodium, lactose monohydrate, microcrystalline cellulose 101, microcrystalline cellulose 102, silicon dioxide, and sodium stearyl fumarate; film coating: polyethylene glycol, polyvinyl alcohol, talc, and titanium dioxide.

150 mg
Each modified oval, yellow tablet with "Lilly" debossed on one side and "150" on the other side, contains 150 mg of Verzenio (Abemaciclib). Nonmedicinal ingredients: croscarmellose sodium, lactose monohydrate, microcrystalline cellulose 101, microcrystalline cellulose 102, silicon dioxide, and sodium stearyl fumarate; film coating: iron oxide yellow, polyethylene glycol, polyvinyl alcohol, talc, and titanium dioxide.

200 mg
Each modified oval, beige tablet with "Lilly" debossed on one side and "200" on the other side, contains 200 mg of Verzenio (Abemaciclib). Nonmedicinal ingredients: croscarmellose sodium, lactose monohydrate, microcrystalline cellulose 101, microcrystalline cellulose 102, silicon dioxide, and sodium stearyl fumarate; film coating: iron oxide red, iron oxide yellow, polyethylene glycol, polyvinyl alcohol, talc, and titanium dioxide.

Do not take Verzenio (Abemaciclib) if you are allergic to Verzenio (Abemaciclib) or any ingredients of the medication.

There may be an interaction between Verzenio (Abemaciclib) and any of the following:

• Apalutamide
• Aprepitant
• "azole" antifungals (e.g., itraconazole, ketoconazole, Voriconazole)
• BCG
• Baricitinib
• Bosentan
• calcium channel blockers (e.g., Amlodipine, Diltiazem, Nifedipine, Verapamil)
• Cladribine
• Clozapine
• Cobicistat
• conivaptan
• Cyclosporine
• Deferasirox
• Deferiprone
• Denosumab
• Digoxin
• Dronedarone
• echinacea
• Enzalutamide
• Fingolimod
• grapefruit juice
• HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., delavirdine, efavirenz, etravirine, nevirapine)
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• Leflunomide
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• Mesalamine
• Metformin
• mifepristone
• Mitotane
• Modafinil
• Natalizumab
• Nivolumab
• Pimecrolimus
• protein kinase inhibitors (e.g., Crizotinib, imatinib, Palbociclib)
• rifabutin
• rifampin
• Roflumilast
• St. John's wort
• seizure medications (e.g., Carbamazepine, Phenobarbital, Phenytoin, primidone)
• siltuximab
• Tacrolimus
• Tocilizumab
• Tofacitinib
• Trastuzumab
• vaccines

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 Verzenio (Abemaciclib). 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.

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 Verzenio (Abemaciclib).

Blood Clots: Verzenio (Abemaciclib) 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 Verzenio (Abemaciclib) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Verzenio (Abemaciclib), and whether any special monitoring is needed.
If you experience symptoms such as sharp pain and swelling in the leg, difficulty breathing, or sudden chest pain, contact your doctor immediately.

Diarrhea: Diarrhea is a common side effect of Verzenio (Abemaciclib). It is most likely to occur in the first few months that you are taking Verzenio (Abemaciclib). Severe diarrhea that is not treated may lead to dehydration and severe complications affecting blood pressure, kidneys, and other organs. If you experience watery or runny bowel movements while you are taking Verzenio (Abemaciclib), contact your doctor as soon as possible. If your doctor has recommended an antidiarrheal medication (e.g., Loperamide), you should start taking it, as well as increase the amount of fluids you are drinking.

Drowsiness/dizziness: Verzenio (Abemaciclib) 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 Verzenio (Abemaciclib) affects you.

Infection: Like other medications to treat cancer, Verzenio (Abemaciclib) 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 grapefruit juice affect how Verzenio (Abemaciclib) is removed from the body, and may cause the medication to build up in the body. This can lead to potentially harmful side effects. Avoid these foods taking Verzenio (Abemaciclib) for treatment.

Liver function: Liver disease or reduced liver function may cause Verzenio (Abemaciclib) to build up in the body, causing side effects.

Verzenio (Abemaciclib) can also reduce liver function. If you have liver problems, discuss with your doctor how Verzenio (Abemaciclib) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Verzenio (Abemaciclib), and whether any special monitoring is needed. Your doctor will order routine blood tests to test your liver function while you are taking Verzenio (Abemaciclib).

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.

Pregnancy: Verzenio (Abemaciclib) should not be used during pregnancy. If you become pregnant while taking Verzenio (Abemaciclib), contact your doctor immediately. Women who may become pregnant should use effective birth control while taking Verzenio (Abemaciclib) and for at least 3 weeks after taking the last dose.

Breast-feeding: It is not known if Verzenio (Abemaciclib) passes into breast milk. If you are a breast-feeding mother and are taking Verzenio (Abemaciclib), it may affect your baby. Women taking Verzenio (Abemaciclib) should avoid breast-feeding while taking Verzenio (Abemaciclib) and for at least 3 weeks after taking the last dose.

Children: The safety and effectiveness of using Verzenio (Abemaciclib) have not been established for children.

Seniors: People over the age of 65 may be more likely to experience side effects from taking Verzenio (Abemaciclib).