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

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

• arm, leg, back pain
• Constipation
• decreased appetite
• Diarrhea
• dizziness
• headache
• mouth sores
• nausea
• skin rash or redness
• stomach pain or cramps
• tingling, pain, or numbness in the hands, legs, or feet
• tiredness
• trouble sleeping
• unsteadiness, causing falls
• vomiting
• watery eyes

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:

• memory loss
• new cancers (skin or other)
• rapid, pounding heartbeat
• 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)
• symptoms of irregular heartbeat (e.g., chest pain, dizziness, confusion, rapid, pounding heartbeat, shortness of breath)
• symptoms of Low Blood Pressure (e.g., fainting, dizziness, lightheadedness, blurred vision, nausea)
• symptoms of pneumonia (e.g., cough with or without mucus, fever, chills, difficult and painful breathing, shortness of breath when climbing stairs)

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

• signs of bleeding in the stomach (e.g., bloody, black, or tarry stools, spitting up of blood, vomiting blood or material that looks like coffee grounds)

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 Calquence (Acalabrutinib).

Each size 1 hard gelatin capsule, with a yellow body and blue cap, marked in black ink "ACA 100 mg", contains 100 mg of Calquence (Acalabrutinib). Nonmedicinal ingredients: ammonium hydroxide, black iron oxide, colloidal silicon dioxide, FD&C Blue 2 (Indigotine/Indigo carmine), gelatin, magnesium stearate, microcrystalline cellulose, partially pregelantinized starch (maize), propylene glycol, shellac, sodium starch glycolate (Type A), titanium dioxide, and yellow iron oxide.

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

There may be an interaction between Calquence (Acalabrutinib) and any of the following:

• antacids (e.g., aluminum hydroxide, calcium carbonate, magnesium hydroxide)
• anticancer medications (e.g., Cladribine, Irinotecan)
• anticoagulants (e.g. Apixaban, dabigatran, Edoxaban, Rivaroxaban, Warfarin)
• Apalutamide
• Aripiprazole
• "azole" antifungals (e.g., itraconazole, ketoconazole, Voriconazole)
• Baricitinib
• BCG
• Bosentan
• calcium channel blockers (e.g., Amlodipine, Diltiazem, Nifedipine, Verapamil)
• Carbamazepine
• Clozapine
• Cobicistat
• conivaptan
• Deferasirox
• Denosumab
• Dronedarone
• echinacea
• Enzalutamide
• Fingolimod
• grapefruit juice
• H2 antagonists (e.g., Famotidine, Ranitidine)
• HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., efavirenz, etravirine, nevirapine)
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• Leflunomide
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• Mesalamine
• mifepristone
• Mitotane
• Modafinil
• Natalizumab
• Ocrelizumab
• Phenobarbital
• Phenytoin
• Pimecrolimus
• primidone
• protein kinase inhibitors (e.g., Crizotinib, Dabrafenib, Idelalisib, imatinib, Palbociclib,)
• proton pump inhibitors (e.g., Lansoprazole, Omeprazole)
• rifabutin
• rifampin
• Roflumilast
• St. John's wort
• Sarilumab
• Sertraline
• Stiripentol
• Tocilizumab
• Tofacitinib
• 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 Calquence (Acalabrutinib). 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 Calquence (Acalabrutinib).

Anemia: Calquence (Acalabrutinib) 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: Calquence (Acalabrutinib) 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.

Fatigue/reduced alertness: Calquence (Acalabrutinib) may cause fatigue 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 Calquence (Acalabrutinib) affects you.

Heart rhythm: Calquence (Acalabrutinib) can cause an irregular heart rhythm called atrial fibrillation. If you experience symptoms of lightheadedness, dizziness, shortness of breath, or a rapid, pounding heartbeat, talk to your doctor as soon as possible.

Hepatitis B reactivation: People who have hepatitis B infection that is dormant may experience the infection returning, as a result of a weakened immune system. If you have a history of hepatitis B infection, discuss with your doctor how Calquence (Acalabrutinib) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this mediation, and whether any special monitoring is needed.

If you experience symptoms of worsening liver function, 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.

Infection: Calquence (Acalabrutinib) can reduce the number of cells that fight infection in the body (white blood cells). This may lead to serious and sometimes deadly 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. If possible, avoid contact with people with contagious infections. 

Other cancers: Rarely, people who take Calquence (Acalabrutinib) experience other types of cancer. Most commonly, this is Skin Cancer, but other non-blood cancers may occur. Talk to your doctor if you have concerns.

Progressive multifocal leukoencephalopathy (PML): There have been reports of PML after using Calquence (Acalabrutinib). PML is a rare disorder that causes nerve damage in the brain. If you experience memory loss, vision changes, trouble thinking, personality changes, or difficulty walking, contact your doctor immediately.

Surgery: Tell all the health care professionals involved in your care that you are taking Calquence (Acalabrutinib). Some doctors may suggest you stop taking Calquence (Acalabrutinib) for a short period of time before or after surgery.

Pregnancy: Calquence (Acalabrutinib) should not be used during pregnancy. If you become pregnant while taking Calquence (Acalabrutinib), contact your doctor immediately.

Breast-feeding: It is not known if Calquence (Acalabrutinib) passes into breast milk. If you are a breast-feeding mother and are taking Calquence (Acalabrutinib), it may affect your baby. Breast-feeding should be avoided until at least 2 weeks after taking the last dose of medication.

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