Acalabrutinib: what it treats, how to take it, side effects
Last updated September 6, 2026.
**Acalabrutinib (Calquence) is a prescription cancer medicine called a Bruton tyrosine kinase (BTK) inhibitor.** It blocks signals that help certain cancerous white blood cells grow and survive. Serious bleeding is a key safety concern, so report unusual bleeding immediately, especially if you take a blood thinner.
What does it treat?
Your oncologist may prescribe acalabrutinib for chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL), or mantle cell lymphoma (MCL). For MCL, it is used alone after at least one previous treatment, or with bendamustine and rituximab for previously untreated adults who cannot receive a transplant using their own stem cells. For CLL or SLL, treatment can include acalabrutinib alone or, in previously untreated disease, with obinutuzumab or venetoclax. These are separate medicines, not a combination pill.
How do you take it?
Acalabrutinib comes as 100 mg tablets and capsules; do not switch forms yourself. The usual adult dose is 100 mg about every 12 hours, totaling 200 mg daily, with or without food. Stay within your prescribed daily dose; the label permits higher dosing only for a specific interaction managed by your oncologist. Swallow whole with water: do not cut, crush, chew, or dissolve tablets, or open, break, or chew capsules. Take a missed dose within 3 hours of its scheduled time; after that, skip it and never double up. Stop taking it and contact your care team immediately for fever, significant bleeding, or a new irregular heartbeat.
Side effects to know
- Common: You may experience headache, diarrhea, muscle or joint pain, tiredness, nausea, bruising, or respiratory infections.
- Serious: Stop taking acalabrutinib and get urgent medical help for black stools, vomiting blood, fever or chills, fainting, or a racing or irregular heartbeat. Yellow skin or eyes, dark urine, or upper right abdominal pain need prompt assessment for liver injury; treatment also requires blood counts and liver tests, and sun protection because additional cancers, including skin cancer, can occur.
Who should not take it?
Before treatment, tell your oncologist about any drug allergy, bleeding disorder, infection, hepatitis B, heart rhythm problem, liver disease, or planned surgery or dental procedure. Avoid use with severe liver impairment. Review all prescriptions, supplements, and nonprescription medicines, especially blood thinners and medicines that affect CYP3A, which changes how your body processes acalabrutinib. It can harm your unborn baby; pregnancy testing and effective contraception are needed if you can become pregnant. Do not breastfeed during treatment. The label gives no specific alcohol limit, so discuss drinking with your oncology team.
When is it an emergency?
Call 911 for collapse, breathing trouble, swelling of your tongue or throat, uncontrolled bleeding, or sudden weakness, confusion, or trouble speaking. Vomiting blood or passing black stools needs emergency evaluation. Fever or chills need immediate contact with your oncology team and same-day assessment. If you also take venetoclax, markedly reduced urination with muscle cramps, vomiting, or confusion needs emergency evaluation for tumor lysis syndrome. For overdose, call Poison Control at 1-800-222-1222 immediately, even without symptoms; there is no reliable symptom pattern that rules out harm.
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Common questions
What is the maximum daily dose?
Your usual dose is 100 mg every 12 hours, or 200 mg daily. This is not an absolute label maximum: if an unavoidable strong CYP3A inducer is prescribed, your oncologist may use 200 mg every 12 hours, totaling 400 mg daily. Never make this adjustment yourself.
Can I drink alcohol?
The FDA label does not set an alcohol allowance. Ask your oncology team before drinking. Your liver health, symptoms, and other cancer medicines determine the advice for you.
What if I am pregnant or breastfeeding?
Contact your oncologist immediately if you become pregnant. Use effective contraception during treatment and for at least 1 week after your final dose. Do not breastfeed during treatment or for at least 2 weeks afterward.
Do I need food, and can I have grapefruit?
You can take your dose with or without food. Swallow it whole with water. Check with your pharmacist before eating grapefruit or drinking grapefruit juice.
What are the signs of an overdose?
There is no established set of symptoms you can use to identify an overdose at home. Call Poison Control at 1-800-222-1222 after an extra dose rather than waiting for symptoms. Call 911 for collapse, seizures, or breathing trouble.
Can I take heartburn medicines with it?
The answer depends on your formulation. With capsules, avoid proton pump inhibitors such as omeprazole, take acalabrutinib 2 hours before an H2 blocker such as famotidine, and separate antacids by at least 2 hours. Tablets do not have these stomach acid restrictions. Have your pharmacist check your bottle and full medication list.