Brukinsa Side Effects

Generic name: zanubrutinib

Medically reviewed by Philip Thornton, DipPharm. Last updated on Jun 11, 2025.

Note: This document provides detailed information about Brukinsa Side Effects associated with zanubrutinib. Some dosage forms listed on this page may not apply specifically to the brand name Brukinsa.

Applies to zanubrutinib: oral capsule.

Precautions

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.

Using this medicine while you are pregnant can harm your unborn baby. If you are a woman who can get pregnant, your doctor may give you a pregnancy test before you start using this medicine to make sure you are not pregnant. Women should use an effective form of birth control during treatment and for 1 week after the last dose. Men should use an effective form of birth control during treatment and for 1 week after the last dose to prevent pregnancy in a sexual partner. If you think a pregnancy has occurred with this medicine, tell your doctor right away.

This medicine may cause bleeding problems. Check with your doctor right away if you have bloody or black, tarry stools, red or dark brown urine, severe stomach pain, unusual bleeding, bruising, or weakness, or vomiting of blood or material that looks like coffee grounds.

Make sure any doctor or dentist who treats you knows that you are using this medicine. You may need to stop using this medicine several days before and after having surgery.

Zanubrutinib may lower the number of some types of blood cells in your body. 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.

Using this medicine may increase your risk of getting new cancers, including skin cancer. Avoid sun exposure. Use a sunscreen when you are outdoors. Avoid sunlamps and tanning beds.

This medicine may cause heart rhythm problems (eg, atrial flutter, atrial fibrillation). Check with your doctor right away if you have a fast or irregular heartbeat, trouble breathing, lightheadedness, dizziness, or fainting.

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 or vitamin supplements.

Serious side effects of Brukinsa

Along with its needed effects, zanubrutinib (the active ingredient contained in Brukinsa) 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 while taking zanubrutinib:

Other side effects of Brukinsa

Some side effects of zanubrutinib 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:

See also:

For healthcare professionals

Applies to zanubrutinib: oral capsule.

General adverse events

The most common adverse reactions were decreased neutrophil count, upper respiratory tract infection, decreased platelet count, hemorrhage/hematoma, rash, bruising, and musculoskeletal pain.^[Ref]

Cardiovascular

• Very common (10% or more): Hypertension (up to 19%)
• Common (1% to 10%): Atrial fibrillation/flutter, supraventricular arrhythmias, palpitation
• Uncommon (0.1% to 1%): Ventricular arrhythmias
• Frequency not reported: Cardiac arrhythmias, myocardial infarction, aortic dissection, cardiomegaly, congestive cardiac failure

Serious cardiac arrhythmias have occurred in patients treated with this drug. Atrial fibrillation and atrial flutter were reported in 3.7% of 1550 patients treated with this drug as monotherapy, including grade 3 or higher cases in 1.7% of patients. Grade 3 or higher ventricular arrhythmias were reported in 0.2% of patients.

Dermatologic

• Very common (10% or more): Rash (up to 37%), bruising (up to 30%), contusion (up to 18%), pruritus (up to 12.9%)
• Common (1% to 10%): Petechiae, purpura, ecchymosis
• Frequency not reported: General exfoliative dermatitis, allergic dermatitis

Rash included rash, maculopapular rash, erythema, erythematous rash, drug eruption, allergic dermatitis, atopic dermatitis, pruritic rash, dermatitis, photodermatoses, acneiform dermatitis, stasis dermatitis, vasculitic rash, eyelid rash, urticaria, skin toxicity, contact dermatitis, drug reaction with eosinophilia and systemic symptoms, photosensitivity reaction, papular rash, seborrheic dermatitis, toxic skin eruption, and related terms.

Bruising included all related terms containing bruise (including increased tendency to bruise), bruising, contusion (including postprocedural contusion), and ecchymosis.

Gastrointestinal

• Very common (10% or more): Diarrhea (up to 25%), nausea (up to 18%), constipation (up to 16.8%), abdominal pain (up to 14%), vomiting (up to 12.9%)
• Uncommon (0.1% to 1%): Gastrointestinal hemorrhage

Diarrhea included diarrhea and hemorrhagic diarrhea.

Abdominal pain included abdominal pain, upper abdominal pain, and abdominal discomfort.

Genitourinary

• Very common (10% or more): Urinary tract infection (up to 13%)
• Common (1% to 10%): Hematuria

Urinary tract infection included urinary tract infection, cystitis, Escherichia urinary tract infection, and pyelonephritis.

Hematologic

• Very common (10% or more): Decreased neutrophil count (up to 52%), lymphocytosis (up to 41%), hemorrhage/hematoma (up to 42%), decreased platelet count (up to 44%), decreased lymphocytes (up to 32%), decreased hemoglobin (up to 30%), neutropenia (up to 28%), decreased WBC count/leukopenia (up to 26%), increased leukocytes (up to 21%), thrombocytopenia (up to 16%), anemia (up to 14%)
• Common (1% to 10%): Major hemorrhage, febrile neutropenia
• Frequency not reported: Cytopenias

Grade 3 or 4 cytopenias (including neutropenia [22%], thrombocytopenia [8%], and anemia [7%] based on laboratory measurements) developed in patients treated with this drug as monotherapy. Grade 4 neutropenia and grade 4 thrombocytopenia occurred in 11% and 2.8% of patients, respectively.

Asymptomatic lymphocytosis (a known effect of Bruton's tyrosine kinase inhibition) has been reported.

Fatal and serious hemorrhage has occurred in patients with hematological malignancies treated with this drug as monotherapy. Grade 3 or higher hemorrhage (including intracranial and gastrointestinal hemorrhage, hematuria, and hemothorax) was reported in 3.6% of patients treated with this drug as monotherapy in clinical trials, with fatalities occurring in 0.3% of patients. Bleeding of any grade (excluding purpura and petechiae) occurred in 30% of patients. Bleeding has occurred in patients with and without concomitant antiplatelet or anticoagulation therapy.

Hemorrhage included all terms containing hematoma, hemorrhage, and hemorrhagic, and related terms indicative of bleeding including: epistaxis, hematuria, conjunctival hemorrhage, hematoma, rectal hemorrhage, periorbital hemorrhage, mouth hemorrhage, postprocedural hemorrhage, hemoptysis, skin hemorrhage, hemorrhoidal hemorrhage, ear hemorrhage, eye hemorrhage, hemorrhagic diathesis, periorbital hematoma, subdural hemorrhage, wound hemorrhage, gastric hemorrhage, lower gastrointestinal hemorrhage, spontaneous hematoma, traumatic hematoma, traumatic intracranial hemorrhage, tumor hemorrhage, retinal hemorrhage, hematochezia, hemorrhagic diarrhea, hemorrhage, melena, postprocedural hematoma, subdural hematoma, anal hemorrhage, hemorrhagic disorder, pericardial hemorrhage, postmenopausal hemorrhage, stoma site hemorrhage, subarachnoid hemorrhage, urinary tract hemorrhage, pulmonary hematoma, subcutaneous hematoma, gingival bleeding, and upper gastrointestinal hemorrhage.

Major hemorrhage (defined as grade 3 or higher hemorrhage or central nervous system hemorrhage of any grade) was reported in 5% of patients.

Hepatic

• Very common (10% or more): Increased ALT (up to 30%), increased bilirubin (up to 26%), increased AST (up to 12.1%)
• Uncommon (0.1% to 1%): Hepatitis B reactivation
• Frequency not reported: Drug-induced liver injury, hepatitis B

Metabolic

• Very common (10% or more): Increased glucose (up to 55%), increased blood uric acid (up to 31%), hypokalemia (up to 14%)
• Uncommon (0.1% to 1%): Tumor lysis syndrome

Musculoskeletal

• Very common (10% or more): Musculoskeletal pain (up to 45%), pain in extremity (up to 13.9%), arthralgia (up to 13%)
• Common (1% to 10%): Muscle spasms, back pain

Musculoskeletal pain included musculoskeletal pain, musculoskeletal discomfort, myalgia, back pain, arthralgia, arthritis, pain in extremity, bone pain, spinal pain, musculoskeletal chest pain, and neck pain.

Nervous system

• Very common (10% or more): Headache (up to 18%), dizziness (up to 13.9%)
• Frequency not reported: Cerebral hemorrhage, subdural hemorrhage, peripheral neuropathy, peripheral sensory neuropathy, cerebral infarction

Dizziness included dizziness and vertigo.

Oncologic

• Very common (10% or more): Second primary malignancy (up to 22%), nonmelanoma skin cancer (up to 13%)
• Common (1% to 10%): Basal cell carcinoma, squamous cell carcinoma of skin
• Frequency not reported: Plasma cell myeloma

Second primary malignancies (including nonskin carcinoma) have occurred in 13% of patients treated with this drug as monotherapy. The most frequent second primary malignancy was nonmelanoma skin cancer (7%); other second primary malignancies included malignant solid tumors (5%), melanoma (1.2%), and hematologic malignancies (0.5%).

Second primary malignancy included nonmelanoma skin cancer, malignant solid tumors (including lung, renal, genitourinary, breast, ovarian, rectal, bladder, prostate, pelvis, and ureter), chronic myeloid leukemia, and malignant melanoma.

Other

• Very common (10% or more): Fatigue (up to 31%), increased magnesium (up to 31%), decreased calcium (up to 27%), decreased phosphate (up to 27%), increased potassium (up to 24%), pyrexia (up to 16%), peripheral edema (up to 13.9%)
• Common (1% to 10%): Edema, asthenia, sepsis, localized infection
• Frequency not reported: Coronavirus disease 2019 (COVID-19)-related death, sepsis, road traffic accident

Fatal and serious infections (including bacterial, viral, or fungal infections) and opportunistic infections have occurred in patients with hematological malignancies treated with this drug as monotherapy. Grade 3 or higher infections occurred in 24% of patients (most commonly pneumonia [11%]), with fatal infections occurring in 2.9% of patients. Infections due to hepatitis B virus reactivation have occurred.

Fatigue included asthenia, fatigue, and lethargy.

Renal

• Very common (10% or more): Increased creatinine (up to 34%)
• Frequency not reported: Renal insufficiency

Respiratory

• Very common (10% or more): Upper respiratory tract infection (up to 44%), pneumonia (up to 20%), cough (up to 19%), epistaxis (up to 15.8%), dyspnea (up to 14.9%), COVID-19 (up to 14%), nasopharyngitis (up to 10.9%)
• Common (1% to 10%): Influenza, lower respiratory tract infection, bronchitis
• Frequency not reported: Respiratory tract infection, pleural effusion, lung infection

Upper respiratory tract infection included upper respiratory tract infection, viral upper respiratory tract infection, laryngitis, nasopharyngitis, sinusitis, rhinitis, pharyngitis, rhinovirus infection, upper respiratory tract congestion, tonsillitis, upper respiratory tract inflammation, and related terms.

Pneumonia included pneumonia, fungal pneumonia, cryptococcal pneumonia, streptococcal pneumonia, atypical pneumonia, lung infection, lower respiratory tract infection, bacterial lower respiratory tract infection, viral lower respiratory tract infection, lung infiltration, aspiration pneumonia, viral pneumonia, COVID-19 pneumonia, bronchopulmonary aspergillosis, organizing pneumonia, and related terms (including specific types of infection).

Cough included cough and productive cough.

COVID-19 included COVID-19, COVID-19 pneumonia, post-acute COVID-19 syndrome, and positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test.

Frequently asked questions

• What are the names of the BTK inhibitors?

Further information

Brukinsa side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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