Imbruvica (Ibrutinib) — NZ Medication Guide | KiwiMeds
✅ Reviewed by Ramon Wong, BPharm, Registered Pharmacist (New Zealand) | May 2026 — This information is for educational purposes only and is not a substitute for personalised advice from your doctor or pharmacist. Always seek professional guidance before making changes to your medications.
What is Imbruvica (ibrutinib)?
Imbruvica (generic name: ibrutinib) is an oral targeted cancer medicine used to treat certain blood cancers. It belongs to a class of medicines called Bruton’s tyrosine kinase (BTK) inhibitors. Ibrutinib works by blocking a specific protein that cancer cells need to grow and survive. It is taken as a capsule at home — meaning many people can be treated without needing regular hospital infusions.
What is it used for? (NZ context)
In New Zealand, ibrutinib (Imbruvica) is funded by Pharmac for adults with chronic lymphocytic leukaemia (CLL). From 1 May 2026:
● Ibrutinib + venetoclax — funded as a first-line (initial) combination treatment for CLL
● Ibrutinib alone — funded with widened access as a second-line treatment for CLL (for people who have already received treatment)
People who have been self-funding ibrutinib may be eligible to switch to the funded combination treatment. Around 110 people per year are expected to benefit from the combination, and around 30 people per year from the widened second-line ibrutinib access. See the Pharmac announcement. Speak with your haematologist to check your eligibility.
How does it work?
Ibrutinib targets a protein called Bruton’s tyrosine kinase (BTK) — an enzyme that acts as a signal inside B-cells (the type of white blood cell affected in CLL). Normally, BTK tells B-cells to grow, survive, and move around the body. In CLL, the cancer cells rely heavily on BTK signalling to keep multiplying. Ibrutinib permanently blocks BTK, cutting off this growth signal and causing CLL cells to stop dividing and eventually die. Because ibrutinib specifically targets BTK, it is more targeted than traditional chemotherapy. When used with venetoclax (which targets a different survival protein, BCL-2), the two medicines attack CLL cells through complementary pathways, often leading to deeper and longer remissions.
How to take it
Ibrutinib (Imbruvica) is taken as capsules by mouth, once daily at approximately the same time each day. The usual dose for CLL is 420 mg (three 140 mg capsules) once daily.
Important instructions:
- Swallow capsules whole with a glass of water — do not open, break, or chew them
- Can be taken with or without food
- Take at roughly the same time each day
- If you miss a dose and remember the same day, take it as soon as possible. If the next day, skip the missed dose and continue your regular schedule — never double up
- Store at room temperature, away from moisture and heat
Common side effects
Common side effects of ibrutinib include:
- Diarrhoea (very common, especially in the first few months)
- Fatigue (tiredness)
- Nausea
- Muscle and joint pain
- Bruising more easily than usual
- Low white blood cell counts (increased infection risk)
- Rash
- Upper respiratory infections (colds, sinusitis)
- High blood pressure
- Swelling of ankles and feet (fluid retention)
Serious side effects to watch for
Contact your doctor or seek urgent medical care if you experience:
- Bleeding: unusual bruising, prolonged bleeding from cuts, blood in urine or stools, coughing up blood — ibrutinib can affect platelet function and increase bleeding risk
- Irregular heartbeat or palpitations — ibrutinib can cause atrial fibrillation (AF), which increases stroke risk
- Signs of infection: fever, chills, shaking, feeling very unwell — your immune system is weaker on ibrutinib
- Chest pain or shortness of breath — may indicate heart problems
- Severe diarrhoea — if persistent or with blood
- Hypertension (high blood pressure) — have your BP checked regularly
Important drug interactions
Ibrutinib is metabolised by the CYP3A4 enzyme, leading to many important interactions:
Avoid or use with caution (increase ibrutinib levels):
- Antifungals: fluconazole, itraconazole, posaconazole, voriconazole
- Antibiotics: clarithromycin, erythromycin
- HIV medicines: ritonavir, cobicistat
- Grapefruit, grapefruit juice, Seville (bitter) oranges
Reduce ibrutinib effectiveness — avoid:
- Rifampicin, carbamazepine, phenytoin, St John’s Wort
Increased bleeding risk — discuss with specialist:
- Blood thinners: warfarin, heparin
- Antiplatelet medicines: aspirin, clopidogrel
- NSAIDs (ibuprofen, naproxen)
Things to avoid while taking it
- Grapefruit and grapefruit juice — increases ibrutinib levels
- Seville/bitter oranges — same effect as grapefruit
- Live vaccines — not recommended during ibrutinib treatment
- Blood thinners and NSAIDs without specialist advice — increases bleeding risk significantly
- Starting new medicines without checking — many drugs interact with ibrutinib
NZ-specific information
Brand name in NZ: Imbruvica
Funded: Yes — from 1 May 2026 for CLL (ibrutinib + venetoclax as first-line; ibrutinib alone as widened second-line access)
Available as: Capsules (140 mg)
Special Authority: Required — your haematologist will apply on your behalf
Prescription type: Hospital specialist prescription
CLL is a slow-growing blood cancer. The combination of ibrutinib and venetoclax can help many people achieve deep remissions, allowing them to go longer without needing further treatment. Pharmac estimates around 3,700 infusion hours will be saved annually because ibrutinib is an oral medicine, reducing hospital visits compared to IV chemotherapy.
Frequently asked questions
Is ibrutinib a chemotherapy?
No — ibrutinib is a targeted therapy, not a traditional chemotherapy. It specifically targets the BTK protein in cancer cells. It can still cause side effects, but it generally has a different profile to conventional chemo.
How long do I take ibrutinib?
When combined with venetoclax for CLL, ibrutinib is taken for a fixed period (your specialist will tell you). When used alone as ongoing therapy, treatment continues until the cancer stops responding or side effects become unmanageable.
Can I drive and work while on ibrutinib?
Yes, most people continue normal daily activities. Fatigue can affect some people, especially at first. Avoid activities that risk significant injury due to the increased bruising/bleeding tendency.
What if I need surgery?
Tell your surgeon and anaesthetist you are on ibrutinib. It may need to be paused before and after surgery due to bleeding risk.
Related medications
- Venetoclax (Venclexta) — combined with ibrutinib for CLL
- Obinutuzumab (Gazyvaro) — alternative combination partner for venetoclax in CLL