Venclexta

Venclexta (Venetoclax)

What is Venclexta (Venetoclax)?

Venclexta is one of a group of cancer-fighting medications that belongs to a group of medications called antineoplastics. Venclexta may be prescribed to you by your doctor if you have cancer. It is only available with a prescription and is only ever prescribed to adults with specific cancers. These include acute myeloid leukemia (AML), small lymphocytic lymphoma (SLL), and chronic lymphocytic leukemia (CLL).

How does it work?

Venclexta can be used alone or with other medications and is usually prescribed to patients with AML, SLL, and CLL.

Patients with AML have unusual myeloid cell growth in the bone marrow. These build up in the body and take the place of healthy cells. Venclexta is prescribed to patients who have been newly diagnosed with AML. It is prescribed along with other cancer medications, such as azacitidine (Onureg, Vidaza), decitabine (Dacogen), and cytarabine.

CLL is a blood cancer. It results in the production of too many white blood cells that last too long. For those with SLL, cancer cells are found in the lymph nodes. Venclexta is suitable for AML sufferers aged 75 or over. Or it can be prescribed to any adults for whom chemotherapy is unsuitable. Unlike patients with AML, Venclexta can be prescribed to adults of any age with SLL and CLL.

It works by stopping one of the body’s proteins from helping cancer cells to thrive. Venclexta helps to reduce the number of cancer cells in the body.

Dosage

For most CLL patients prescribed Venclexta, the dose they begin with will be 20 mg made up of two 10 mg tablets. This is taken orally, once a day for seven days. The dose is then increased on a weekly basis until it reaches the optimal treatment dose of 400 mg. Each week, before the next increase in dosage, your doctor should carry out blood tests.

As for AML patients, their first day taking Venclexta usually begins with 100 mg which is taken orally, before it is increased on the second day to 200 mg, and then taken up to 400 mg on the third day. Whether the daily dose remains 400 mg or increases to 600 mg on the fourth day will depend on the other medication the patient is taking.

In addition to other medications, there are various factors that can impact the dosage a patient’s doctor recommends for them. A patient’s weight or other medical conditions can also have an impact. So, if you find that the doses listed here are different to what your doctor has prescribed, you should follow their recommendations and not change the dose without consulting them.

Gradually increasing the dosage means patients have a lower risk of suffering significant side effects. Patients should drink at least 1.75 litres of water each day (7 glasses) for even less chance that they will suffer severe side effects.

Overdose

Venclexta does not have a specific antidote. Any patients who have overdosed on it should be monitored and given appropriate supportive treatment. As the dosage is increased, patients should also be observed for symptoms of toxicities. It should be noted that dialysis will not necessarily filter out much of the Venclexta due to high protein binding and significant distribution levels. If you have severe symptoms after an overdose of Venclexta you should seek out the nearest emergency services.

Contraindications

Use of strong CYP3A inhibitors when starting to use Venclexta, and throughout the ramp-up period, is contraindicated for patients with SLL or CLL. This is because of the heightened risk of tumor lysis syndrome.

Side Effects

Not everyone who uses Venclexta will experience the side effects listed below. If you are concerned about the possible side effects, you should discuss them, along with the benefits of Venclexta with your doctor before you take it.

At least 1% of the patients taking Venclexta have reported the following side effects. In many cases, these can be managed, or may naturally dissipate over time. Your pharmacist may be able to provide guidance for managing the side effects of Venclexta, but you should speak with your doctor if they are severe or become a nuisance.

• constipation
• cough
• decreased appetite
• diarrhea
• dizziness
• fever
• headache
• itching
• mouth sores
• muscle and joint pain
• nausea
• rash
• shortness of breath
• stomach pain
• tiredness
• vomiting
• weakness
• weight loss

While the following side effects don’t often occur, they can cause significant issues if you do not follow up with your doctor or medical professional.

• low blood pressure symptoms
  • dizziness or fainting when getting up from being laid down or seated
  • blurred vision
  • fatigue
• signs of anemia (low red blood cells)
  • dizziness
  • pale skin
  • tiredness
  • weakness
  • shortness of breath
• signs of clotting problems
  • unusual nosebleeds
  • bruising
  • blood in urine
  • coughing blood
  • bleeding gums
  • cuts that don’t stop bleeding
• signs of infection
  • fever
  • chills
  • severe diarrhea
  • shortness of breath
  • prolonged dizziness
  • headache
  • stiff neck
  • weight loss
  • or listlessness
• signs of sepsis (blood infection)
  • fever
  • dizziness
  • chills
  • extreme body temperature
  • low blood pressure
  • rapid heartbeat
  • rapid, shallow breathing
• swollen ankles or feet
• liver problems symptoms
  • swelling
  • pain
  • tenderness or lump in the upper abdominal area
  • yellowing of eyes or skin
  • itchy skin
• pneumonia symptoms
  • chills
  • coughing with or without mucus
  • fever
  • shortness of breath
• symptoms of too much potassium in the body
  • muscle fatigue
  • weakness
  • difficulty moving
  • abnormal heart rhythms
  • nausea
• urinary tract infection symptoms
  • pain when urinating
  • urinating more often than usual
  • low back or flank pain
• upper respiratory tract infection symptoms
  • nasal congestion
  • cough
  • runny nose
  • sinusitis

If any of the following appear, immediately stop using Venclexta and find medical help.

• chest pain
• irregular heartbeat
• serious allergic reaction symptoms
  • abdominal cramps
  • difficulty breathing
  • nausea and vomiting
  • swelling of the face and throat
• symptoms of a serious blood infection, like sepsis
  • fever
  • chills
  • dizziness
  • high or low body temperature
  • weakness
  • rapid breathing
  • rapid heartbeat
• tumor lysis syndrome symptoms
  • producing less urine
  • cloudy urine
  • kidney problems
  • muscle spasms
  • nausea
  • shortness of breath

Other side effects may occur, you should see your doctor if you develop any symptoms that worry you whilst on Venclexta.

It should be noted that seniors over the age of 65 are more likely to experience side effects after taking Venclexta.

Warnings & Precautions

Do not take this medication if you:

• are allergic to Venclexta or any of its ingredients
• are taking any of the following:
  • ketoconazole
  • itraconazole
  • voriconazole
  • posaconazole
  • clarithromycin
  • erythromycin
  • protease inhibitors such as indinavir, lopinavir, ritonavir

Before starting treatment with Venclexta, let your doctor know of any allergies or medical issues you have. Make sure they are aware of all the other medication you are taking. Let them know if you are pregnant, breastfeeding, or if there are any other health-related issues your doctor needs to know about, as these may have an impact on how you should take Venclexta.

Bleeding

Venclexta has been known to cause severe bleeding when used with other medications in the treatment of AML. It can be life-threatening, so regular nosebleeds, unexplained bruising, or unusually dark stools, should be reported to your doctor.

Fertility

When used by men, Venclexta can lower or stop sperm production, so if you are planning on fathering a child, you should speak with your doctor before taking Venclexta.

Infection

The white blood cells, cells that battle infections in the body, are reduced by taking Venclexta. So, whilst on Venclexta, try to avoid picking up infections. Your doctor should carry out regular blood tests to check on the types of blood cells in your blood. If you do notice any infection symptoms, you should let your doctor know as soon as possible. The signs include:

• fever or chills
• severe diarrhea
• shortness of breath
• prolonged dizziness
• headache
• stiff neck
• weight loss
• listlessness

Kidneys

You should discuss with your doctor how Venclexta might impact your medical condition if you have kidney disease or compromised kidney functions. Your condition might impact your prescribed dose of Venclexta and may necessitate special monitoring.

Liver

If you have reduced liver function you need to discuss it with your doctor before taking Venclexta. It may affect the dose your doctor prescribes or require additional monitoring.

Cancers

The risk of developing skin cancer may be increased by using Venclexta. Look out for any unusual growths or changes to growths on your skin and immediately report them to your doctor.

Tumor Lysis Syndrome

Venclexta causes a lot of cancer cells to be killed at the outset of treatment. As a result, the body can be flooded with waste products and may not be able to flush it all out. This is called tumor lysis syndrome and it can lead to:

• nausea
• shortness of breath
• cloudy urine
• joint pain

Gradually increasing patients’ dose of Venclexta is meant to help them avoid developing the above symptoms, but drinking plenty of water can help to quell them. There are medications that can support your body as it gets rid of waste. Your doctor can prescribe something appropriate, but be sure to understand how to take the medication and let your doctor know if you experience any of the above symptoms.

Vaccines

If you are using Venclexta you should not have any vaccines, including yellow fever, BCG, cholera, typhoid, varicella, meningococcal, and diphtheria. Patients should either make sure they have their vaccinations before taking Venclexta or leave them until after their Venclexta treatment is over.

Drug Interactions

Venclexta may interact with any of the following:

• 5-ASA medications, such as:
  • mesalamine
  • olsalazine
  • sulfasalazine
• antiarrhythmics
  • amiodarone
  • dipyridamole
  • dronedarone
  • propafenone
  • quinidine
• apalutamide
• aprepitant
• azole antifungals, such as:
  • itraconazole
  • ketoconazole
  • voriconazole
• bacillus Calmette-Guérin (BCG)
• baricitinib
• birth control pills
• bosentan
• calcium channel blockers, such as:
  • amlodipine
  • diltiazem
  • nifedipine
  • verapamil
• carvedilol
• ciprofloxacin
• cladribine
• clozapine
• conivaptan
• cyclosporine
• denosumab
• deferasirox
• diabetes medications, such as:
  • acarbose
  • canagliflozin
  • glyburide
  • insulin
  • linagliptin
  • lixisenatide
  • metformin
  • repaglinide
• digoxin
• echinacea
• elagolix
• eliglustat
• enzalutamide
• fingolimod
• flibanserin
• glecavir and pibrentasvir
• grapefruit juice
• HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs), such as:
  • efavirenz
  • etravirine
  • nevirapine
• HIV protease inhibitors, such as:
  • atazanavir
  • indinavir
  • ritonavir
  • saquinavir
• ledipasvir
• leflunomide
• lumacaftor and ivacaftor
• macrolide antibiotics, such as:
  • clarithromycin
  • erythromycin
• mifepristone
• mitotane
• modafinil
• natalizumab
• ocrelizumab
• ozanimod
• pimecrolimus
• protein kinase inhibitors, such as:
  • ceritinib
  • crizotinib
  • dasatinib
  • imatinib
  • nilotinib
• quinine
• rifabutin
• rifampin
• roflumilast
• John’s wort
• sarilumab
• seizure medications, such as:
  • carbamazepine
  • phenobarbital
  • phenytoin
  • primidone
• star fruit
• siponimod
• stiripentol
• tacrolimus
• tocilizumab
• vaccines
• velpatasvir
• warfarin

Frequently Asked Questions