Arsenic trioxide is a chemotherapy drug and is also called Trisenox or ATO.
It is a treatment for a type of acute myeloid leukaemia called acute promyelocytic leukaemia (APL). Researchers are also looking into it as a treatment for other types of cancer.
How it works
Arsenic works by speeding up the death of leukaemic cells and encouraging normal blood cells to develop properly. It does this by working on particular proteins within the cell.
How you have it
You have arsenic trioxide as a drip into the bloodstream. The drip lasts for between 1 and 2 hours. But if you have a reaction to the drip you may have it more slowly over 4 hours.
Drugs into your bloodstream
You have the treatment through a drip into your arm or hand. A nurse puts a small tube (a cannula) into one of your veins and connects the drip to it.
You might need a central line. This is a long plastic tube that gives the drugs into a large vein, either in your chest or through a vein in your arm. It stays in while you’re having treatment, which may be for a few months.
When you have it
You may have arsenic trioxide to get rid of the leukaemic cells (induction treatment) or to stop your leukaemia coming back (consolidation treatment).
You have arsenic trioxide every day until there is no sign of the leukaemia in your bone marrow. This is called remission induction. You have this induction treatment for up to 50 to 60 days.
You usually have 25 doses of arsenic trioxide. You generally have it for 5 days a week with a 2 day break, for 5 weeks.
You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.
Before treatment and regularly during the treatment you have a test of your heart called an ECG.
We haven't listed all the side effects. It's very unlikely that you will have all of these side effects, but you might have some of them at the same time.
How often and how severe the side effects are can vary from person to person. They also depend on what other treatments you're having. For example, your side effects could be worse if you're also having other drugs or radiotherapy.
When to contact your team
Your doctor, nurse or pharmacist will go through the possible side effects. They will monitor you closely during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:
- you have severe side effects
- your side effects aren’t getting any better
- your side effects are getting worse
Early treatment can help manage side effects better.
Coping with side effects
We have more information about side effects and tips on how to cope with them.
Common side effects
Each of these effects happens in more than 10 ou of 100 people (10%). You might have one or more of them. They include:
Tiredness and weakness (fatigue)
Tiredness and weakness (fatigue) can happen during and after treatment - doing gentle exercises each day can keep your energy up. Don't push yourself, rest when you start to feel tired and ask others for help.
Swelling of hands and feet (oedema)
You may have swelling of your hands and legs due to a build up of fluid (oedema).
High temperature (fever)
If you get a high temperature, let your treatment team know straight away. Ask them if you can take paracetamol to help lower your temperature.
Bone and muscle pain
You might feel some pain from your muscles and joints. Speak to your doctor or nurse about what painkillers you can take to help with this.
Skin problems include a skin rash, dry skin and itching. This usually goes back to normal when your treatment finishes. Your nurse will tell you what products you can use on your skin to help.
High sugar levels in the blood
You have regular blood and urine tests to check this. If you have diabetes you may need to check your blood sugar levels more often than usual.
Numbness and tingling in fingers and toes
Numbness or tingling in fingers or toes is often temporary and can improve after you finish treatment. Talk to the team looking after you when you first notice this.
Contact your advice line if you have diarrhoea, such as if you've had 4 or more loose watery poos (stools) in 24 hours. Or if you can't drink to replace the lost fluid. Or if it carries on for more than 3 days. Your doctor may give you anti diarrhoea medicine to take home with you after treatment. Eat less fibre, avoid raw fruits, fruit juice, cereals and vegetables, and drink plenty to replace the fluid lost.
Feeling or being sick
Feeling or being sick is usually well controlled with anti sickness medicines. Avoiding fatty or fried foods, eating small meals and snacks, drinking plenty of water, and relaxation techniques, can all help.
You might have liver changes that are usually mild and unlikely to cause symptoms. They usually go back to normal when treatment finishes. You have regular blood tests to check for any changes in the way your liver is working.
Headaches and dizziness
Let your doctor or nurse know if you have headaches. They can give you painkillers. Don’t drive or operate machinery if you feel dizzy.
Shortness of breath
Talk to the tema looking after you about this.
You may get heart problems, such as angina, heart failure or a heart attack. You will have regular heart checks during and after the treatment. Tell your doctor or nurse straight away if you have any chest pain.
Changes in mineral levels in the blood
You wil have regular blood tests to monitor this.
This is a group of serious side effects. These effects happen in more than 10 out of 100 people (10%).They include:
- difficulty breathing
- high temperature (fever)
- sudden weight gain
- unable to pass urine
- fast heart beat
Occasional side effects
Each of these effects happens in between 1 and 10 out of 100 people (1 and 10%). You might have one or more of them. They include:
- increased risk of getting an infection
- breathlessness and looking pale
- bruising, bleeding gums or nosebleeds
- fluid around the heart or lungs
- weight gain
- kidney changes
- eye changes
- low blood pressure
- herpes virus
- tummy (abdominal) pain
- bone pain
Rare side effects
This side effect happens in fewer than 1 out of 100 people (1%).
There have been a few reports of people developing a second cancer some years after arsenic trioxide treatment. It is not clear whether this was due to the arsenic or not.
What else do I need to know?
Other medicines, foods and drink
Cancer drugs can interact with some other medicines and herbal products. Tell your doctor or pharmacist about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies.
Pregnancy and contraception
This treatment might harm a baby developing in the womb. It is important not to become pregnant or father a child while you're having treatment and for a few months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.
It is not known whether this treatment affects fertility in people. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.
Don’t breastfeed during this treatment because the drug may come through into your breast milk.
Treatment for other conditions
Always tell other doctors, nurses, pharmacists or dentists that you’re having this treatment if you need treatment for anything else, including teeth problems.
Don’t have immunisations with live vaccines while you’re having treatment and for up to 12 months afterwards. The length of time depends on the treatment you are having. Ask your doctor or pharmacist how long you should avoid live vaccinations.
In the UK, live vaccines include rubella, mumps, measles, BCG, yellow fever and the shingles vaccine (Zostavax).
- have other vaccines, but they might not give you as much protection as usual
- have the flu vaccine (as an injection)
- be in contact with other people who have had live vaccines as injections
Avoid close contact with people who have recently had live vaccines taken by mouth (oral vaccines) such as oral polio or the typhoid vaccine.
This also includes the rotavirus vaccine given to babies. The virus is in the baby’s poo for up to 2 weeks and could make you ill. So avoid changing their nappies for 2 weeks after their vaccination if possible. Or wear disposable gloves and wash your hands well afterwards.
You should also avoid close contact with children who have had the flu vaccine nasal spray if your immune system is severely weakened.
More information about this treatment
For further information about this treatment go to the electronic Medicines Compendium (eMC) website.
You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.