What is it used for?
- Severe active rheumatoid arthritis, including juvenile arthritis.
- Wilson's disease.
- Chronic active hepatitis.
- Excessive excretion of the amino acid cystine in the urine due to an inherited problem with the kidneys (cystinuria).
- Lead poisoning.
How does it work?
Distamine tablets contain the active ingredient penicillamine, Penicillamine has various properties that allow it to be used for several different conditions. (NB. Penicillamine tablets are also available without a brand name, ie as the generic medicine.)
Penicillamine is mainly used to treat rheumatoid arthritis and is referred to as a disease-modifying antirheumatic drug (DMARD). Unlike painkillers, these medicines work by suppressing the excessive activity of the immune system that causes the inflammation of the joints in rheumatoid arthritis. This actually slows progression of the underlying disease. DMARDs are used when painkillers called non-steroidal anti-inflammatory drugs (NSAIDs, eg ibuprofen, diclofenac, naproxen) do not provide sufficient relief from the pain of the arthritis. However, unlike NSAIDs, they can take up to six months to produce their full effect, so they don't provide immediate relief from the pain.
It is not understood exactly how penicillamine works when used to treat rheumatoid arthritis. However, it is known that it reduces the blood levels of certain inflammatory chemicals that the body's immune system produces in rheumatoid arthritis. Once these have fallen, the inflammation of the joints lessens, which helps relieve the pain.
You should not expect this medicine to reduce the pain in your joints for at least 6 to 12 weeks after starting treatment, because it can take this long to start working. If it has had no effect after one year of treatment then your doctor will ask you to stop taking it.
Penicillamine is also a type of molecule called a chelating agent. It binds to several heavy metals, including copper, lead and mercury, forming complexes. These complexes are readily removed from the body by the kidneys and are excreted in the urine.
This property of penicillamine means that it can be used to treat poisoning with heavy metals such as lead. It is also how it works in Wilson's disease, where there is a harmful build-up of excess copper in the body. Penicillamine binds to the excess copper, and allows the body to get rid of it in the urine.
Finally, penicillamine can be used to treat a condition called cystinuria, where excessive amounts of the amino acid cystine are excreted in the urine due to a problem with the kidneys. The excessive cystine passing through the kidneys into the urine can cause stones of cystine to form in the kidneys. Penicillamine reduces the amount of cystine that the kidneys filter into the urine. This helps prevent stones forming and allows existing stones to gradually dissolve.
- Despite the apparent similarity in their names, it is important not to confuse penicillamine with the antibiotic penicillin. The two are different and have different uses.
- Penicillamine tablets should be taken on an empty stomach at least half an hour before meals, or on retiring to bed.
- This medicine may cause a decrease in the normal amounts of blood cells in your blood. For this reason, you will need to have regular blood tests to check the composition of your blood. Your blood will usually be tested before you start treatment, every one or two weeks for the first two months of treatment and then every four weeks. (Longer intervals may be adequate for cystinuria and Wilson's disease.) You should consult your doctor immediately if you experience any of the following symptoms during treatment, as these could indicate a problem with your blood cells: unexplained bruising or bleeding, purple spots, sore throat, mouth ulcers, high temperature (fever), feeling tired or general illness.
- You will also need to have a urine test before you start treatment, every one or two weeks for the first two months of treatment and then every four weeks. (Longer intervals may be adequate for cystinuria and Wilson's disease.) This is to check for protein in your urine and your kidney function and to ensure that no problems are being caused by the medication.
- If you get a rash after starting treatment (even after several months or years of treatment) you should consult your doctor, as your dose of this medicine may need reducing.
Use with caution in
- Elderly people.
- Decreased kidney function.
- Allergy to penicillin-type antibiotics.
- People with rheumatoid arthritis who are having gold treatment or have previously had side effects to gold treatment.
Not to be used in
- Moderate to severe decrease in kidney function.
- Skin disease called lupus erythematosus, in which there are red scaly patches of skin, especially over the nose and cheeks.
- People with abnormal blood counts caused by this medicine (agranulocytosis, aplastic anaemia, or severe thrombocytopenia).
This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.
If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.
Pregnancy and breastfeeding
Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
- The safety of this medicine during pregnancy has not been established. It may be harmful to a developing foetus. It is not recommended for use during pregnancy, unless considered essential by your doctor and the benefits outweigh any potential risks to the foetus. Seek medical advice from your doctor.
- It is not known if this medicine passes into breast milk. It should not be used by breastfeeding mothers unless considered essential by your doctor. Seek medical advice from your doctor.
- Take this medication half to one hour before food.
- Do not take iron preparations or indigestion remedies at the same time of day as this medication.
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.
- Decreased appetite.
- Skin rashes
- Loss of taste (this can occur about six weeks after starting treatment, but usually gets better within six weeks even if you keep taking the medicine).
- Mouth ulcers.
- Decreases in the normal amounts of blood cells in the blood (see warning above).
- Protein in the urine.
- Blood in the urine (stop taking this medicine and consult your doctor immediately if you experience this).
- Inflammation in the lungs (bronchiolitis, pneumonitis).
- Kidney disorders.
- Breast enlargement.
- Hair loss.
- Skin disease resembling lupus erythematosus, in which there are red scaly patches of skin, especially over the nose and cheeks.
- Conditions resembling myaesthenia gravis.
- Muscle inflammation (polymyositis), sometimes associated with skin rash (dermatomyositis).
The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.
For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.
How can this medicine affect other medicines?
You should tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to ensure that the combination is safe.
You should not take iron tablets, zinc, or indigestion remedies (antacids) in the two hours before or after taking your penicillamine tablets, as these medicines reduce the absorption of penicillamine from the gut and could make it less effective.
You should not take digoxin in the two hours before or after taking your penicillamine tablets, as the penicillamine may reduce the absorption of digoxin from the gut and could make it less effective.
Penicillamine should ideally not be used in combination with gold treatment, as this may increase the risk of side effects.
There may be an increased risk of side effects on the blood cells if penicillamine is taken with other medicines that can reduce the ability of the bone marrow to make blood cells. These include the following:
- chemotherapy medicines
There may be an increased risk of kidney problems if penicillamine is taken in combination with other medicines that can cause kidney problems. These include the following:
- aminoglycoside antibiotics, eg gentamicin, tobramycin
- non-steroidal anti-inflammatory drugs (NSAIDs, eg indometacin, naproxen, diclofenac, ibuprofen)
Other medicines containing the same active ingredient
Penicillamine tablets are also available without a brand name, ie as the generic medicine.