Questions About Iron OverLoad And Desferal
How much iron is there in a normal person's body?
In most normal adults are about 4 grams of iron. Three grams are in their red cells, and one gran is kept in a store in the liver cells, in case they need it. People get thier iron by absorbing a snall amount from the food they eat. Usually people absorb only about one tenth of the iron in their food.
There is no natural way of getting rid of iron once it is in your body, but a small amount gets lost every day, in cells that rub off the surface if your skin, or from the lining of your gut.
How Does regular tranfusion lead to iron overload?
Every unit of blood contains about one fifth of a gram of iron, so a thalassemic person who recieves 20 units of blood a year, also receives about 4 grams of iron a year. There is no natural way of getting rid of this iron, so it had to be stored.
At First the extra iron is stored in the liver. The liver seems ablt to store away about 20 grams of iron without much difficulty. Most thalassemic children are able to store all the iron they receive safely, up to about 11 years of age. Your liver may enlarge a little to fit it all in, so it may be easier to feel the liver edge in the thalassemics than in other people. There is no harm in this. However, after about 11 years of age, the stores are full, and the iron begins to accumulate in places like the heart, where it can do damage. Figure 7 shows the parts of the body that can be damaged when iron is allowed to build up.
How does the iron that accumulates in the body do damage?
The right amount of iron is important for your body to be able to work normally. There is a small amount of iron in every cell. But if there is too much iron in a cell, part of call may be damaged, and even die. Once this starts to happen it creates more problems, because the iron that was stored in that cell is freed, and has to be put into other cells.
How does Desferal help?
Desferal helps in two ways. Firstly, it picks up iron from your cells and brings it out in your urine, and this keeps down the total amount in your body from interfering with its normal functions.
When should you start iron chelation therapy?
In principle, you should start as soon as there is more than the usual amount of iron in your body. The iron level starts to rise very soon after regular transfusions are started, so you need to discuss Desferal treatment with your doctor at an early stage.
Is Desferal really the only available drug for getting rid of excess iron?
At present, Yes. Another drug, DTPA, thats had to be given through a pump in the same way, is sometimes used for patients who cannot have Desferal for some reason.
There is a lot of research to try to find a new drug that would work as well as Desferal, but could taken by mouth. This work is described more fully on page 53. However, drug development takes as long time, so at present there really is no alternative to the pump. If you want to benefit fully from any pill in the future, you should make the effort to take your Desferal now.
How is Desferal used?
Desferal is most effective when it is given by "the pump" over 8-12 hours. In practice, this is done as follows.
Desferal comes in vials of a white powder (Figure 11a). There are 500mg, which is the same as half of a gram, in each vial.
The Desferal is dissolved in a convenient amount of distilled water (about 2.5ml of distilled water per 500mg ampoule), and then drawn up into a syringe (Figure 11b).
The syringe is placed in a small electronic pump, that pushes the plunger of the syringe in very slowly, so that the drug is injected in the period of time that you want (Figure 12). The pump has controls that allow you to set the time for emptying the syringe, and an alarm that warns you if the syringe get stuck, or when the drug has all been injected.
The syringe with the Desferal is connected to a thin plastic tube that leads to a very tiny needle. The needle is inserted under the skin, So that the Desferal is squeezed out into the space between the skin and the muscles or fat that lies underneath (Figure 13). The pump can be carried in a sort of shoulder-holster during the day (Figure 14) which can be covered with loose clothes. Or it can be put at the bedside during night.
Is there any special place to infuse the deferal?
There are not any special places- but certainly no one infuses Desferal into their face! Some people prefer to use their stomach, or their thigh,or their upper arm. It is good idea to change the place you use for injections regularly, to avoit particular places getting hard or sore.
Does it hurt to put the pump on?
Really, it hardly hurts at all when you put the needle in, because it is so tiny. We usually advice parents to try the pump out on themselves once, to find out for themselves just how little it does hurt. But all the same, same people, specially small children, get worried about it because it happenes every day. There is a special cream with some local anesthetic called "Emla Cream," that you can put on the place where the needle will go, and it takes any discomfort away. The only thing is, you have to put it on about 1 hour before you put the pump on. But many families find it is and enormous help. and put it on their child's hand or arm before transfusions, too.
(The instructions with the cream tell you to use half a tube every time! You do not need anything like that amount, for transfusions or the pump. You just need to put a smear of the cream in the right place. and one tube should last you about 2 to 3 weeks!)
Can Desferal cause bad reactions, at the place where it is injected, or generally?
In a very few people, injecting Desferal had caused a general reaction. These reactions have been of several types; feeling generally unwell, tingling, dizziness, difficulty in breathing etc. If any of these things happens, the injection should be stopped immediately. General reactions do not happen without warning in patients on regular treatment. Either they happen in patients just starting on treatment. or else the symptoms develop gradually.
General reactions can be treated by "desensitization." This means a series of intravenous injections of increasing doses of Desferal, starting with a very small dose indeed. Desensitization is done in hospital, under close medical supervision.
Reactions at the site of the infusion usually consist of redness and swelling. They may be prevented by giving an anti-histamine by mouth before giving the infusion of Desferal.
Alternatively, hydrocortisone can be addes to the injection. in a maximum dose of 2mg per ml. Sometimes, after many infusions. Desferal can cause rather hard tender lumps where it is injected. These can be prevented by filling the infusion-tubing with a asmall amount of hyaluronidase before setting up the pump.
Can Desferal cause any other problems?
Desferal can cause disturbances of the eyes, and of hearing, and can cause slowing of growth. As a rule, such problems occur only when high doses of desferal are used, and when the iron overload is small. They can usually be reversed by decreasing the dose of desferal. Everyone on regular deferal treatment should be examined regularly. So that problems arising from the treatment can be discovered at an early stage, and prevented by modifying the Desferal dose.
Must desferal be taken every day?
Different people need different amounts of Desferal, so you need to work out your own treatment programme with your own doctor. You must follow the ageed programme exactly, if you want the best results.
What is the right dose of Desferal?
We are still not quite sure about this. We think that you should have at least 25mg/kg/day, and not more than 60/mg/kg/day.
Ofcourse, the amount that people actually have depends on a number of things. Many thalassemics live in countries with limited health services, and cannot afford much Desferal. In countries where Desferal is provided free of charge, different doctors may prescribe different amounts of Desferal, And then, some thalassemics dont manage to take as much Desferal as the doctors tell them to.
If you want to work out the dose you are actually having, (Figure 15) may help you. Count up how many bottles you use per week, and make sure you know your weight in kilograms. Then you can work out approximately what dose you are receiving, in milligrams per kilogram per day (mg/kg/day) from the chart.
Isn't it possible to increase the daily dose of Deferal, and reduce the number of days on which you take "The Pump"?
Does anyone use injections of Desferal into a vein?
Under Certain cicumstances. It can be very useful to infuse large doses of Desferal intravenously. This has to be done in hospital. However, courses of intravenous treatment are in addition to subcutaneous infusions, not a subtitute for them.
Should we take Deferal even when we have an illness?
We think its better to stop using Desferal untill you know the cause of your illness. This is because there is a family of germs, called Yersinia, that can use Desferal to grow on. These germs can cause an instestinal infection. Therefore, if you have a fever, or a tummy-ache, or diarrhoea, it is best to stop your Desferal, because if the fever is due to a Yersinia infection, the Desferal could make the infection worse. Once you know the illness is not due to Yersinia, you should start taking the Desferal again.
Why are most patients who are on Desferal treatment, advised to take Vitamin C as well
Because Vitamin C increases the amount of iron that the Desferal can take out of your body, especially if you have a lot of iron in you body. Also, iron in you body can destroy vitamin C, so you need more of it than other people.
Thalassemics with a heart problem are usually advised to stop taking Vitaming C.
Are There particular rules about taking Vitamin C?
Yes. Firstly, you should start taking Vitamin C only after you have been receiving Desferal for atleast one month.
Secondly, you should not take more than 200mg each day and children under 3 should only take about 100mg.
Finally, it is best (but not always possible) to take the Vitamin C a couple of hours after starting the Desferal.
Can we do anything else to reduce iron overload?
Drinking tea with meals can reduce the amount of iron you absorb from your food. However, this is only really important when you hemoglobin level is low (less than 11g/dl), or if you have thalassemia intermedia. If you are on a high transfusion scheme, there is no point in taking extra tea.
Don't People find it very difficult to take Desferal infusions all the time?
Ofcourse they do. Infact, quite often they do not take as many infusions as their doctor tells them to. This is less of a problem for children, because their parents help them. If the parents are not afraid of treatment, the child usually accepts it well.
But when people with adolescence, it is necessary and natural for them to start looking after themselve. They want to be normal free adults, and then they can find the discipline of the pump, and all the rest of the treatment, it is particularly hard. Young thalassemic adults need aa lot of support and encouragement from the doctors and nurses. But usually when they get older still, they can accept the treatment better again.
It is very important to be truthfull with yourself and your doctor, about how much you really take. We all know it is difficult, but if you get ill, you doctor must have a clear picture of what really has been happening, so as to arrange the right treatment for you.
To help you keep a record, it is a good idea to keep a small calendar with your Desferal things, and to mark every day when you actually have an infusion. Some treatment centers give thalassemic patients a clinical record book of their own, which includes a calender to mark. Some centers ask patients to bring back their empty Desferal bottles, so as to keep a seperate check on the amount they are taking.
How can you tell when to start treatment, and whether the treatment is working?
The best guide is your Serum Ferritin level. Ferritin is a substance that holds iron in the stores in your liver and other tissues. A small amount of ferritin gets out into the blood, and the amount in the blood reflects the amount of your iron stores. That is why we use it as a guide, to tell us when you need Desferal, and whether you are having too little or too much, Some centers also measure the amount of iron that comes out in your urine after an infusion, to check that you are having the right amount.
What level of Serum Ferritin means that iron-overload is undercontrol?
We are not completely sure of the right level of serum ferritin to aim for, but this is what we think at present.
The Serium Ferritin level in normal people is between 100 and 400 mg/ml.
Thalassemic children start off at this level. If they are transfused but have no Desferal, their serum ferritin rises steadily (but at different rates in different children). By the time the child is 2 years old the serum ferritin is usually more than 2,000, and by the time the child is 5, it is usually 5-7,000. By the time they are 13, it may be as high as 10,000, and towards the end of thier life, it will be about 14,000.
Thalassemics on Desferal treatment can have different serum ferittin levels, depending on how long they have been on Desferal. how much Desferal they actually take, etc. The (Table) shows what different level means.
What serum ferittin level should we aim for?
We do not think that thalassemics should aim for as low serium ferritin as other people, because thalassemics have to live all the time with their Desferal treatment. In people without iron overload, Desferal can have damaging effects. Desferal does not hurt thalassemics because they have so much iron in their body. Thalassemics need Desferal to protect them against the Desferal. They need a balance. At present we think that the best balance is reached when the serum ferritin is about 1,000 to 1,5000 ng/ml.