Each unit carries about 250 milligrams of iron. Over the course of therapy iron builds up in the body's tissues, and after approximately twenty transfusions a patient may end up with toxic levels. Iron has powerful oxidant activity that can damage tissue. When excessive iron accumulates in the heart, liver, lungs, bone marrow and endocrine organs, the stage is set for a broad array of possible diseases, including heart failure, diabetes, arthritis, cirrhosis and fibrosis of the liver, gallbladder disorders, depression, impotence, infertility, and cancer. Desferal, given separately from blood infusion, is administered anywhere from three to seven times a week.
Some patients receive twice-daily subcutaneous injections.
Others receive slow intravenous infusion by way of a portable, battery-operated pump worn over a period of about eight hours, often at night. Patients can expect to receive up to two grams of Desferal for each unit of blood transfused. Typically, a physician will initiate treatment with one gram, gradually adjusting the dose upward until it reaches no more than three grams a day. Urine samples reveal how much iron the patient is excreting and help the physician adjust the dose of Desferal to maintain negative iron balance. Though Desferal is slow acting removing only 6 to 10 mg of iron per infusion it can maintain negative iron balance even when blood transfusions continue.