DescriptionAn in-depth report on the types, diagnosis, treatment, and prevention of anemia.
Alternative NamesIron Deficiency; Pernicious Anemia
Oral iron supplements are the most effective agents for restoring iron levels for people who are iron deficient, but they should be used only when dietary measures have failed. It should be noted that they will not correct anemias that are not due to iron deficiency. One study reported that physicians prescribed iron pills for 64% of patients with anemia without performing tests to confirm whether iron deficiency was actually the cause. The study suggested that iron replacement was appropriate in less than half of these patients. Iron replacement therapy can cause gastrointestinal problems, sometimes severe ones. Excess iron may also contribute to heart disease, diabetes, and certain cancers. Experts generally advice against iron supplements in anyone with a healthy diet and no indications of iron deficiency anemia. Of interest, however, was a 2003 study suggesting that supplements helped reduce fatigue in women with low iron stores but no signs of anemia.
Treatment of Anemia of Chronic Disease. In general, the best treatment for anemia of chronic diseases is treating the disease itself. In some cases, iron deficiency accompanies the condition and requires iron replacement. Erythropoietin, most often administered with intravenous iron, is being investigated with success in some patients.
Treatment of Megaloblastic Anemia. The standard treatments for megaloblastic anemia are vitamin B12 injections and folic acid replacement.
Supplement Forms. To replace iron, the preferred forms of iron tablets are ferrous salts, usually ferrous sulfate (Feosol, Fer-In-Sol, Mol-Iron). Other forms include ferrous fumarate (Femiron, FerroSequels, Feostat, Fumerin, Hemocyte, Ircon), ferrous gluconate (Fergon, Ferralet, Simron), polysaccharide-iron complex (Niferex, Nu-Iron), and carbonyl iron (Elemental Iron, Feosol Caplet, Ferra-Cap). Specific brands and forms may have certain advantages. The following are some examples:
Regimen. The general guidelines for iron replacement are as follows:
Other tips for taking iron are as follows:
Full recovery takes six to eight weeks. (Recovery will take longer in people with internal bleeding that is not under control.) Iron replacement therapy must continue for about six months, even if anemia has been reversed. Treatment must be continued indefinitely for people with chronic bleeding; in such cases, iron levels should be closely monitored.
Side Effects. Common side effects of iron supplements include the following:
Interactions with Other Drugs. Certain medications, including antacids, can reduce iron absorption. Iron tablets may also reduce the effectiveness of other drugs, including the antibiotics tetracycline, penicillamine, and ciprofloxacin and the Parkinson's Disease drugs methyldopa, levodopa, and carbidopa. At least two hours should elapse between doses of these drugs and iron supplements.
Supplementary Agents. The following agents may improve iron absorption:
Intravenous or Injected Iron
In some cases, iron is administered through muscular injections or intravenously. Intravenous iron has the advantage of causing less gastrointestinal discomfort and inconvenience. It may be in the form of iron dextran (Dexferrum, InFed), sodium ferric gluconate complex in sucrose (Ferrlecit), or iron sucrose (Venofer). Ferrlecit or Venofer are proving to be at least equally effective and safer than iron dextran.
Candidates. The injected or intravenous forms should be limited to the following patients with iron deficiency:
Certain patients, even if they meet these qualifications, may not be appropriate candidates or should be monitored closely for complications. They include:
Side Effects. Some side effects differ depending on how the iron is administered and include the following:
For both methods side effects and serious complications can include the following:
Oral and injected iron should never be given at the same time. Intravenous iron therapy may be appropriate for some pregnant women who meet these requirements, depending on the pregnancy term and other factors.
Transfusions and Bloodless Medicine
Transfusions are used to replace blood loss due to injuries and during certain surgeries. They are also commonly used for severely anemic patients who are hospitalized in the intensive care unit for a critical illness. The benefits and risks of transfusions such patients, however, is not entirely clear and are under debate. In a 2002 study, transfusions were associated with higher mortality rates in critically ill and elderly patients with anemia. Some evidence suggests, however, that limiting the amount of blood transfused to maintain a relatively low hemoglobin level may be safer than liberal blood transfusions and still effective in many of these patients (although not those with unstable heart conditions or heart attacks). More work is needed to determine how to use transfusions in the critically ill populations. Donor blood also carries a small risk for transmitting infections and other diseases.
Bloodless Medicine. Bloodless medicine and surgery is a new field designed to reduce or minimize blood loss and transfusions. It also attempts to address the problems in treating certain religious groups, such Jehovah's Witnesses, who refuse transfusions. Some techniques involved in this field include new surgical procedures or drugs that minimize blood loss, the use of erythropoietin, volume expanders (administration of fluids to dilute blood), using tiny blood samples for testing, and methods (e.g., Cell Saver) for recovering and recycling blood during surgery.
Recombinant Human Erythropoietin (rHuEPO)
Erythropoietin is the hormone that acts in the bone marrow to increase the production of red blood cells. It has been genetically engineered as recombinant human erythropoietin (rHuEPO) and is available as epoetin (Epogen, Procrit, Eprex). Novel erythropoiesis stimulating protein (NESP), also called darbepoetin alfa (Aranesp) persists longer in the blood than epoetin alfa and so requires fewer injections.
Levels of erythropoietin are reduced in ACD. It is currently most useful for the following patients:
Antibiotics for H. Pylori
H. pylori, the bacteria that cause peptic ulcers, is associated with anemias from vitamin B12 deficiency and iron deficiency. People whose anemia is associated with H. pylori infection, however, do not respond to iron therapy. Studies are indicating that the eradication of H. pylori infection with antibiotics can reverse anemia in such patients and may lead to long-lasting recovery.
Vitamin Replacement for Megaloblastic Anemia
Vitamin B12 Therapy. Injections of vitamin B12 (usually formulations called cyanocobalamin or hydroxocobalamin), oral folic acid therapy, or both, rapidly reverse the production of abnormally large red blood cells. (Treatments still may not reverse neurologic symptoms if they are extensive or have continued for too long.)
A typical regimen for vitamin B12 replacement is as follows:
Other forms of vitamin B12 are also available and can be used to treat B12 deficiency. Vitamin B12 by nasal spray offers the same advantage of avoiding the need for absorbing the vitamin in the GI tract without the inconvenience of the injections. Some experts feel that even oral B12 in high doses (2,000 mcg/day) can maintain B12 levels once the deficiency is treated.
The injections are safe and have no adverse side effects, but they may mask an underlying medical or psychological condition.
Some physicians give vitamin B12 injections for fatigue and other vague symptoms of general mild discomfort. In one study, 10% of patients in a rural clinic were given regular B12 shots, with 6% of patients having no medical need for them.
Folic Acid Treatment. Folate deficiency is easily remedied in four to five weeks with daily oral doses of one to two milligrams of folic acid. Many doctors give vitamin B12 along with folic acid unless B12 deficiency is definitely ruled out.