eMedicine Specialties > Pediatrics: General Medicine > Hematology
Hemoglobin H Disease: Treatment & Medication
Updated: Jul 16, 2009
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
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Treatment
Medical Care
- General supportive care in hemoglobin H disease (HbH disease) includes transfusions, which may be needed periodically or in periods of severe anemia, such as during parvovirus infections. Guidelines for transfusion in neonates and older children have been established.7 Usually, patients with hemoglobin H disease live fairly normal lives and require few transfusions. Hemoglobin levels usually range from 7-10 g/dL. Transfusion therapy is reserved for patients with severe anemia (usually <7 g/dL) and symptomatic anemia. Hemolytic episodes may be triggered either by drug use or by infection. The use of special RBC units (eg, washed, irradiated, leucocyte depleted) usually is not required.
- Carefully document iron deficiency with laboratory testing prior to the administration of supplemental iron. Many patients with apparent iron deficiency can have iron overload (hemachromatosis), the effects of which can contribute to morbidity and mortality.
- In very severe cases, allogeneic bone marrow transplantation may be considered, which is curative, since the hematopoietic system of the patient is replaced by that of the donor. A sibling who is fully matched for human leukocyte antigen (HLA) and who is, at most, a carrier for a -thalassemia (deletion of 2 a -globin genes) is the most suitable donor. However, because of the toxicity of the procedure, bone marrow transplantation should be limited to the most severely affected patients.
Surgical Care
- Splenectomy may be beneficial in some patients. Usually, splenectomy is reserved for patients with symptoms of hypersplenism, as reflected by leukopenia, thrombocytopenia, and worsening anemia or, in patients who were previously stable, development of a transfusion requirement.
Consultations
- Patients with hemoglobin H disease usually undergo close follow-up monitoring by a hematologist who can coordinate care and treat the patient during acute hemolytic and anemic episodes.
Diet
- In patients with elevated ferritin levels, the diet should be low in iron.
Medication
In general, no medications are needed in hemoglobin H disease (HbH disease); however, if the reticulocyte count is elevated, supplement the diet with folic acid. If a patient has an elevated ferritin level, consider chelation therapy with deferoxamine (Desferal) or deferasirox (Exjade). Deferasirox is preferred because it is orally administered, whereas deferoxamine is administered intravenously or subcutaneously.
Vitamins
This is a supplement with folic acid, a vitamin necessary for red blood cell production.
Folic acid (Folvite)
Necessary coenzyme for nucleoprotein synthesis and maintenance in patients with erythropoiesis.
Adult
1-3 mg/d PO/IV/IM/SC
Pediatric
0-12 months: 0.5-1 mg/d PO/IV/IM/SC
1-10 years: Up to 1 mg/d PO/IV/IM/SC
>11 years: Administer as in adults
Increase in seizure frequency and subtherapeutic levels with concurrent phenytoin
Documented hypersensitivity
Pregnancy
A - Fetal risk not revealed in controlled studies in humans
Precautions
Pregnancy category C if >0.8 mg/d; benzyl alcohol may be present as preservative and is associated with fatal gasping syndrome in premature infants; resistance to treatment may occur in patients with alcoholism and other vitamin deficiencies
Chelation agents
Iron overload (usually from multiple transfusions) may require chelation therapy, which usually begins when the ferritin level is greater than 1000 ng/mL.
Deferoxamine mesylate (Desferal)
Freely soluble in water. Approximately 8 mg of iron is bound by 100 mg of deferoxamine. Excreted in urine and bile and discolors the urine red. Readily chelates iron from ferritin and hemosiderin but not transferrin. Most effective when provided to the circulation continuously by means of infusion. May be administered by IM injection, slow infusion, SC bolus, or continuous infusion. Does not effectively chelate other trace metals of nutritional importance.
Adult
Acute iron intoxication: 1 g IM followed by 500 mg 4 h and 8 h later; may repeat with 500 mg IM q4-12h; not to exceed 6 g/d
Alternative: 1 g IV at a rate not exceeding 15 mg/kg/h followed by 500 mg q4h for 2 doses; administer additional IV infusion slowly over 24 h; not to exceed 6 g/d
Pediatric
<3 years: Not established
>3 years:
IM: 50 mg/kg IM initially; not to exceed 1 g/dose; may repeat with half dose 4h and 8h later; similar IM doses can be administered at q4h for next 24 h if clinical findings warrant
IV: 20 mg/kg IV initially over 1-2 min followed by an infusion of 60 mg/kg over 6-8 h; rapid injection can cause hypotension; if clinically indicated, additional therapy can be administered
IM in most circumstances
SC: 20-50 mg/kg/d SC continuous infusion over 8-12 h; not to exceed 2 g/d
Concomitant administration with prochlorperazine can cause transient loss of consciousness
Documented hypersensitivity; absence of acute iron poisoning; severe renal disease and anuria (consider dose reduction after loading dose)
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Tachycardia, hypotension, and shock may occur with chronic therapy (can increase cardiovascular collapse due to iron toxicity); adverse effects in GI tract include abdominal discomfort, nausea, vomiting, and diarrhea (may increase symptoms of acute iron toxicity); flushing; fever; rapid IV injection can cause hypotension
Deferasirox (Exjade)
Tab for oral susp. PO iron chelation agent demonstrated to reduce liver iron concentration in adults and children who receive repeated RBC transfusions. Binds iron with high affinity in a 2:1 ratio. Approved to treat chronic iron overload due to multiple blood transfusions. Treatment initiation recommended with evidence of chronic iron overload (ie, transfusion of about 100 mL/kg packed RBCs [about 20 U for 40-kg person] and serum ferritin level consistently >1000 mcg/L).
Adult
Initial: 20 mg/kg PO qd on empty stomach 30 min ac; calculate dose to nearest whole tablet
Maintenance: Adjust dose by 5- to 10-mg/kg/d increments q3-6mo according to serum ferritin level trends; not to exceed 30 mg/kg/d
Note: Dissolve tab completely in water, orange juice, or apple juice, then immediately drink susp; resuspend any remaining residue in small volume of liquid and swallow
Pediatric
<2 years: Not established
>2 years: Administer as in adults
Data limited; do not take with aluminum-containing antacids
Documented hypersensitivity
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Common adverse effects include diarrhea, nausea, abdominal pain, headache, pyrexia, cough, and rash; may increase serum creatinine and hepatic enzyme levels; decrease dose with persistent elevation of serum creatinine level; may cause auditory and visual disturbances; slight decreases in serum copper and zinc levels may occur; dissolve tab completely in water, orange juice, or apple juice and drink resulting susp immediately (do not swallow tab whole, do not chew or crush); measure serum ferritin levels monthly and adjust dose q3-6mo based on serum ferritin trends
More on Hemoglobin H Disease |
| Overview: Hemoglobin H Disease |
| Differential Diagnoses & Workup: Hemoglobin H Disease |
 Treatment & Medication: Hemoglobin H Disease |
| Follow-up: Hemoglobin H Disease |
| Multimedia: Hemoglobin H Disease |
| References |
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References
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Further Reading
Keywords
hemoglobin H disease, alpha-thalassemia syndrome, α-thalassemia syndrome, HbH disease, chronic hemolytic anemia, genetic disorder, thalassemia, anemia, alpha-globin gene, globin protein, malaria protection, alpha-globin chains, jaundice, hepatosplenomegaly, folic acid deficiency, iron deficiency, hydrops fetalis, marrow hyperplasia, bone thinning, maxillary hyperplasia, anemia, treatment, diagnosis
