Sickle-Cell Disease Treatment

Cyanate

Dietary cyanate, from foods containing cyanide derivatives, has been used as a treatment for sickle- cell anemia. In the laboratory, cyanate and thiocyanate irreversibly inhibit sickling of red blood cells drawn from sickle cell anemia patients. However, the cyanate would have to be administered to the patient for a lifetime, as each new red blood cell created must be prevented from sickling at the time of creation. Cyanate also would be expelled via the urea of a patient every cycle of treatment. Also see nicosan.

Painful (vaso-occlusive) crisis

Most people with sickle-cell disease have intensely painful episodes called vaso-occlusive crises. The frequency, severity, and duration of these crises, however, vary tremendously. Painful crises are treated symptomatically with analgesics; pain management requires opioid administration at regular intervals until the crisis has settled. For milder crises, a subgroup of patients manage on NSAIDs (such as diclofenac or naproxen). For more severe crises, most patients require inpatient management for intravenous opioids; patient-controlled analgesia (PCA) devices are commonly used in this setting. Diphenhydramine is also an effective agent that is frequently prescribed by doctors in order to help control any itching associated with the use of opioids.

Folic acid and penicillin

Children born with sickle-cell disease will undergo close observation by the pediatrician and will require management by a hematologist to assure they remain healthy. These patients will take a 1 mg dose of folic acid daily for life. From birth to five years of age, they will also have to take penicillin daily due to the immature immune system that makes them more prone to early childhood illnesses.

Acute chest crisis

Management is similar to vaso-occlusive crisis, with the addition of antibiotics (usually a quinolone or macrolide, since wall-deficient ["atypical"] bacteria are thought to contribute to the syndrome), oxygen supplementation for hypoxia, and close observation. Should the pulmonary infiltrate worsen or the oxygen requirements increase, simple blood transfusion or exchange transfusion is indicated. The latter involves the exchange of a significant portion of the patients red cell mass for normal red cells, which decreases the percent of haemoglobin S in the patient's blood.

Hydroxyurea

The first approved drug for the causative treatment of sickle-cell anaemia, hydroxyurea, was shown to decrease the number and severity of attacks in a study in 1995 (Charache ''et al.'') and shown to possibly increase survival time in a study in 2003 (Steinberg ''et al.''). This is achieved, in part, by reactivating fetal haemoglobin production in place of the haemoglobin S that causes sickle-cell anaemia. Hydroxyurea had previously been used as a chemotherapy agent, and there is some concern that long-term use may be harmful, but this risk has been shown to be either absent or very small and it is likely that the benefits outweigh the risks.

Bone marrow transplants

Bone marrow transplants have proven to be effective in children.

Future treatments

Various approaches are being sought for preventing sickling episodes as well as for the complications of sickle-cell disease. Other ways to modify hemoglobin switching are being investigated, including the use of phytochemicals such as nicosan. Gene therapy is under investigation.

Another treatment being investigated is Senicapoc.