British Society of Haematology,(BSH) has come out with Guidelines for use of hydroxycarbamide in Sickle cell disease in children and adults. It aims to outline the current evidence for specific indications and to provide clinician aids for consultation and monitoring of hydroxycarbamide in managing sickle cell anemia. The British Society of Haematology (BSH) has used (GRADE) nomenclature to evaluate levels of evidence and to assess the strength of recommendations.
Sickle cell disease (SCD) is a generic term for an inherited group of disorders that includes homozygous sickle cell anemia (SS), sickle cell/ hemoglobin C (SC) sickle cell/βthalassemia (S/β that) and other compound heterozygous conditions.
Hydroxycarbamide is an inhibitor of ribonucleotide reductase and has been used as an oral anti‐proliferative drug for several decades. Its mode of action in SCD is based on both its ability to increase HbF levels and its ability to reduce intercellular adhesion and hence improve blood flow.
The guidelines involved various parameters which are as follows-
Rationale for hydroxycarbamide
- The benefits of hydroxycarbamide should be discussed with all parents of children, adolescents and adults with SS/Sβ0to enable informed joint decision‐ There should be an on‐going discussion between provider and patient (1B)
- In infants with SS/Sβ0aged 9–42 months, offer hydroxycarbamide regardless of clinical severity to reduce sickle cell complications (pain, dactylitis, acute chest syndrome (ACS), anemia (1A)
- In children aged >42 months, adolescents and adults with SS/Sβ0, offer treatment with hydroxycarbamide in view of the impact on the reduction of mortality (1B)
- In adults and children with SS/Sβ0who have 3 or more sickle cell‐associated moderate to severe pain crisis in a 12‐month period, treat with hydroxycarbamide (1A)
- In adults and children with SS/Sβ0who have sickle cell pain that interferes with daily activities and quality of life, treat with hydroxycarbamide (1C)
- In adults and children with SS/Sβ0and, a history of severe and/or recurrent ACS treat with hydroxycarbamide (1A)
- Ongoing informed consent should be confirmed for all patients on hydroxycarbamide, at least at each Annual Review (1D)
- Children who have started regular blood transfusions for abnormal Transcranial Doppler (TCD) can be switched to hydroxycarbamide therapy (with or without venesection) if they have received at least 1 year of regular transfusions and have no magnetic resonance angiography‐defined severe vasculopathy (1A)
- In children who are treated for primary stroke prevention who are changing from regular blood transfusions to hydroxycarbamide therapy, transfusion should be continued until they have reached the maximum tolerated the dose of hydroxycarbamide (1C)
- Children with TCD velocities in the range 170–200 cm/s (conditional risk category) should be treated with hydroxycarbamide therapy to help prevent progression from conditional to abnormal TCD velocity (1B)
- When treating children with conditional TCD velocities with hydroxycarbamide, the dose should be escalated to maximum tolerated dose (1C)
- In children and adults with a previous history of acute ischaemic stroke or infarcts, hydroxycarbamide should be recommended as second-line therapy for secondary stroke prevention when transfusions are contraindicated or unavailable (1B)
- There is insufficient data to advise commencing hydroxycarbamide therapy for primary stroke prevention in adults (1D)
End organ damage
- The potential benefits of hydroxycarbamide in preventing end-organ damage (renal/splenic and retinopathy) should be discussed with all carers of children/patients with SS and Sβ0(1C)
- In patients with sickle nephropathy with persisting proteinuria despite angiotensin‐converting‐enzyme inhibitor/angiotensin receptor blocker therapy, consider the addition of hydroxycarbamide therapy (2C)
- There is insufficient evidence to treat patients with SS/Sβ0with pulmonary hypertension and avascular necrosis with hydroxycarbamide but it should be considered on a case‐by‐case basis (2C)
- In children and adults with chronic hypoxia, recommend treatment with hydroxycarbamide (1C)
- Patients should be counseled that hydroxycarbamide may prevent priapism (2D)
- In children and adults with SS/Sβ0and symptomatic chronic anemia that interferes with daily activities or quality of life, recommend treatment with hydroxycarbamide (1C)
Use in other genotypes
- Hydroxycarbamide therapy should be considered in adults and children with sickle cell disease (SCD) with genotypes other than SS and Sβ0thalassaemia who have recurrent acute pain, acute chest syndrome or episodes of hospitalization (2C)
- Hydroxycarbamide therapy should be considered in adults and children with SCD with genotypes other than SS and Sβ0thalassaemia for other indications on a case‐by‐case basis (2D)
Concerns of hydroxycarbamide
- Post‐pubertal male patients should be considered for sperm analysis and cryopreservation prior to starting treatment with hydroxycarbamide (1C)
- Consider stopping hydroxycarbamide pre‐conception in male and female patients and in pregnant women (1C) if the patient is not at high risk of serious complications relating to sickle cell disease
- Prenatally and during pregnancy, consider a transfusion programme if there is a severe clinical phenotype as an alternative to hydroxycarbamide treatment. (1C)
- Contraception is advised for patients on hydroxycarbamide (1C)
Dosing and monitoring
Please click on the link below for dosage recommendations
The randomized controlled Multicenter Study of Hydroxyurea (MSH) study showed that treatment with hydroxycarbamide could decrease episodes of pain and acute chest syndrome (ACS) and reduce the need for transfusion. It is hoped that these recommendations shall enable health professionals to provide knowledgeable pain-management support for people with SCD.
The guideline was published in the British Journal of Hematology.
To read the full guideline click on the link: https://doi.org/10.1111/bjh.15235