Optimizing Hydroxyurea Dosage With Pharmakokinetic in Patients Suffering of Moderate to Severe Sickle Cell Anemia

The goal of this study is to evaluate if patients with sickle cell disease can achieve a maximum tolerate dose of hydroxuyrea (HU) over a period of 12 months faster with pharmacokinetic testing than the standard of care bloodwork follow-up. Pharmacokinetic test is used to evaluate the process by which drugs are absorbed, distributed in the body, localized in the tissues, and is excreted. Patient will be a randomized (coin toss method) into 2 groups. Group A will have an increase of their HU dosage with pharmacokinetic results and Group B will have an increase of their HU dosage following the standard of care bloodwork follow-up. Group C will include patient with sickle cell disease that has been taking HU for at least 12 months and will undergo a pharmacokinetic dosage to check the level of HU only one time.