Arginine Therapy for the Treatment of Pain in Children With Sickle Cell Disease

Inclusion Criteria:

* Established diagnosis of sickle cell disease--Hemoglobin SS (Hb-SS) or Sβᴼ-thalassemia
* 7-21 years of age
* Weight \>= 25kg (55lbs)
* Pain requiring medical care in an acute care setting (emergency department (ED), hospital ward, day hospital, clinic) requiring parenteral opioids, not attributable to non-sickle cell causes.

Exclusion Criteria:

* Decision to discharge home from acute care setting.
* Diagnosis of sickle cell disease with any of the following types: hemoglobin SC disease (HbSC), hemoglobin beta thalassemia (Hb-Beta Thal), hemoglobin SD disease (HbSD), hemoglobin SE disease (HbSE), hemoglobin SO disease (HbSO), hemoglobin AS carrier (Hb AS)
* Hemoglobin less than 5 gm/dL
* Immediate Red cell transfusion anticipated
* Renal dysfunction: Creatinine \>1.0 or 2 x baseline
* Mental status or neurological changes
* Acute stroke or clinical concern for stroke
* Pregnancy
* Allergy to arginine
* Previous hospitalization \< 7 days
* Use of inhaled nitric oxide, sildenafil or arginine within the last 14 days
* Not an appropriate candidate in the investigator's judgement