Patient description: The patient is a 34-year-old African American man with the known history of Sickle cell disease comes to the clinic with severe bone pain. The patient had severe pain in his lower back that radiated to both thighs scored 9 out of 10. The patient has had positive history of sickle cell crises since childhood. He also had the same symptoms in past two weeks treated with oxycodone which was not beneficial to his pain. His PCP sent him to the emergency department to receive intra venous pain modulators. The patient is afebrile within the normal blood pressure. No splenomegaly was detected in the physical exam. He has no positive history of drug allergy. He won't smoke or uses any illicit drugs. The lab study is as bellow: Hgb: 8 g/dl WBC: 10000 /mm3 Plt: 300000 /ml MCV: 106 fL Hemoglobine electrophoresis: 91% HbS 6%HbF 3%HbA2 AST: 22 U/L ALT: 43 U/L Alk P: 53 U/L Ferritin: 1200 ng/ml

Clinical trial eligibility criteria: eligible ages (years): 18.0-55.0,  Anaemia AST, ALT, alkaline phosphatase and bilirubin > 1.5xULN (isolated bilirubin >1.5xULN is acceptable if bilirubin is fractionated and direct bilirubin <35%) Healthy as determined by a responsible and experienced physician, based on a medical evaluation including medical history, physical examination, laboratory tests and cardiac monitoring. A subject with a clinical abnormality or laboratory parameters outside the reference range for the population being studied may be included only if the Investigator and the GSK Medical Monitor agree that the finding is unlikely to introduce additional risk factors and will not interfere with the study procedures Male or female between 18 and 55 years of age inclusive, at the time of signing the informed consent A female subject is eligible to participate if she is of:Non-childbearing potential defined as pre-menopausal females with a documented tubal ligation or hysterectomy; or postmenopausal defined as 12 months of spontaneous amenorrhea [in questionable cases a blood sample with simultaneous follicle stimulating hormone (FSH) > 40 MlU/ml and estradiol < 40 pg/ml (<140 pmol/L) is confirmatory]. Females on hormone replacement therapy (HRT) and whose menopausal status is in doubt will be required to use one of the contraception methods in Section 8.1 if they wish to continue their HRT during the study. Otherwise, they must discontinue HRT to allow confirmation of post-menopausal status prior to study enrollment. For most forms of HRT, at least 2-4 weeks should elapse between the cessation of therapy and the blood draw; this interval depends on the type and dosage of HRT. Following confirmation of their post-menopausal status, they can resume use of HRT during the study without use of a contraceptive method Male subjects must agree to use one of the contraception methods listed in Section 8.1. This criterion must be followed from the time of the first dose of study medication until 5 terminal half-lives post-last dose Body weight < 50 kg and BMI within the range 19 9 kg/m2 (inclusive) Capable of giving written informed consent, which includes compliance with the requirements and restrictions listed in the consent form QTcB or QTcF < 450 msec; or QTc < 480 msec in subjects with Bundle Branch Block  A positive pre-study Hepatitis B surface antigen or positive Hepatitis C antibody result within 3 months of screening Current or chronic history of liver disease, or known hepatic or biliary abnormalities (with the exception of Gilbert's syndrome or asymptomatic gallstones) The values of hematological parameters at screening are: Any values outside the reference range A positive pre-study drug/alcohol screen. A minimum list of drugs that will be screened for amphetamines, barbiturates, cocaine, opiates, cannabinoids and benzodiazepines The values of the following tests at screening are: Serum ferritin: outside the reference range A positive test for HIV antibody Clinically significant CPK >3 X ULN or deemed clinically significant by the investigator Calculated creatinine clearance: < 80 mL/min Subjects with a pre-exisisting condition interfering with normal gastrointestinal anatomy or motility, and/or hepatic function-that could interfere with the absorption, metabolism, and/or excretion of the study drugs. Examples of conditions that could interfere with normal gastriointestinal anatomy or motility cholecystectomy, vagotomy, malabsorption, Crohn's disease, ulcerative colitis, or celiac sprue History of regular alcohol consumption within 6 months of the study defined as: an average weekly intake of >21 units for males or >14 units for females. One unit is equivalent to 8 g of alcohol: a half-pint (~240 ml) of beer, 1 glass (125 ml) of wine or 1 (25 ml) measure of spirits