Pharmacokinetics of Lisdexamfetamine (Vyvanse®) in Post-bariatric Surgery Patients

Inclusion Criteria:

1. Male or female subjects.

2. Between the ages of 18 and 60 years at the time of informed consent. *The upper agelimit of 60 has been chosen as this medication carries some cardiovascular risk alongwith the fact that pharmacokinetics in elderly patients vary and may affect thehomogeneity of the study.

3. Must be in good health as determined by physical exam, EKG, and medical history.

4a. Underwent RYGB 9-15 months prior (n=10 study completers) -or-

4b. Have not received bariatric surgery and are matched to the RYGB participants by BMI,age and sex (n= 10 study completers)

5. Women of child bearing potential must be practicing a medically acceptable method ofbirth control and have a negative pregnancy test at baseline.

6. No contraindications to receiving lisdexamfetamine in a single dose of 50 mg.

Exclusion Criteria:

1. Allergy to lisdexamfetamine or any of its constituents.

2. Candidates who are pregnant or nursing.

3. Candidates currently receiving a medication that interacts with lisdexamfetamine,including concurrent use of a stimulant.

4. Subjects who smoke or used any nicotine products in the last six months.

5. Subjects who have a positive urine drug screen for drugs of abuse.

6. Candidates that for any reason cannot comply with the requirements of the studyprocedures.

7. Candidates experiencing clinically significant or unstable neurological, hepatic,renal or cardiovascular disease on laboratory or baseline EKG screening or any medicaldisorder that would put the participant at increased risk in the judgement of theinvestigator or physician.

8. Candidates currently or with a past history of meeting diagnostic criteria forschizophrenia, schizoaffective disorder, bipolar disorder, or other psychotic illness.

9. Candidates with any history of drug abuse or dependence.

10. Candidates with any history of alcohol dependence, or current usage that puts thecandidate at risk in the judgement of the investigator or study physician.

11. Candidates who have participated in an investigational drug study in the past 30 days.

12. Significant iron deficient anemia that may impact the pharmacokinetics oflisdexamfetamine.

13. Participant with a significantly and persistently elevated resting blood pressure (>140/90 mmHg) or pulse (>100 bpm) after repeated measurement.