Study to Confirm the AuthenTicity of Point of Care Urine samplEs Using Oral fluoreScein Sodium in adulTs With substancE Use Disorder (ATTESTED)

Inclusion Criteria: * • Written informed consent, obtained from the person or legally acceptable representative, before any study-related procedure is performed. Adults aged between 18 and 65 years, inclusive, at the time of signing the informed consent form. * A documented current substance use disorder, including but not limited to alcohol, cocaine, and/or opioid. * Female participants must be: Not women of childbearing potential (WOCBP), i.e., postmenopausal and/or surgically sterile, OR: WOCBP who agree to use a contraceptive method that is highly effective (based on the investigator's judgment) for 28 days before and after study product administration. * Male participants must agree to use effective birth control methods and must not donate sperm until 2 weeks after study product administration. * Must agree not to be a gamete donor from Screening until 28 days after the follow-up telephone call. * Willing and able to comply with the study instructions and attend all scheduled study visits. Exclusion Criteria: * Life expectancy less than 5 years. * Women who are pregnant or are breast-feeding. * Known cirrhosis. * Diagnosis of Gilbert's syndrome. * Heart failure, classified as being in New York Heart Association Class II-IV at Screening. * Known allergy to fluorescein, Gatorade™, or any of their excipients. * Estimated glomerular filtration rate \<30 mL/min/1.73m2 using the Cockroft-Gault method at Screening. * Hemoglobin \<120 g/L at Screening. * Diagnosis of sickle cell anemia or sickle cell trait. * Any major episode of infection requiring hospitalization and/or treatment with intravenous antiinfective agents during the 2 months prior to Screening. * Use of fluorescein for medical imaging (eg, angiogram, corneal staining) in the 3 days prior to the Randomization Visit. UP * In the opinion of the investigator, any other condition that would preclude participation in the study.