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

One hundred fourteen eligible persons will be randomized. One hour after completely emptying their bladders, in a blinded manner, half will receive Gatorade and the other half will receive Gatorade with 100 mg of fluorescein. All will then drink 500 ml of water and 15 minutes later they will provide urine samples. A solution of sodium bicarbonate will be added to the samples and blinded observers will then examine all of the samples for fluorescence using a Qbit fluorometer.

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.