Safety and Tolerability of Metformin in People With Tuberculosis (TB) and Human Immunodeficiency Virus (HIV)

Inclusion Criteria:

1. Age 18 through 65 years.

2. HIV-1 seropositive status prior to or after screening.

3. Chest radiograph compatible with pulmonary TB.

4. Positive sputum Xpert MTB/RIF or pert MTB/RIF Ultra with one cycle threshold (Ct) <25 or subsequent culture confirmation.

5. RIF susceptibility diagnosed by an approved TB diagnostic test e.g. Xpert MTB/RIF (Cepheid), Xpert MTB/RIF Ultra (Cepheid) or BD MAX (Becton-Dickinson).

6. Residence within study catchment area.

7. If female of childbearing potential, willing to use contraception for the durationof study participation (Criteria for childbearing potential and for acceptablecontraception). If male, willing to use condoms for the duration of metformintreatment plus 3 months after stopping metformin.

8. Able and willing to provide informed consent.

Exclusion criteria:

1. Any condition for which participation in the trial, as judged by the investigator,could compromise the well-being of the participant or prevent, limit or confoundprotocol-specified assessments.

2. Is critically ill, and in the judgment of the investigator has a diagnosis likely toresult in death during the trial or the follow-up period.

3. TB meningitis or other forms of severe TB with high risk of a poor outcome as judgedby the investigator.

4. Pregnant or breastfeeding.

5. Resistance to any first-line ATT drug demonstrated by susceptibility testing.

6. More than 14 days ATT for the current episode of TB, prior to enrollment.

7. Taking any fluoroquinolone antibiotic.

8. History of diabetes mellitus or fasting blood glucose >7.0 mmol/L on screeningevaluation.

9. History of congestive heart failure, chronic liver disease, diabetes, autoimmunedisease or malignancy.

10. Consumption of >28 units (men) OR >21 units (women) of alcohol/week.

11. Use of metformin within 1 year prior to enrollment.

12. History of sensitivity to metformin.

13. Acute or chronic metabolic acidosis based on reported medical history or laboratorytests performed on screening.

14. Body mass index (BMI) <17kg/m^2 on screening evaluation.

15. Peripheral blood CD4 T cell count <50 cells/mm^3 on screening evaluation.

16. Hemoglobin <9 g/dL for males, and <8 g/dL (women) for females on screeningevaluation.

17. Platelet count <50,000/mm3 on screening evaluation.

18. Absolute neutrophil count <750 cells/mm^3 on screening evaluation.

19. Estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m^2 calculated by theChronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.

20. Serum bicarbonate <18 mmol/L on screening evaluation.

21. Aspartate Aminotransferase (AST) or Alanine Aminotransferase (ALT) ≥3 times theupper limit of normal (ULN) on screening evaluation.

22. Hepatitis B surface antigen positive.

23. Enrollment in another interventional study at any time during participation in theMETHOD trial.

24. Imprisonment at the time of or after enrollment in the METHOD trial.

25. Diagnosis of active Coronavirus Disease 2019 (COVID-19) at the time of screening orhigh suspicion of active COVID-19 disease during screening.