Drug Interactions Between Dolutegravir and Escalating Doses of Rifampicin

Inclusion Criteria: * Ability to give informed consent prior to participation * Willing and able to comply with all study requirements * Receiving standard doses of RIF and INH * HIV antibody negative * Male or non-pregnant, non-breastfeeding female * Study participation will not extend length of ATT by more than 4 weeks Exclusion Criteria: * \< 18 years * Body weight \< 50 kg * eGFR \< 60 mL/min * Abnormal LFTs including ALT \> 2.5 ULN * HIV antibody positive * Non-standard TB regimen (containing RHZE) * Women of childbearing age unless using effective contraception * Family history of sudden cardiac death * Prior history of cardiac disease that precludes the use of low dose digoxin * Medical or psychiatric condition that might affect participation in the study based on investigator judgement * Regular consumption of grapefruit or grapefruit juice * ECG abnormalities that preclude the use of low dose digoxin (intermittent complete heart block, second degree AV block, supraventricular arrhythmia associated with conducting pathways, ventricular tachycardia or fibrillation)