We will conduct a randomized placebo controlled trial to determine whether administration of intravenous (IV) NAC to participants with TB DIH, in dosages similar to that used in paracetamol poisoning, can improve recovery from hepatotoxicity.

South Africa has a huge tuberculosis (TB) disease burden, with 948 per 100 000 people diagnosed with TB in 2008. TB drug induced hepatitis (DIH) is a common adverse effect of TB therapy that causes significant patient morbidity and prolonged hospital stays. N-Acetylcysteine (NAC) has been extensively studied and used for many years in the treatment of paracetamol-induced hepatotoxicity, with good evidence of efficacy and safety. NAC has also been used in other forms of liver injury and drug toxicity. It has not previously been used in the management of TB DIH.

We will screen all patients with clinical hepatitis on TB treatment admitted to New Somerset and Groote Schuur hospitals and aim to recruit 100 participants over 3 years. We will randomise 50 participants to receive an IV loading dose of 150mg/kg of NAC over 60 minutes followed by 50mg/kg IV over 4 hours by continuous infusion and finally 100mg/kg IV over 16 hours. Fifty participants will be randomised to receive placebo. The primary outcome will be time to normalisation of liver function (ALT<100). We will also determine the effect of NAC on duration of hospitalization, rate of recovery from liver failure, all cause mortality, and describe adverse effects of IV NAC in this patient population.

Inclusion Criteria:

• Adults > 18 years old
• Diagnosed with pulmonary or extrapulmonary tuberculosis based on symptoms, radiological features and/or laboratory evidence.
• On first line antituberculous therapy
• Diagnosed with TB DIH

Exclusion Criteria:

• Patients with a diagnosis of acute viral hepatitis based on a positive anti-HAV, IgM, anti- HBcIgM, or confirmed hepatitis C infection
• Patients known to be asthmatic