Differential Diagnosis for a 55-year-old Woman with Nausea, Vomiting, and Elevated Liver Enzymes on First-line TB Drugs

• Single most likely diagnosis:
  • Drug-Induced Liver Injury (DILI): Given the patient's recent initiation of first-line TB drugs (which are known hepatotoxins) and the presentation of nausea, vomiting, along with elevated liver enzymes (SGOT 65, SGPT 59), DILI is a highly plausible diagnosis. The timeline of one month on TB drugs also fits with the typical onset of DILI.
• Other Likely diagnoses:
  • Viral Hepatitis: Although less likely given the context of recent TB drug initiation, viral hepatitis (e.g., hepatitis A, B, C, E) could cause similar symptoms and liver enzyme elevations. However, the absence of other symptoms like jaundice and the specific context of TB treatment makes this less likely.
  • Gastroenteritis: Could cause nausea and vomiting but would less commonly result in significant elevations in liver enzymes.
• Do Not Miss diagnoses:
  • Acute Hepatic Failure: Although the liver enzymes are elevated, if the patient shows signs of hepatic failure (e.g., coagulopathy, encephalopathy), this would be a critical diagnosis not to miss. The current hemoglobin and normal platelet and leucocyte counts do not strongly suggest hepatic failure, but monitoring and further evaluation are necessary.
  • Pyogenic Liver Abscess: Especially in a patient with TB, an abscess could form in the liver, causing fever, nausea, vomiting, and elevated liver enzymes. This diagnosis would require immediate intervention.
• Rare diagnoses:
  • Autoimmune Hepatitis: An autoimmune reaction could cause liver inflammation and elevated enzymes, but this would be less directly related to the initiation of TB drugs and might require additional autoimmune markers for diagnosis.
  • Wilson's Disease: A genetic disorder leading to copper accumulation in the liver, which could cause liver enzyme elevations. However, this would be unusual to present for the first time at the age of 55 and without a prior diagnosis.

Given the information, the most prudent step would be to stop the anti-TB drugs temporarily until the cause of the liver enzyme elevation is clarified, as DILI is a significant concern. Further diagnostic workup, including viral hepatitis serologies, autoimmune markers, and possibly a liver ultrasound, would be necessary to rule out other causes. Reintroduction of TB drugs or substitution with alternative regimens could be considered based on the diagnosis and the patient's clinical response.