What can cause sudden elevation of liver levels in a patient with biliary cirrhosis on meds?

PBC Elevated LFT's: Primary biliary cirrhosis (pbc) itself is a terminal cirrhotic state of liver, requiring liver transplant. There is not much ast & alt enzymes left in liver to go up. Certain insults, can expedite liver damage, by elevated lft's: medicines metabolized by liver, alcohol, an obstruction in porta hepatis, ? Malignancy, need to be considered.