Monitor QTc in patients with increased risk.

• Neutropenia

• GI upset

• Prolongation of QTc interval

• Drug interactions

Recommend review of patient medications due to high frequency of significant interactions.

• CYP450 interactions ++
• Other QTc prolonging agents
• Statins - increased rhabdo
• CCBs - hypotension, AKI
• Colchicine - increased bone marrow toxicity
• Increased anticonvulsant levels
• Increased tacrolimus levels

Very high tissue penetration and concentration intracellularly means in vivo activity may not be predicted by in vitro testing.