Question: what are the side effects of the drug ibrutinib?
Answer: Risk of infection. This treatment can reduce the number of white blood cells in your blood. ... 
Anaemia (low number of red blood cells) ... 
Bruising and bleeding. ... 
Diarrhoea. ... 
Constipation. ... 
Feeling sick. ... 
Sore mouth. ... 
Muscle or joint pain.