What Causes Swelling And Discoloration In The Area Of Taking Claxane Injection?

my wife had premature baby in 2013 at 28weeks. doctor said to use claxane 40mg and 75mg aspirina and 5mg folic acid during next preganancy but only problem is claxane injections as injected part gets dark green colour about an inch and swelling. any alternative as we would like to avoid all side effects on my wife on assumption that it might help her during next pregnancy. Chintan Patel