cabbage juice ?

my dad just got released from the hospital after they
cortiorized (can't spell) his ulcer.

I recommended he start drinking cabbage juice ASAP

They did give him some drugs to take, and I just wanna make
sure that the drugs they are prescribing doesn't interfere
or cause a bad reaction with the cabbage juice

I'm always alittle worried when telling someone to take some natural or food medication that it will interfere with a drug
prescribed by the doctor & create a bad reaction

Anyone ever have a problem with cabbage juice

thanks so much