Facebook Twitter Email Print Expert Advice Can pummelos and grapefruit have drug interactions? Answer The pummelo, also known as shaddock, is a cross between a grapefruit and an orange and therefore contains same compounds as grapefruit. Both grapefruit and pummelo are fruits that block an enzyme in the liver that breaks down many medications. Blocking this enzyme means there will be higher levels of circulating medicine in the body which can be dangerous. Talk with your doctor, pharmacist, or health care professional to see if you can consume grapefruit, pummelo (and their juice) with your medicine.