Is it safe for me to eat grapefruits while I'm taking sertraline and hydrocodone?

No. Grapefruit and grapefruit juice may decrease your body's processing of sertraline and hydrocodone. This means their levels could build up in your body and intensify side effects. Do not combine these medications with grapefruit. Other citrus fruits appear to be safe, though. http://www.medicinenet.com/script/main/art.asp?articlekey=14760.
No. Grapefruit can affect the breakdown of sertaline (zoloft) and could make it ineffective.