"Even though there are more reasons than ever for those with chronic Hepatitis C to have a daily glass of grapefruit juice, there is a catch. Unfortunately, there is a long list of medications that can be dangerous when combined with this fruit."
http://www.hepatitis-central.com/mt/archives/2008/02/what_you_need_t.html
http://www.medhelp.org/posts/Hepatitis-C/Opinions-on-the-Grapefruit-Juice-Theory/show/489529
Be careful of medication interactions, see following:
http://hepatitiscnewdrugs.blogspot.com/2011/01/grapefruit-juice-dangerous-medication.html
You can google yourself to find further reading.