Marc, NAC is used now in plce of amoxicillin, which used to be used at Vanderbilt, but now NAC tends to be used instead. David never prescribed amoxicillin over here because he liked to use as few antibiotics as possible. He thought that NAC would be more than a good substitute and help keep the bowel flora more intact. You do need really to take a macrolide along with doxycycline as they both work synergically, plus it avoids the possible build up of resistance. Azithromycin or roxithromycin are the macrolides of choice as both have good CNS penetration.
Flagyl is definitely a bridge to cross when you get there, so don't rush at it! Have you read this?: