It depends on a few things, first and foremost on the gauge of the wire and how long your runs are going to be. Most likely it's pretty thin wire from a HTIB, probably 16 gauge. That's actually OK if the runs are under 10 feet or so. Any longer and I would go with 14 gauge. Longer than 40 feet then that's when you want to think about 12 gauge.
I'd also take a look at the wire itself, if it looks like pure copper then it should be good to go. If you notice any filler in there, usually it's aluminum, then it will probably be worth it to invest in some pure copper stranded wire that's oxygen free.
Jason Hicks
Aperion Audio Guru