If you are using these tires on the street and the hole is not near or on the sidewall you should be fine.

If the hole is near the sidewall or if you run in any type of track events I would just go ahead and get yourself some new tires. I usually try to replace all 4 tires at the same time its pretty ghetto to have tires with various thread wear but Im a snob. If you are running track events I would assume you would be running with R compound and not some wimpy street tires.

I patched my street tires w/o any concerns and like I said Im a snob. I dont do crazy stuff with my car on the street or drive over 100mph.