From what I think I remember being told, is that you can take that many packets in a row, but there have been very few trials to suggest it's completely safe & they do advise against you doing it.
You should be fine, but it's definitely not advisable & never 100% safe, though I am SURE there's thousands of people who've done this, similar, or for even longer, and had no problems.
If you can avoid doing it, do, though.
If you're really worried, then why not ring up your doctor & just see what the think? They're unlikely to advise it, but might tell you how okay it actually is.