How heaps panadol does it bear to overdose on?
Answer: Many. The dosage which is recommended can actually be doubled pretty undamagingly (depending on your weight/height/age) but don't do it.
Overdosing on panadol will probably make you blind and drastically uncomfortable, and may pass you liver problems. I don't know why you're asking, but don't try it. Panadol is sold in pack of 12 to discourage people from overdosing intentionally.