can lidocaine2% alter drug test?

Answer 1

only if they are testing for lidocaine. for a narcotic screening test, no.

Answer 2

Both lidocaine and novocaine are cocaine derivatives, so yes. But if you have been given lidocaine as part of medical procedure, such as dental work, just get a letter from the appropriate individual stating how much, when and why. You should be OK with that, as it's then a legitimate use.