The name of the interrupt is "pin change". It is not as simple as the interrupt pins but not too difficult.
Why would an I2C device use up interrupt pins? (I haven't checked but I dont think any analog or I2C pin is also a digital interrupt.)
Yes I2C uses interrupts (for slaves) but that doesn't use up the pins.
Some I2C devices like the ADXL345 do have output pins which are called interrupts but you can put them to regular pins and read them with digitalRead().