I think it's common to occur especially if you stay up a few nights...even one night plus coke's slight hallucinogenic effect mixed with sleep deprivation. I haven't done coke but i've done tons of speed and after 1 night staying up, by 2:00am the next night I was seeing a small size black and white tasmanian devil cartoon become animated and start dancing...so to answer you question, yes, very much so, especialy auditory hallucinations such as mumbled voices trought the walls or hearing people in the forest behind your house in the middle of the night talking about how they're going to kill you and then you running in your house trying to figure out how much time you got until the power goes off and you hear footsteps outside your windows but your afraid to turn on a flashlight because they might see it, so your fucked cuz all the neighbours are sleeping and so are your parents and your arms are purle, your eyes are wide open with black bags underneath and greenish pale face so no one will belive you. Now your getting thirsty but are afraid to turn the sink on and you got to piss but are afraid of the noise it makes and you just wait for the power to go off and at every single damn creak and noise you hear, your heart jumps to a heart attack rate...