Codeine is a narcotic (think of heroin which is a narcotic) and will show up as so on a blood test. It also depends what kind of sleeping pill, for example, if you take ativan or xanax for sleep it will show as a benzodiazipine but if it is over the counter it shouldn't. Note, also medications containing Pseudoephedrine can also cause a positive drug test (similar to that of a meth. user). AND PLEASE DON'T MIX WHAT YOU ARE MIXING, IT COULD PROVE DEADLY!!!!!!!!!!!!!!!!!
Bella
PS: I do believe the cough syrup stays in your system for 48-72 hrs.