My friend was pulled over for a dui and also had prescription pills with an outdated prescription, does this change the charges?

It would seem that if your friend had a prescription for the pills, that the prosecution would not file any additional charges. If the prescription is so old as to suggest the pills your friend had were not the original pills, it could present a problem. I wouldn't be able to tell you how the prosecution would prove the age of the pills though.

It should not change the charge. Get an attorney . The age of the pills in the bottle could present some issues.

Get an attorney. If the prescription is in the same friend's name, then it shouldn't change the charge, simply because they're old/expired. But, if the expired pills are not his, that could be a problem. Best consult an experienced, local attorney right away. Good luck.