Contact the company that supplies the lines.. Check and see if the line comes with an insert information section. There is a resent post about this very thing.. Mostly from what I have read, you prime the line with what ever med it is being used for and label that line for only that medication. Flushing with NS is not recommended because it causes tissue irritation.. If you are using one line for two medications, that is against most manufacturers guidelines. This is not a portacath, IV or central line of any kind... It is a SQ port similar to implanted insulin devices. Only small amounts are to be injected at a time correct ?