Is there a difference between ephedrine (ephedrine sulfate) and pseudoephedrine (ephedrine sulfate)?

No: They are very similar drugs. At this time neither one is available in the US.

Different drugs: They are chemically related, but Pseudoephedrine is safer, has fewer side effects (elevated blood pressure, pulse, increased anxiety etc.) and for the most part, pseudoephredrine and phenylephrine have replaced Ephedrine (ephedrine sulfate) in most cold medicines. Ephedrine (ephedrine sulfate) is still around, used in lots of chinese herbal remedies and weight loss drugs. I do not recommend Ephedrine (ephedrine sulfate) for any of my patients.

Not a lot: Same chemical formula, just slight difference in direction of a side chain. But this little difference does give a little bit different effect, or intensity of effect in body. That oh on top, with one it points forward, with the other it points back, thats it.