Well all I can say is..anytime I do Salvia I only do the highest dosage. Ontop of that I've had an Oxy habbit for 5+ years and I do them together. They don't seem to affect the others high. if anything the oxys just secure that you have a more euphoric feeling.
So not sure what dose of Salvia your doing and how it effects you, so take that into consideration. But again I only do the highest dosage of salvia and I did 160mg of oxys in my system too. So take as a grain of salt and let me know how you do. Or if you have follow up questions, please ask away b4 trying anything.