Can you take Sudafed and oxycodone together?

Yes you can. It won't harm you as long as you keep to the dosages recommended for each. For chronic users, however, this combo made lead to some insomnia.

Warning: I was taking 10mg oxycodone every 3-4 hours when I took one Sudafed. What ensued was strong anxiety and panic for 4 hours (crying, pacing, feeling crazy), with a recurrence near bedtime. I do not recommend.