Dxm 5 hours after Oxycodone?

Would taking a 350mg 2nd plateau dose of dxm 5 hours after taking 20mg of oxycodone be safe? As for, would the respitory depression from the oxy be gone by 5 hours from taking it or would there be any interaction, i know dxm potentiates opiates but i dont think it would for it being taken so long ago.