It depends on a lot of things, most especially your physical health. How long have you been taking kratom, are you addicted, etc. Early on during my 2 year kratom binge I could do 200mg DXM with 5g of 15x standardized with no problems whatsoever (in all truth it was the most powerful legal high I'd ever experienced.)
But, as my addiction grew to the 30-40g of ground leaf/day, things changed. On a whim I downed 190 mg of SymptomPak DXM and downed kratom as usual. It was a good, restless 24 hour trip and led me to finally ask a girl out who eventually became my girlfriend and saved me yadda yadda yadda. But severe chest tightness soon took over. I went to the doctor and they said it was asthmatic bronchitis. They gave me albuterol, prednisone, and tramadol and all was well after a couple days. You might ask, "well what about the anxiety about the budding relationship, couldn't that have caused it?"
A later experience would mostly invalidate the idea. I took ~200mg with my girlfriend and downed K powder throughout (I had to). The trip was great but soon after some serious respiratory issues started to manifest: difficulty breathing, wheezing, chest pain. Went to ER, they put me on a bed and let me writhe in AGONY from withdrawal for 8 hours. I was okay afterwards, but never risked combining dxm and k again.
My advice is simple, don't do it if your body is weakened in some way. Any kind of long term addiction counts. Both DXM and Kratom are opioids, so they can cause additive respiratory depression (and possibly death in mammoth doses) so just be careful.