Can you take Tylenol pm and percogeaic backache pain relief

According to drugs.com, there are no interactions found in their database between Percogesic [which contains Acetaminophen] and Tylenol PM [which also contains Acetaminophen]

See their webpage here - and consult with your doctor for confirmation and more information.

Why would you take both!

Acetaminophen, despite being OTC, is not to be taken lightly, because it is bad for the kidneys.
So is magnesium salicylate, which is what Percogesic Backache is.
(It is NOT the same ingredient as regular Percogesic, NOT acetaminophen. It is more like aspirin. I for one cannot take aspirin. For some people, the blood thinning aspect is good; for me it isn't. So READ all the precautions on the manufacturer's websites!)

I take Tylenol and ibuprofin together, 2 entirely different pain relievers. Each has slightly different effects which vary from person to person.
I always take the lowest amount I think I can take while still getting some relief, because for me, it's going to be for the rest of my life.
Do doctors know much about OTC drugs? Not nearly as many as should!
Be an informed consumer. Never take a drug without reading all about it. Google each one directly.

Your best bet is to live in a medical marijuana state. Cannabis oils are the BEST pain relievers in the world, and do no damage to your health! There is virtually no pill that is harmless in some way.
Most nights, I eat a tiny bit of candy or cookie with about 5mg of THC and CBD oils in it.
If I could get it legally, I'd probably do that 3 times a day. The effect works for about 8 hours.