I spoke to my GP about the sweet taste in my mouth issue.
I had done a complete blood work at the hospital a week before, so she checked the results on the computer. All normal.
She then did a quick blood sugar test and it was low (56). She thinks the sweet taste it's a combination of hypoglycemia and some side effect of the tramadol.
She said I should add more carbs in my meals while Im having the PCS symptoms (my normal diet is low carb for weight management). Also she asked me to have snacks too, specially having something to eat 10 min before taking the tablets.