Both the medications are likely prescribed to you because of possible prominent anxiety symptoms. But of the two medications, Paroxetine is a SSRI, which will be your primary molecule to curb the anxiety symptoms. Placida is an add on molecule to give quick relief to your symptoms.
Both can be taken, no issues.
Word of caution : don’t go for self dosing
Don’t stop the medication abruptly
May precipitate withdrawal symptoms.
Next Steps
If on treatment symptoms persist, you may consult a psychiatrist for dose adjustments.