hi sir,i’m happy to see your care and concern for your wife.phospha 250 neutral and peters are not at all the same.phospha is phosphorus supplementation where as pexeva is paroxetine which is an anti depressant drug.both are in no way related to each other.once talk to your doctor before starting or stopping pexeva.moreover,as she had a kidney transplant,you need to be more careful with medicines.importance of consultation with a specialist before medicine administration can be over looked.hope my answer clarifies your doubt.any further queries,please let me know.i’m always there to guide you.thank you.wish you and your family a very happy,healthy,peaceful new year 2018.wish your wife a speedy and complete recovery.thank you.take care.bye.