It's not blood pressure medication, it is anti-coagulation medication. It is dangerous as it can cause uncontrollable bleeding - the blood can't clot - and there is no antidote. Thus it can only be used under close medical supervision.
Caller says they are from Legal Assistance Helpline for Xarelto Claims, won't answer any other questions about who they are (sounds like Sweatshop call staion in background) probably International call using VOIP to imitate local call. Caller ID said out of are even though it was 540 area code.. A sure sign of a SCAM