Small white round kind of thick with k 3 on one side and cross on other?

Dont know the true owner

Promethazine HCl 25mg

https://www.drugs.com/promethazine.html

Promethazine is used to treat allergy symptoms such as itching, runny nose, sneezing, itchy or watery eyes, hives, and itchy skin rashes.

Promethazine also prevents motion sickness, and treats nausea and vomiting or pain after surgery. It is also used as a sedative or sleep aid.