Your pdoc has prescribed this med as they believe that it's best for you at this time.

I'm not surprised you seem somewhat curious.

One thing I've learnt is different countries have different meds that are approved for various symptoms and even within each country it can be different. For instance, I'm on Lamatrogine here in Australia but it's not approved for bp treatment but in other countries it is.

You have every right to ask your pdoc all about this med and why specifically it has been prescribed for you.