METPURE is a beta blocker
group of drug having metoprolol
as its salt.
The known side effects of beta blockers are hypotension
etc.However no untoward side effects take place if used for very long time.
You may have to continue this drug life long since your blood pressure is under control because of the action of this medicines.Once the drug is taken off,you may have rebound increase in blood pressure.
There is no need to stop the medicines as you are doing comfortable with this.
As far as pranayama is concerned,it is very good and you continue doing it because it definitely helps in keeping your cardiovascular system relaxed and at least it may help in keeping your blood pressure controlled on this small dose.