What is the best medication to treat high blood pressure?

Depends: There are a lot of factors that affect what medicine should be given first. Race, whether you have diabetes, your age, and how high the blood pressure is would all be factors. Since many patients end up needing two or more medications, it often becomes a mute point which to start with. A thiazide diuretic, ace inhibitor, or arb are good choices for a starting medication.

No such thing: No such thing as the "best " medicine. Each medicine has its positives and negatives. You really have to individualize therapy.