<s>[INST] I have taken 10 mgs of Bystolic before. My G.P has me on 10 mgs twice daily. I tried metrpolol once per day for the past 6 months but my B.P went up to 149/89. My g.p. has advised me to go back to twice daily. How long will it take to reduce my B.P by increasing my dosage? [/INST] Thanks for contacting HCM. Metoprolol is not a very strong antihypertensive. You should have continued it twice daily. Now get your BP checked regularly as to whether BP is coming down, it should stabilize in 2-3 days, if not then your doctor may have to change the medicine. Regards </s>