I also was told by my cardio to "take an extra 25 or 50!" When I worked on the unit we increased and decreased by 25 or 50 or MORE all the time. I have decreased from 100 down to 25. I also went totally off them for about 3 weeks after being on them for 20 years. My heart rate went up too easily, but other than that, nothing else happened. So I went back on 25. I think I may go off again for a bit. Then my heart will think it died and went to heaven when I start them again. lol
When you speak to your doctor ask him what he thinks (or she). I only take a 1/4 tablet of metoprolol and that works fine, but I started on 1/2 tablet. That may not sound like much, but I have low BP and a fainting disorder, so the 1/2 tablet nearly zombified me. My cardio has given me permission to add or take away 1/4 tablet on an as needed basis, and I know several others are on an as needed regimine as well. Dropping your prescription by 1/4 tablet shouldn't be a problem, but surely check with your doctor first.
Good luck.