First I'd like to find out the side effects and potential health risks. Is it one that can lead to TD? I did a wikipedia entry and didn't see that listed, but I saw fatigue and potential effects on blood pressure be a potential bother.
If it doesn't have adverse reactions, it may be useful. I'm a bit concerned on the blood pressure part. For me, I have normal to low blood pressure, so dropping it lower probably isn't a good thing. For someone who has high blood pressure, then this med may be more okay to use.
I think when considering meds, make sure to reearch, find out the side effects and weigh out the pros and cons.
My son was on Tenex for awhile - it does the same thing. It helps control the impulsiveness - does noting for attentiveness. It is sometimes used for ADHD. We thought it was helpful. Since it isn't psychotropic we didn't see any strange behaviors.