FYI, Both Tenex and Intuniv have the same active ingredient (guanfacine). However, they act differently from each other, and it is a mistake to consider Intuniv as a simple "long-acting version" of Tenex. The difference has to do with the time-release kinetecs of Intuniv in the body (see article:
http://www.additudemag.com/adhd/article/8177.html).
Our son was on Concerta from age 6-10. In addition to ADHD, he has suffered from mild oral/motor tics. So, he took Tenex to help reduce tics, which were exacerbated by the Concerta stimulant.
At age 10, when Intuniv was introduced, we switched him to Intuniv, discontinued Tenex, and slowly dropped Concerta. We understand it is important to add Intuniv in 1 mg increments, about one week at a time. It really took us about 4 weeks to assess whether Intuniv was helping the ADHD as well as Concerta with respect to hyperactivity, inattention and impulsivity.
Our assessment is that our son has definitely benefited from the elimination of certain side effects from Concerta -- namely, sleeplessness and reduction in appetite. He now sleeps VERY well at night, and eats heartily. His tics seem completely gone.
His hyperactivity is definitely reduced significantly. He is much calmer and more even-keeled. His impulsivity is also noticeably improved versus no medication. Our sense is that Concerta addressed his inattention a bit better. However, on balance -- and considering overall effect and side effects -- we think that Intuniv is the better fit.
IMPORTANT FINAL NOTE: Intuniv is definitely not Tenex. The effect of Intuniv on our son is very different from the dose of Tenex that he had been taking along with Concerta for 3+ years. If you do try Intuniv, consider sticking with it for at least 4 weeks, and remember to titrate up in mg slowly. Sleepiness is the main side effect, but for our son, the sleepiness subsided signficantly after about 4 weeks. It's my understanding that if sleepiness is an obvious and major problem, then you have probably titrated up to quickly in mg, or you should reduce to the next level lower of mg.