What is the general consensus on adding intuniv to my child's stimulant for under-controlled ADHD symptoms?

Could help ,but..... Before adding a second med, or a cocktail of meds, please make sure that the diagnosis is revisited, the child receives a proper dose, and there are not other coexisitng factors affecting the therapeutic response.
It may help... Intuniv (extended release) is generically (guanfacine) available for a long time so this med has been in use for quite some time now...It can be helpful for some with hyperactivity but not great for attention focusing problem. Thus, an adjunct treatment is often added if the stimulant is not adequately controlling the hyperactivity part of the illness. Follow-up regularly! good luck.
Maximize stimulent. Before adding another medication, have your prescriber adjust the dose of stimulant to give the best result without causing dose related side effects. The major benefit of Intuniv is to deal with anxiety that accompanies ADHD in some children, so maximize the benefit of stimulant first.