I have a 26 month old that took a clonidine 0.1mg what should i do or what will happen will he be okay?

Have him checked: I would call his/ her pediatrician or take him to an urgent care. This medicine lowers blood pressure. 0.1 mg is a lower dose for adults. He should have his blood pressure checked. It might make him/her feel lightheaded or dizzy.

See a pediatrician : This is an adult dose of a drug that lowers blood pressure, slows the heart and can have central nervous system effects. It can take several days to clear. The child may need to be watched in a hospital setting.