Tenex and ADHD. Tenex is a drug for high blood pressure which helps the arteries to relax allowing the heart to beat more easily. Basically the drug acts on the prefrontal cortex of the brain and lessens the impact of incoming stimuli, thus helping the patient to focus much better. It has been estimated that up to 30% of children on ADHD psychostimulants have problems with their side effects and therefore Tenex used for ADHD seems to be a valid alternative. . You may see it advertised as Guanfacine or Dipresan in countries outside the USA. If you are trying to figure out how to deal with childrens ADHD, there are places you can look for information. First off, you can try searching the internet to find resources and forums that can help you with your questions. The last thing to make sure you do it work with your doctor to get help.