FDA, the Food and Drug Administration has given its approval to Shire for the marketing of the drug, Intuniv, which is a nonstimulant treatment for attention-deficit hyperactivity disorder in children and adolescents between 6-17 years of age.

It is a once daily drug formulation in the form of an extended release tablet containing guanfacine. The drug works by engaging receptors in the prefrontal cortex which is a part of the brain that has been linked in preclinical research to ADHD.

As many as 4.4 million children between the ages 4-17 have been diagnosed with ADHD at some point in their lives in the United States. According to the Centers for Disease Control and Prevention this disorder is also estimated to effect 4.4 percent of U.S. adults aged 18 to 44.

Intuniv is not a controlled substance and "has no known potential for abuse or dependence," Shire said.

Some side effects that were observed during clinical trials of Intuniv include tiredness, abdominal pain, dizziness, a drop in blood pressure, dry mouth and constipation, Shire said.