NEW YORK — Mylan N.V. and Teva Pharmaceutical Industries Ltd. have released guanfacine extended-release tablets, a nonstimulant medication for attention deficit hyperactivity disorder (ADHD), in the United States.

The pharmaceutical companies said Tuesday that their products, available in strengths of 1 mg, 2 mg, 3 mg and 4 mg, are generic equivalents of Intuniv from Shire.

Guanfacine ER tablets are indicated for the treatment of ADHD, either used alone or as an add-on to stimulant medications.

Intuniv guanfacine ER tablets had U.S. sales of more than $804 million in the 12 months through the end of March, according to IMS Health data reported by Teva and Mylan.

“Guanfacine extended-release tablets join Teva’s current generic line of seven ADHD products,” stated Brendan O’Grady, president and chief executive officer of North America generic medicines for Teva. “We recognize the need to make affordable generic treatment options available to patients with ADHD.”

ADHD is the most common neurobehavioral disorder diagnosed in children in the United States. ADHD affects 1 in 10 U.S. children and half of these children are diagnosed by the age of six.