Summary
Clonidine and clonidine extended-release have been shown to have efficacy in the treatment of ADHD. However, the studies contain significant flaws. Patients with ADHD, especially those with comorbidities, require individualized treatment. Clonidine may be efficacious, and is worth trying in patients as monotherapy or as combination therapy.
Improvement in inattention, impulsivity, and hyperactivity has been reported. No additional benefit in improvement of ADHD symptoms was noted with higher doses of clonidine or clonidine extended-release. It is not evident whether clonidine extended-release is better than clonidine in regards to efficacy and safety. Clonidine and clonidine extended-release provide additional benefit in improving ADHD symptoms as add-on therapy with psychostimulants. Optimal dosages of clonidine or clonidine extended-release require individualization, whether they are used as monotherapy or in combination with stimulants.
In general, both clonidine and clonidine extended-release were well tolerated. Clonidine was better tolerated in divided doses. The most common side effects were somnolence, fatigue, bradycardia, and hypotension. Electrocardiographic changes were clinically insignificant. However, serious cardiac side effects can occur, especially in individuals with other risk factors. Future studies investigating the long-term effects and safety of clonidine and clonidine extended-release in the treatment of children with ADHD are needed.