Clonidine, an alpha-2 adrenergic agonist, has been used to treat Tourette syndrome (TS) for nearly 3 decades. This first-tier medication is especially recommended for children and adolescents with a combination of attention-deficit/hyperactivity disorder and mild tics. Although clonidine is thought to have a low rate of adverse effects (AEs), little is known about its tolerability profile in adult patients with TS.
This study investigated the prevalence and characteristics of AEs associated with clonidine through a retrospective chart review. We assessed 36 patients with TS (27 men; mean [SD] age, 24.6 ± 13.9; range, 10–62 years), of whom 32 (88.8%) had comorbid conditions (most common: attention-deficit/hyperactivity disorder, n = 12; obsessive-compulsive disorder, n = 9).
Seventeen patients (47.2%) experienced AEs. Eleven patients (30.5%) withdrew clonidine because of the severity of AE (n = 5) or absence (n = 4)/reduction (n = 2) in efficacy. The most commonly reported AEs were sedation and headache. In most cases, AEs were mild and occurred with higher starting doses. In 12 patients (70.6%) who also took other psychotropic medications, cotherapy could have been linked to the appearance of AE.
Our findings suggest that clonidine is a safe and well-tolerated medication in the TS population. Adults with TS treated with this medication experience mild and relatively infrequent AE; high starting dose and polytherapy seem to be the only clinically relevant risk factors for AE development.