Adverse effects of therapy
The panel also examined the risks of harm, including weight gain, elevated prolactin levels, sedation, drug-induced movement disorders, hypotension, bradycardia, and ECG changes with medical treatments, compared with placebo or other active interventions. In regard to weight gain, the panel concluded with moderate confidence that people with tics receiving risperidone or aripiprazole (children only) are probably more likely to gain weight than people receiving placebo. There was low confidence for associations between specific therapies and elevated prolactin levels.
Compared with people receiving placebo, there was moderate confidence that tiapride is probably associated with higher rates of physical tiredness and sleep disturbances (children only), that clonidine is probably associated with sedation, and that guanfacine is probably associated with drowsiness (children only). There was moderate evidence that pimozide is probably associated with extrapyramidal symptoms. There was low confidence that any specific treatment led to hypotension, bradycardia, or ECG changes.
Additional guideline specifics
The guideline’s practice recommendations include explaining the natural history of tic disorders to patients and caregivers and evaluating patients for functional impairment. Watchful waiting is an acceptable approach in people who do not experience functional impairment, and patients receiving medications for tics must have periodic reevaluations for the need for ongoing medical treatment. People with Tourette syndrome should be referred to resources for psychoeducation for teachers and peers, such as the Tourette Association of America.
Comorbid ADHD occurs in 30%-50% of patients with tics. If screening for ADHD is positive, the burden of ADHD symptoms should be assessed and those with functionally impairing ADHD should be treated for the disorder. Similarly, obsessive-compulsive behaviors occur in 10%-50% of those with Tourette syndrome. If an assessment finds comorbid obsessive-compulsive disorder, it should be treated.
Other psychiatric comorbidities with Tourette syndrome include anxiety disorders, oppositional defiant disorder, and mood disorders. When screening for these conditions, one must inquire about suicidal thoughts and suicide attempts and refer to appropriate resources if present, according to the guidelines.
Individuals with tics and comorbid ADHD should be advised that alpha2-adrenergic agonists may provide benefit for both conditions. Alpha2-adrenergic agonists should be prescribed for the treatment of tics when the benefits of treatment outweigh the risks and patients must be counseled regarding common side effects of alpha2-adrenergic agonists, including sedation. Heart rate and blood pressure must be monitored in patients with tics treated with alpha2-adrenergic agonists. If prescribing extended-release guanfacine, one must monitor the QTc interval in patients with a history of cardiac conditions, patients taking other QT-prolonging agents, or patients with a family history of long QT syndrome. If discontinuing alpha2-adrenergic agonists, they must gradually be tapered to avoid rebound hypertension.
If considering antipsychotic therapies, patients must be counseled on the relative risk for extrapyramidal, hormonal, and metabolic adverse effects to inform decision making on which antipsychotic should be prescribed. Before prescribing antipsychotics for tics, ECGs must be performed. The QTc interval must be measured before and after starting pimozide or ziprasidone, or if antipsychotics are coadministered with other drugs that can prolong the QT interval. The lowest effective dose should be prescribed to decrease the risk of adverse effects, and patients should be monitored for drug-induced movement disorders and for metabolic and hormonal adverse effects of antipsychotics. When attempting to discontinue antipsychotics for tics, the medications should be gradually tapered over weeks to months to avoid withdrawal dyskinesias.
If topiramate is prescribed, patients must be counseled regarding common adverse effects, including cognitive and language problems, somnolence, weight loss, and an increased risk of renal stones.
Some patients with Tourette syndrome use cannabis as a self-medication for tics and comorbidities. Because of the risks associated with cannabis use and widespread self-medication with cannabis for tics, where regional legislation and resources allow, physicians must offer to direct patients to appropriate medical supervision when cannabis is used as self-medication for tics. Appropriate medical supervision would entail education and monitoring for efficacy and adverse effects, according to the guidelines.
Where regional legislation allows, physicians prescribing cannabis-based medication must prescribe the lowest effective dose to decrease the risk of adverse effects. Physicians prescribing cannabis-based medication must inform patients that medication may impair driving ability. Physicians prescribing cannabis-based medication to patients with Tourette syndrome must periodically reevaluate the need for ongoing treatment.
A multidisciplinary evaluation is needed to establish when the benefits of treatment outweigh the risks for prescribing DBS for medication-resistant motor and phonic tics. The DSM-5 diagnosis of Tourette syndrome must be confirmed and exclude secondary and functional tic-like movements when considering DBS for medication-resistant tics. A mental health professional must screen patients preoperatively and follow patients postoperatively for psychiatric disorders that may impede the long-term success of the therapy. Physicians must confirm that multiple classes of medication (antipsychotics, dopamine depleters, alpha1 agonists) and behavioral therapy have been administered (or are contraindicated) before prescribing DBS for tics.
The practice guideline was developed with financial support from AAN. Dr. Pringsheim reported no disclosures. Dr. Piacentini reported receiving funding for travel and speaking from foundations and universities and has received royalties from publishers. In addition, he has performed behavior therapy for tics for approximately 50% of his clinical time and has received financial or material support from Pfizer, the National Institute of Mental Health, and foundations.
SOURCE: Pringsheim T et al. Neurology. 2019 May 6. doi: 10.1212/WNL.0000000000007466.