Tics are sudden, rapid, recurrent, nonrhythmic motor movements or vocalizations. They can include simple movements like eye blinking, facial grimacing, or shoulder shrugging. More complex tics include touching objects, hopping, twirling, or repeating words or phrases. Tics often first appear in childhood between the ages of 5 and 7 and occur more often in boys than girls.
What Causes Tics?
Tics are believed to be caused by abnormalities in the brain circuits that control motor function, specifically in the basal ganglia. The exact mechanisms are not fully understood, but there appears to be hyperactivity and alterations in the dopamine pathways in the brain that result in the uncontrolled motor and vocal tics.
In many cases, the cause is unknown. However, tics can sometimes be triggered or exacerbated by:
- Stress or anxiety
- Fatigue
- Illness
- Excitement
- Certain medications
Tic Disorders
There are several neurological disorders characterized by tics:
- Transient tic disorder – tics last less than one year
- Chronic motor tic disorder – motor tics only lasting more than one year
- Chronic vocal tic disorder – vocal tics only lasting more than one year
- Tourette syndrome – both motor and vocal tics lasting more than one year
Tourette syndrome is the most well known and severe of the tic disorders. It begins in childhood and often improves by adulthood. Along with frequent motor and vocal tics, people with Tourette syndrome may also have behavioral problems like ADHD or OCD.
Can Medications Cause Tics?
In some cases, yes, certain medications can cause tics or worsen existing tics in people prone to tic disorders. However, it is also possible that the underlying condition being treated, rather than the medication itself, is contributing to tics.
Stimulants for ADHD
Stimulants like methylphenidate (Ritalin) and amphetamines (Adderall) are commonly prescribed for conditions like ADHD and narcolepsy. There are some reports that stimulants can trigger the onset or exacerbate tics, particularly in high doses.
However, studies show mixed results. Some demonstrate a worsening of tics in a subset of patients taking stimulants, while others show improvement or no change in tics with stimulant therapy. More research is needed, but it appears the development or worsening of tics in patients taking stimulants is uncommon.
Antidepressants
Antidepressants, like SSRIs and tricyclics, are sometimes associated with new onset tics or worsening of existing tics. However, this side effect appears to be very rare.
In fact, SSRIs like fluoxetine (Prozac) are considered first line treatment options for tic disorders. So for most patients, antidepressants do not appear to cause tics or make them worse. But individual responses can vary.
Antihistamines
First generation antihistamines like diphenhydramine (Benadryl) have been associated with triggering tics. Newer second generation antihistamines like loratadine (Claritin) do not appear to have this effect.
The mechanism by which antihistamines induce tics is unknown. It may be related to their anticholinergic properties. Use of first generation antihistamines should be avoided in patients with tic disorders.
Cocaine
Use of cocaine can cause new onset of transient tics or severely exacerbate existing tics. Cocaine is thought to provoke tics by altering dopamine pathways in the brain that control motor function. Tics induced by cocaine use are temporary and should resolve after the drug is out of the person’s system.
Medications for Parkinson’s Disease
Levodopa and dopamine agonists used to treat Parkinson’s disease have been associated with new onset tics or worsening of tics in some patients. Examples include pramipexole (Mirapex), ropinirole (Requip), bromocriptine (Parlodel), pergolide (Permax).
It is thought these medications overstimulate dopamine receptors, which exacerbates tics in susceptible individuals. However, this side effect is considered rare. For most patients, the benefits of these drugs outweigh the risks.
Other Medications
A few other medications have been occasionally linked to tics, like:
- Chloral hydrate (sedative)
- Metoclopramide (Reglan) – antinausea drug
- Lamotrigine (Lamictal) – seizure/bipolar disorder drug
- Olanzapine (Zyprexa) – antipsychotic
- Isotretinoin (Accutane) – acne drug
However, the evidence associating these medications with tics is limited to isolated case reports. More research is needed to confirm these links.
Who is at Risk for Medication-Induced Tics?
Those who already have a chronic tic disorder like Tourette syndrome are most vulnerable to developing medication-induced tics or having their tics worsened. Underlying genetics and abnormalities in certain brain regions likely increase susceptibility.
Males also appear to be more prone than females to develop tics from medications. This may relate to hormones influencing dopamine pathways in the brain.
Finally, younger children seem to be the most sensitive to medications triggering tics or making them worse. This is likely because the brain regions that control motor function are still developing.
Managing Medication-Induced Tics
If new onset tics or worsening of tics appear after starting a new medication, talk to your doctor. Never abruptly stop a prescribed medication without medical advice.
Your doctor may recommend:
- Lowering the medication dose
- Switching to a different medication in the same class
- Adding a medication to suppress tics, like clonidine (Catapres) or guanfacine (Tenex)
- Trying behavioral therapies like CBIT (Comprehensive Behavioral Intervention for Tics)
In most cases, the benefits of continuing the medication outweigh the risks of the tics. Your doctor can help find the most appropriate treatment plan.
The Bottom Line
Certain medications have been associated with new onset or worsening of tics, particularly in those already diagnosed with a chronic tic disorder.
The classes of medications most commonly linked to medication-induced tics include:
- Stimulants for ADHD
- Antidepressants
- Antihistamines
- Parkinson’s drugs
However, medication-induced tics are considered rare for most of these drugs when used appropriately. For many patients, treatment benefits outweigh risks of tics.
If new or worsened tics occur after starting a medication, talk to your doctor about potential management strategies. Never stop a prescribed medication abruptly without medical supervision.
Frequently Asked Questions
Can anxiety medications cause tics?
Anxiety medications like benzodiazepines (Xanax, Klonopin) have not been directly linked to causing tics or making them worse. However, anxiety itself can exacerbate tics. Managing anxiety with counseling, lifestyle changes, or appropriate medications if needed may indirectly improve tics.
Do ADHD medications cause Tourette’s syndrome?
No, ADHD stimulant medications do not cause Tourette’s syndrome. However, in someone with an underlying predisposition, stimulants may unmask or worsen tics. Tourette’s requires both motor and vocal tics lasting longer than a year.
Can blood pressure medications cause tics?
There is no evidence that blood pressure medications like beta blockers, ACE inhibitors, or calcium channel blockers cause tics. The possible exception is clonidine, which is sometimes used off-label to treat ADHD. Clonidine has been reported to potentially worsen tics in some cases.
Can antibiotics cause tics?
Antibiotics are not known to cause tics or exacerbate tics. Very rarely, abdominal discomfort from antibiotics could potentially cause stress that worsens tics.
Do sleep medications cause tics?
In general, sleep medications like zolpidem (Ambien), eszopiclone (Lunesta), or melatonin do not appear to cause or worsen tics. An exception is diphenhydramine (Benadryl), an older antihistamine sedative that has been linked to medication-induced tics.
Conclusion
While many classes of medications have been reported to potentially cause or worsen tics, these side effects appear to be quite rare for most modern medicines used at appropriate doses. Those already diagnosed with a chronic tic disorder are at greatest risk of medication-induced tics.
If new onset or worsening tics occur after starting a new medication, speak to your doctor about possible management strategies. Never abruptly stop a prescribed medication without medical guidance. With appropriate treatment, medication benefits often outweigh the risks of tic exacerbation for most patients.
