Medications that worsen restless legs syndrome (RLS)

Antihistamines

Avoid antihistamines (like those in over the counter "PM" sleep aids). These medications cross the blood-brain barrier and can interfere with dopamine, the chemical in the brain that regulates movement and contributes to worsening restless legs syndrome (RLS).

The following antihistamine medications that are most associated with a flare-up of RLS symptoms are:

Diphenhydramine: Found in Benadryl and many over-the-counter sleep aids (like ZzzQuil or "PM" versions of pain relievers).
Chlorpheniramine: Commonly found in multi-symptom cold and allergy medications (such as Chlor-Trimeton).
Doxylamine: Often found in nighttime cold medicines like NyQuil.
Hydroxyzine: A prescription antihistamine (Vistaril, Atarax) used for itching or anxiety.

Safer antihistamine alternatives are second and third generation antihistamines. These are generally considered to be nondrowsy because they do not cross into the brain as easily. For many people with RLS, these are less likely to cause issues. Antihistamine recommended in RLS are:

Loratadine (Claritin)
Cetirizine (Zyrtec)
Fexofenadine (Allegra)
Levocetirizine (Xyzal)

Antidepressants

Many antidepressant medications are known to either cause or worsen Restless Legs Syndrome (RLS) as a side effect. This typically happens because most antidepressants increase serotonin levels in the brain, which facilitates an inhibitory effect on dopamine. Dopamine is the primary neurotransmitter involved in regulating leg movement. The following classes and specific medications are frequently associated with triggering or exacerbating RLS symptoms.

Mirtazapine (Avanza, Axit)

Mirtazapine (Avanza, Axit) is often cited in literature as having the strongest association with RLS in pharmacological antidepression treatments. This is likely due to its potent antihistamine properties combined with its effect on serotonin. Serotonin decreases dopamine which in turn worsens restless legs.

Selective Serotonin Reuptake Inhibitors (SSRIs)

Selective Serotonin Reuptake Inhibitors (SSRIs) is the most common class of antidepressants. While they work well for mood, they often worsen RLS. Common SSRIs include:

Sertraline (Zoloft)
Escitalopram (Lexapro, Esipram)
Fluoxetine (Prozac, Lovan)
Citalopram (Cipramil)
Paroxetine (Aropax)

Serotonin and Noradrenaline Reuptake Inhibitors (SNRIs)

Serotonin and Noradrenaline Reuptake Inhibitors (SNRIs) are effective antidepressants. However, they also increase serotonin leading to a decrease in dopamine and are frequently linked to RLS. SNRIs linked to RLS include:

Venlafaxine (Effexor)
Desvenlafaxine (Pristiq)
Duloxetine (Cymbalta)

Antidepression medications that do not worsen restless legs syndrome

Tricyclic antidepressants (TCAs) are older antidepressants that are sometimes used for sleep or nerve pain. TCAs for depression that do not worsen RLS include:

Amitriptyline (Endep, Tryptanol)
Nortriptyline (Allegron)

RLS friendly antidepressant and antianxiety medication alternatives that are considered to be "weight-neutral" or even potentially helpful for restless legs symptoms are:

Bupropion (Zyban, Prexaton). In Australia, this is primarily registered for smoking cessation, but it is often used off label for depression in RLS patients because it increases dopamine and noradrenaline rather than serotonin.
Vortioxetine (Trintellix): Some recent studies suggest it may be better tolerated by RLS patients than traditional SSRIs.
Agomelatine (Valdoxan): Since it works on melatonin and specific serotonin receptors (without a broad increase in serotonin levels), it is often considered a safer choice for sleep and RLS.

Antipsychotics

Antipsychotic medications are among the most common triggers for Restless Legs Syndrome (RLS). While antidepressants typically worsen RLS by increasing serotonin, antipsychotics do so by directly blocking dopamine (the chemical responsible for smooth muscle movement and coordination).

The connection between antipsychotics and restless leg syndrome

RLS is thought to be caused by a lack of dopamine activity in certain parts of the brain. Antipsychotics (neuroleptics) are used to manage symptoms like psychosis or mood instability. They block dopamine receptors (D2 receptors) triggering or intensifying the "urge to move" characteristic of RLS.

Antipsychotics most likely to worsen restless legs syndrome

Both older "typical" and newer "atypical" antipsychotics can cause RLS, though the risk level varies. First-generation (typical) antipsychotics have a very high affinity for dopamine receptors and are most likely to cause the RLS movement related side effects. These antipsychotics include:

Haloperidol (Haldol, Serenace)
Chlorpromazine (Largactil)
Flupentixol (Fluanxol)

Second-Generation (Atypical) antipsychotics while generally "gentler" on the motor system, many still frequently cause or worsen RLS including:

Risperidone (Risperdal)
Olanzapine (Zyprexa)

Lower-risk antipsychotics alternatives

While no antipsychotic is entirely "RLS safe," some have a lower tendency to block dopamine in the areas of the brain that control movement. Lower RLS risk antipsychotics include:

Quetiapine (Seroquel): In very low doses, it is sometimes better tolerated than others, though it remains a common trigger for many.

Clozapine (Clopine): This is considered the least likely to cause RLS or other movement disorders because it dissociates from dopamine receptors very quickly. However, it requires intensive blood monitoring and is usually reserved for treatment-resistant cases.
Aripiprazole (Abilify): Because this is a "partial agonist" (it acts like a thermostat, increasing or decreasing dopamine activity as needed), some patients find it doesn't trigger RLS as severely as full blockers.

Quetiapine (Seroquel) – Even though it is often used for sleep, it is a common RLS trigger.
Ziprasidone (Zeldox)

A note of caution

If you find that one or more of the medications you are taking may lead to worsening RLS don’t stop the medication abruptly as this can lead to serious consequences. Discuss this with your healthcare provider.