Parkinson’s disease is a progressive neurological disorder that affects movement, balance, and brain function — and while it’s commonly linked to genetics and aging, new evidence in 2025 suggests some medications may also play a role in triggering or accelerating its symptoms.

These findings are raising concern, especially among people managing chronic conditions with long-term prescriptions. If you’re taking medications for mental health, gastrointestinal issues, or allergies, it’s worth understanding how these drugs may impact your brain.

Let’s explore the most commonly flagged medications and what researchers, neurologists, and patients are saying now.

What Is Parkinson’s Disease?

Parkinson’s is caused by a loss of dopamine-producing neurons in a part of the brain called the substantia nigra. This results in:

Tremors

Slowed movement

Muscle rigidity

Balance issues

Cognitive changes

While age and genetics remain the most established risk factors, environmental influences — including medication — are now being studied more closely.

What Are Drug-Induced Parkinsonism Symptoms?

Some medications don’t directly “cause” Parkinson’s, but they can produce Parkinson’s-like symptoms, a condition called drug-induced parkinsonism (DIP). This is often reversible, but in some cases, symptoms persist or progress.

Common signs include:

Trembling in the hands or arms

Slowness of movement

Stiffness or rigidity

Mask-like facial expressions

Shuffling gait

If symptoms begin after starting a new medication, this may be a red flag.

1. Antipsychotic Medications

Used to treat schizophrenia, bipolar disorder, and severe depression, antipsychotics are one of the most commonly linked drug classes.

Examples include:

Haloperidol (Haldol)

Risperidone (Risperdal)

Olanzapine (Zyprexa)

Chlorpromazine (Thorazine)

These drugs block dopamine receptors, which can mimic the dopamine loss seen in Parkinson’s disease.

2. Anti-Nausea and GI Medications

Some medications used for nausea and acid reflux also block dopamine.

Examples:

Metoclopramide (Reglan)

Prochlorperazine (Compazine)

Promethazine (Phenergan)

Long-term or high-dose use of these drugs has been associated with persistent tremors or stiffness, especially in older adults.

3. Calcium Channel Blockers (CCBs)

Used to treat high blood pressure and heart arrhythmias, some CCBs have been associated with parkinsonism in rare cases.

While not all CCBs carry this risk, researchers are exploring links with certain types like flunarizine and cinnarizine, more common in Europe and Asia.

4. Mood Stabilizers and Antidepressants

Certain antidepressants and mood stabilizers can influence dopamine pathways.

Examples being studied:

Lithium

SSRIs (e.g., sertraline, fluoxetine) in rare cases

Tricyclic antidepressants (amitriptyline)

While the overall risk is low, long-term use combined with other meds may increase susceptibility.

What You Shouldn’t Do: Stop Medications Suddenly

It’s tempting to panic — but suddenly stopping medications can be dangerous and life-threatening, especially for those managing psychiatric or cardiac conditions.

Instead:

Talk to your doctor or neurologist

Ask if there are alternatives with lower neurological risk

Discuss gradual weaning or rotating treatment plans

Monitor for early signs of motor symptoms

In most cases, there are safer options or dosage adjustments that can reduce risk without compromising your treatment plan.

When to See a Specialist

If you or a loved one is experiencing:

Tremors that worsen over time

Stiffness or slowness after starting a new med

Facial masking or balance issues

…it’s worth consulting a neurologist, ideally one who specializes in movement disorders. Early detection gives you more time to adapt and adjust your plan.

How to Reduce Risk Now

Keep a medication list and review it annually

Report any new symptoms immediately

Consider getting a second opinion on long-term prescriptions

Stay active — physical activity is protective for brain health

Stay informed about new research and treatment changes

In 2025, doctors are becoming more aware of medication-linked Parkinson’s symptoms and can help navigate safer, personalized care.