Super Lawyers
Justia Lawyer Rating for Ronald V. Miller Jr.
Best Law Firms
Avvo Rating - 10
Million Dollar Advocates Forum
Litigator Awards

Singulair Lawsuit

This page is about Singulair lawsuits for victims who suffered mental health complications before there was a warning about the risks of these potential complications.

There is no Singulair class action lawsuit or MDL. Singulair lawsuits are filed in state or federal court alleging negligence failure to warn of potentially severe neuropsychiatric side effects.

These side effects include including depression, suicidal thoughts, and hallucinations. Singular lawsuits allege that Merck knew of the risk of these neuropsychiatric side effects, but did not communicate this knowledge to patients and doctors until 2020.

This page was last updated on September 6, 2022. Our law firm in not handling these claims.

Singulair Lawsuits - September 2022 Update

A mother who filed a Singulair lawsuit claiming the asthma drug caused her son’s suicidal and homicidal thoughts was dismissed after a federal judge in Wisconsin ruled that the claim was preempted by federal law

Singulair Lawsuits for Mental Health Side Effects

Singulair® (montelukast) is a popular prescription drug that is widely used for the treatment of asthma symptoms and the relief of seasonal hay fever allergies. Montelukast is known as a leukotriene receptor antagonist. Common side effects of montelukast were weakness and dizziness.

It was recently discovered, however, that prolonged use of Singulair may cause some users to develop mental health problems. Our law firm is now seeking new cases from people who were diagnosed with mental health disorders after using Singulair.

About Singulair

Singulair TimelineThe active ingredient in Singulair, montelukast, was developed and patented by Merck & Co. Inc. and first approved for clinical use in the U.S. in 1998.

Since then, Singulair has become a very widely used prescription medication for the treatment of asthma and seasonal allergy symptoms. The original patent protection on Singulair is expired so it is available in both brand and generic form.

Singulair is not a steroid, like most asthma medications. Instead, it works by blocking certain chemicals in the body called leukotrienes which are released in response to allergens and other triggers and cause airways to tighten and fluid to invade the respiratory system.

Over 9 million people in the U.S. had Singulair prescriptions dispensed in 2019, either as an add-on or alternative to inhaled corticosteroid medications. A large percentage of Singulair patients are children. 2.3 million patients who received Singulair prescriptions were under 17, which is roughly 30% of all users.

FDA Requires New “Black Box” Warning for Neuropsychiatric Side Effects Linked to Singulair

One of the unique aspects of Singulair is that can cross over the blood-brain barrier (“BBB”). It is one of the few types of medications that are known to cross the BBB, which is a protective barrier that protects the brain from pathogens. Singulair’s ability to cross the BBB means that the drug gradually accumulates in the central nervous system and eventually the brain tissue.

When Singulair accumulates in the nervous system and brain, it can cause neuropsychiatric events and mental health disorders. Studies have shown that prolonged Singulair users are twice as likely to develop mental health disorders. Children who use montelukast have an even higher risk level for this side effect.

The link between Singulair and neurologic problems was first identified back in 2007. This discovery prompted Merck to update the warning label on Singulair in 2008 to include information about the risk of neuropsychiatric events with prolonged use. But in 2020, the Food and Drug Administration required Merck to use a so-called “black box warning” (the highest level of drug warning) on Singulair moving forward.

The new black-box label for Singulair contains a heightened warning about the considerable risk of serious mental health issues attributed to the extended use of Singulair's active ingredient - montelukast. The label identifies aggression, depression, and suicidal thoughts and behaviors as some of the potential mental health disorders associated with the drug. In addition to the black box warning, the FDA also requires a new medication guide to be given to all patients who receive a new montelukast prescription.

These new requirements by the FDA were prompted by a collection of medical studies that found that the risk of mental health disorders from Singulair from significantly higher than compared to traditional steroid medications for asthma.

The net result of the new warning label and medication guidance is that doctors are basically advised not to prescribe Singulair unless alternative medications are not an option. In effect, Singulair’s risk of mental health issues has made the drug a treatment option of last resort.

Singulair (Montelukast) Lawsuits

Lawsuits are now being filed against Merck by individuals who used Singulair (or a generic version of montelukast) and were subsequently diagnosed with a mental health disorder or experienced a neuropsychiatric episode resulting in physical harm.

These Singular lawsuits allege that Merck was fully aware of the risk of neuropsychiatric problems associated with Singulair, but deliberately concealed them and failed to warn doctors and patients. Plaintiffs in montelukast lawsuits are seeking damages for medical expenses, lost wages, and pain and suffering connected to mental health disorders by users of Singulair.

FAQs – Singulair Lawsuits

Is Singulair safe to use?

Singulair has not been recalled. But many believe it should not be used by young patients (18 and under) because it has been linked to a high risk of mental health disorders and neurologic abnormalities.

Can Singulair (montelukast) cause psychosis?

Singulair (montelukast) has been linked to neurologic events and mental health disorders and can potentially cause psychosis.

Can Singulair cause anxiety?

Yes. Singulair has been scientifically linked to neurologic problems and mental health disorders, including anxiety.

Does Singulair (montelukast) have a black box warning label?

Yes. As of March 2020, the FDA required Singulair (montelukast) to contain a so-called black box warning label on the risk of mental health disorders and problems associated with the drug.


Client Reviews
★★★★★
They quite literally worked as hard as if not harder than the doctors to save our lives. Terry Waldron
★★★★★
Ron helped me find a clear path that ended with my foot healing and a settlement that was much more than I hope for. Aaron Johnson
★★★★★
Hopefully I won't need it again but if I do, I have definitely found my lawyer for life and I would definitely recommend this office to anyone! Bridget Stevens
★★★★★
The last case I referred to them settled for $1.2 million. John Selinger
★★★★★
I am so grateful that I was lucky to pick Miller & Zois. Maggie Lauer
★★★★★
The entire team from the intake Samantha to the lawyer himself (Ron Miller) has been really approachable. Suzette Allen
★★★★★
The case settled and I got a lot more money than I expected. Ron even fought to reduce how much I owed in medical bills so I could get an even larger settlement. Nchedo Idahosa