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Singulair Lawsuits

Singulair lawsuits claim adults and children who took Singulair (montelukast) suffered severe mental health side effects and that Merck, the drug's manufacturer, failed to adequately warn patients, parents and doctors of the risk. There is no Singulair class-action lawsuit or MDL.

This is an active lawsuit

See If You Qualify for a Singulair Lawsuit

If you or a loved one was diagnosed with a mental health disorder after taking Singulair, you may be entitled to compensation.

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Last Modified: September 7, 2023
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Recent Singulair Lawsuit Updates

As of May 16, 2023, there have been no scheduled trials or court-approved global settlement in Singulair litigation. The Judicial Panel on Multidistrict Litigation has not consolidated any cases into one federal court.

  • April 2023: Massachusetts federal judge Timothy S. Hillman denied Merck’s motion to dismiss a Singulair lawsuit for lack of personal jurisdiction. He argued Merck manufactured, marketed and sold the drug in the state and allowed the case to continue.
  • February 2023: Judge Porto in the New Jersey MCL ruled Plaintiffs Facts Sheets for 30 cases in the first group of lawsuits were due Feb. 7, 2023.
  • December 2022: The judge decided on the Plaintiff Fact Sheet and authorization for use in the New Jersey MCL.
  • September 2022: Merck won a Wisconsin lawsuit that claimed Singulair cause a child’s suicidal and homicidal thoughts. The judge ruled federal drug labeling law preempted lack of warning claims.
  • January 2022: Singulair cases were consolidated into multicounty litigation in New Jersey.

Plaintiffs continue to file Singulair lawsuits across the country, but a large chunk of cases are pending in New Jersey. In July 2021, Plaintiffs’ lawyers requested the cases be consolidated in multicounty litigation in New Jersey.

The judge agreed and cases are now combined in MCL 637 in the Superior Court of New Jersey Law Division: Atlantic County.

Why Are Singulair Lawsuits Being Filed?

Plaintiffs, including the parents of children who suffered psychiatric disorders after taking Singulair, are filing lawsuits that accuse Merck of: Designing a defective drug, negligence and failure to warn about the risk of mental problems.

Singulair, also known as montelukast, is prescribed for severe allergies and asthma in adults and children. In March 2020, the U.S. Food and Drug Administration added a Singulair black box warning, its strongest label warning, for serious mental health side effects.

In September 2022, a Wisconsin judge ruled that one mother’s claim was preempted by federal law, barring her from suing Merck. As of November 2022, there are no new updates.

Families File Lawsuits

Lawsuits say Merck knew or should have known before it started selling Singulair in 1998 that the drug could cause neuropsychiatric injuries during treatment and even after stopping.

For example, a plaintiff filed a lawsuit on behalf of her child in the Eastern District of Wisconsin in September 2020. The plaintiff’s child took Singulair from December 2010 to August 2012. The drug caused her child to be admitted to an inpatient psychiatric center, according to the lawsuit.

Her child was admitted for homicidal and suicidal thoughts. Doctors diagnosed the child with major depressive disorder, anxiety disorder, obsessive-compulsive disorder, sexual thoughts, poor coping and other mental problems.

Singulair Black Box Warning Led to Lawsuits

Plaintiffs began filing lawsuits shortly after the FDA added a black box warning for serious neuropsychiatric events to Singulair’s drug label in March 2020.

A black box warning is the FDA’s most severe warning. These warnings contain important side effect information surrounded by a thick black border and bold lettering to warn of permanent, serious or fatal side effects. The Singulair black box warning links the drug to suicide, depression, aggression, agitation, suicidal thoughts and sleep disturbances.

Singulair Black Box Warning Timeline
  • March 4, 2020
    The FDA announced it was adding a black box warning for serious mental health side effects because many health care professionals, patients and caregivers were not aware of the risk.
  • Aug. 28, 2009
    The FDA announced an update to Singulair’s Precautions section of the prescribing information for neuropsychiatric events including, “postmarket cases of agitation, aggression, anxiousness, dream abnormalities and hallucinations, depression, insomnia, irritability, restlessness, suicidal thinking and behavior (including suicide), and tremor.”
  • March 3, 2008
    The FDA announced it was investigating “a possible association between the use of Singulair and behavior/mood changes, suicidality (suicidal thinking and behavior) and suicide.”
Were you or a loved one diagnosed with a mental health disorder after taking Singulair?

Do I Qualify for a Singulair Lawsuit?

If you or a loved one took brand name Singulair and received a diagnosis of a mental health disorder, such as those listed on the Singulair black box warning, you may qualify to file a Singulair lawsuit for compensation.

Neuropsychiatric disorders linked to Singulair include:
  • Major depressive disorder
  • Suicide
  • Institutionalization for psychiatric disorders
  • Obsessive-compulsive disorder
  • Homicidal thoughts
  • Suicidal thoughts
  • Non-psychiatric injury
  • Anxiety disorder
  • Other psychiatric disorders

In general, the time limit to file a claim for injuries caused by a drug is about three years, but this varies by state and may be less.

This can change depending on when you took the drug or when you discovered the drug’s side effects. Make sure you contact an attorney right away if you believe you qualify to file a claim.

Filing on Behalf of a Family Member

Parents or caregivers can file on behalf of their children, and family members can file a suit for loved ones who died as a result of Singulair side effects.

When parents file on behalf of their child, they claim damages they incurred as guardians of the child, such as paying for medical bills. They also file for injuries their child suffered. Wrongful death claims are filed on behalf of deceased family members.

Experienced law firms can walk parents and family members through the process of starting a claim.

Preparing to File a Lawsuit

Once you’ve confirmed you took brand name Singulair and have received a diagnosis, it’s time to start the lawsuit process.

Step 1: Finding an Experienced Law Firm

The first thing you need to do is find a law firm that has experience handling complex pharmaceutical litigation claims.

It’s an important decision, so make sure you ask about the firm’s track record and experience. Remember, you can interview more than one firm.

Step 2: Preparing Necessary Documentation

Once you’ve decided on the law firm you want to hire, sign up for a free consultation.

Before you talk to your attorney, make sure you have proof you took brand name Singulair, such as a receipt. Also gather medical records showing your diagnosis.

If you have difficulty getting these records, your attorney may be able to help.

Step 3: File the Claim

Once your attorney has determined you qualify to file a claim, he or she will start the process by writing up the complaint and filing the claim in the appropriate court.

Is There a Singulair Class-Action Lawsuit?

So far, there is no Singular class-action lawsuit or multidistrict litigation. The lawsuits currently being filed are individual lawsuits that claim Singulair’s manufacturer, Merck, failed to warn about the risk of mental health side effects.

Members of class actions don’t get to choose their attorneys, and all the members of the class are awarded the same amount of money regardless of the severity of their injuries. For this reason, most drug lawsuits similar to Singulair lawsuits are individual claims.

When hundreds or thousands of plaintiffs sue the same defendants for similar injuries, a judge may decide to consolidate the cases into MDL.

Cases in an MDL may share some resources such as discovery and experts, but each individual chooses their own lawyer and any settlement or jury verdict amount is based on the individual merits of their case.

Please seek the advice of a medical professional before making health care decisions.