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Singulair Side Effects

Singulair, or montelukast, is a drug used to treat asthma and help with allergy management. While Singulair is generally well-tolerated, it can cause serious side effects in certain people, including long-term side effects.

What Are Common Side Effects of Singulair?

Clinical data shows that Singulair, also known as montelukast, is a well-tolerated allergy medication that has several common side effects. The most prevailing is a headache, although clinical trials show that the number of people who reported it while taking the drug (18.4%) was only marginally higher than people who reported it after taking a placebo (18.1%).

The most common side effects of Singulair are:
  • Cough
  • Diarrhea
  • Earache or ear infection
  • Fatigue
  • Fever
  • Flu
  • Headache
  • Heartburn
  • Runny nose
  • Sinus headache
  • Sore throat
  • Stomach pain
  • Upper respiratory infection

Individuals taking Singulair may experience higher rates of fever and gastroenteritis, according to studies. However, clinical studies and trials conducted on Singulair show the medication’s benefits in treating conditions such as allergic rhinitis and asthma outweigh the risks of side effects.

Serious adverse reactions are rare, and the overall incidence of side effects with Singulair is low. Even long-term use of Singulair didn’t cause significantly more people to experience side effects.

Serious Singulair Side Effects

The vast majority of reactions to Singulair are rare and mild. However, the medication has some serious side effects. Although they’re especially rare, speak to a doctor immediately if you experience any of the following symptoms.

Serious Singulair side effects include:
  • Blistering, peeling or shedding skin
  • Difficulty breathing
  • Difficulty swallowing
  • Ear pain
  • Fever
  • Flu-like symptoms
  • Hives
  • Hoarseness
  • Itching
  • Pain and swelling of the sinuses
  • Pins and needles or numbness in the arms or legs
  • Rash
  • Swelling of the face, throat, tongue, lips or eyes

In some rare cases, hypersensitivity manifestations such as anaphylaxis and eosinophilic infiltration of the liver can occur after taking Singulair.

Lawsuit Information
People who were diagnosed with a mental health disorder after taking Singulair are filing lawsuits against the drug's manufacturer.
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Mental Health Effects of Singulair

The U.S. Food and Drug Administration requires a Singular black box warning that states that the medication is associated with serious mental health side effects for some people who take the drug. The boxed warning applies to everyone. Even those with no history of mental illness can be affected by the drug.

If you experience any of the following serious adverse effects, call the FDA’s MedWatch program at 1-800-332-1088 or file a report through the MedWatch page on the FDA website.

Mental health side effects of Singulair include:
  • Agitation, including aggressive behavior or hostility
  • Attention problems
  • Bad or vivid dreams
  • Depression
  • Disorientation or confusion
  • Feeling anxious
  • Hallucinations
  • Irritability
  • Memory problems
  • Obsessive-compulsive symptoms
  • Restlessness
  • Sleepwalking
  • Stuttering
  • Suicidal thoughts and actions
  • Tremor or shakiness
  • Trouble sleeping
  • Uncontrolled muscle movements

Some people who experienced mental health-related side effects after taking the medication filed Singulair lawsuits against its drugmaker, Merck. However, the FDA has not recalled Singulair and Merck has not removed it from the market. Singulair remains available as a prescription drug to treat asthma and other allergy and hay fever-like conditions.

For those concerned about serious side effects, discuss Singulair alternatives with your doctor. There may be other options that will work well for you.

Can Singulair Complications Be Prevented?

To help prevent potential complications associated with Singulair, check that the medication won’t interact with other drugs and supplements you already take. That includes any over-the-counter medications and dietary supplements. Discuss your medication and supplement history with your health care provider.

Some drugs, such as gemfibrozil (Lopid), interact with Singulair, increasing the risk of serious side effects. People with phenylketonuria, a rare genetic disorder, should know that aspartame is an ingredient in the chewable form of Singulair. Aspartame forms phenylalanine, which builds up in someone with PKU and can cause serious health problems.

If you have a liver condition, are pregnant, are trying to get pregnant or are nursing a baby, talk to your doctor before starting a regimen of montelukast. Also alert your physician if you have concerns about your children taking Singulair.

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