Singulair Side Effects

Here's some background on Singulair before we jump into Singulair side effects. Singulair may be prescribed for different reasons and for patients of varying ages. It is used for both the treatment and prevention of asthma in adults as well as children over the age of one (1). Singulair is also used to relieve the symptoms of both seasonal (adults and children aged two (2) and older) and perennial allergic rhinitis (adults and children aged 6 months and older). Finally, this medication is also used to prevent the strained breathing (a.k.a. exercise-induced bronchoconstriction) that often accompanies exercising and vigorous workouts.

If you've ever struggled with breathing problems and had to use inhalers in the past then you'll really appreciate the fact that Singulair comes in various (easier-to-use-than inhalers) forms - tablets, chewable tablets and granules (...which are just perfect for young children and adults who can't chew or swallow tablets!). Note though, that Singulair will not stop an asthma attack that is already happening, for that you'll have to use an appropriate rescue medication. Okay, ready to delve into the all the Singulair side effects? Read on...

PS: Because Singulair is used for different conditions in people of different age groups, the side effects will be broken down as follows: Age Group & Condition

I think this will make it easier and faster for you find exactly the information you want for yourself or someone else.

Singulair Side Effects in Adults and Adolescents 15 Years of Age and Older - Asthma

• Abdominal pain
• ALT increased - a type of enzyme preoduced by the liver
• AST increased - a type of enzyme preoduced by the liver
• Asthenia - a general feeling of fatigue
• Cough
• Dental pain
• Dizziness
• Dyspepsia - indigestion
• Fever
• Headache
• Infectious gastroenteritis
• Influenza
• Nasal congestion
• Pyuria - the presence of pus/white blood cells in the urine
• Rash
• Trauma

Singulair Side Effects in Children With Asthma

6 to 14 Years Old:

• Diarrhea
• Dyspepsia - indigestion
• Fever
• Influenza
• Laryngitis - inflammation of the voice box
• Nausea
• Otitis - inflammation and/or infection of the ear(s)
• Pharyngitis - sore throat
• Sinusitis
• Viral infection

2 to 5 Years Old:

• Abdominal pain
• Conjunctivitis - pink eye
• Cough
• Dermatitis - inflammation of the skin
• Diarrhea
• Ear pain
• Eczema
• Fever
• Gastroenteritis - inflammation of the stomach and lining of the intestines
• Headache
• Influenza
• Otitis - inflammation and/or infection of the ear(s)
• Pneumonia
• Rash
• Rhinorrhea - runny nose
• Sinusitis
• Urticaria - hives
• Varicella - chicken pox

6 to 23 Months Old:

• Cough
• Otitis media - middle ear infection
• Pharyngitis - sore throat
• Rhinitis - runny or congested nose
• Tonsilitis - inflammation/infection of the tonsils
• Upper respiratory infection
• Wheezing

Singulair Side Effects Associated With Seasonal Allergic Rhinitis Use

Adults and Adolescents 15 Years of Age and Older:

• Somnolence - drowsiness
• Upper respiratory infection

Children 2 to 14 Years Old:

• Headache
• Otitis media - middle ear infection
• Pharyngitis - sore throat
• Upper respiratory infection

Singulair Side Effects Associated With Perennial Allergic Rhinitis Use

Adults and Adolescents 15 Years of Age and Older:

• Cough
• Epistaxis - nosebleeds
• Increase ALT - an enzyme produced by the liver
• Sinus headache
• Sinusitis
• Upper respiratory infection

Post-Marketing Singulair Side Effects

The following Singulair side effects were reported AFTER Singulair was approved and being used by the general population. You should note though that they were reported voluntarily by folks in the general population so there is therefore no way to determine how often they occur or if there is even really a true connection between them and Singulair.

• Agitation including aggressive behavior
• Angioedema
• Anxiousness
• Arthralgia - joint pain
• Bruising
• Cholestatic hepatitis - a type of liver disorder
• Depression
• Diarrhea
• Dream abnormalities
• Drowsiness
• Dyspepsia - indigestion
• Edema - swelling due to fluid retention
• Epistaxis - nosebleeds
• Erythema nodosum - inflammation of the fat cells under the skin
• Hallucinations
• Hepatocellular liver-injury - a type of liver disorder
• Hypersensitivity reactions including anaphylaxis
• Increased bleeding tendency
• Insomnia
• Irritability
• Mixed-pattern liver injury
• Myalgia (muscle pain) including muscle cramps
• Nausea
• Palpitations - fast heart rate
• Pancreatitis
• Paraesthesia/hypoesthesia - tingling feeling ("pins and needles" sensation)/numbness or decreased sensitivity
• Pruritus - itching
• Restlessness
• Seizures
• Suicidal thinking and behavior (including suicide)
• Systemic eosinophilia - an increased number of eosinophils (a type of white blood cell) in the blood
• Tremor
• Urticaria - hives
• Vomiting

There is nothing so sickening as to leaf
through a medical dictionary.
- Jules Renard

Drug Manufacturer Information

Merck & Co. Inc.,
One Merck Drive
Whitehouse Station, NJ 08889-0100

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November 15, 2009