In clinical studies
The established safety profile of SINGULAIR was demonstrated in patients as young
as 12 months
Most frequently reported adverse events occurring at a frequency of >2% and more often than with placebo, regardless of causality assessment:
In children aged 12 months to 14 years with asthma
The safety profile in pediatric patients aged 12 months to 14 years was generally similar to the adult safety profile.
Additional adverse events in pediatric patients with asthma, occurring at a frequency of >2% and at an incidence greater than placebo, varied by age and were reported regardless of causality assessment. These included upper respiratory infection, sinusitis, pharyngitis, rash, fever, otitis, tonsillitis, rhinitis, diarrhea, wheezing, gastroenteritis, pneumonia, and conjunctivitis.
Safety and effectiveness of SINGULAIR in patients younger than 12 months with asthma have not been established.
Long-term safety profile
With prolonged treatment, the adverse-event profile in both adults with asthma (treatment for up to 2 years) and children aged 6 to 14 years with asthma (treatment for up to 1 year or longer) did not significantly change.
Additional safety information
- SINGULAIR should not be used as rescue medication to treat acute asthma episodes. Patients should be advised to have appropriate rescue medication available.
- Neuropsychiatric events have been reported in patients taking SINGULAIR. These events included agitation, aggressive behavior or hostility, anxiousness, depression, dream abnormalities, hallucinations, insomnia, irritability, restlessness, somnambulism, suicidal thinking and behavior (including suicide), and tremor. The clinical details of some postmarketing reports appear consistent with a drug-induced effect. Patients should be advised to report any neuropsychiatric events.
- In rare cases, patients with asthma on therapy with SINGULAIR may present with systemic eosinophilia, sometimes presenting with clinical features of vasculitis consistent with Churg-Strauss syndrome, a condition that is often treated with systemic corticosteroid therapy. A causal association between SINGULAIR and these underlying conditions has not been established.
Linear growth rate in pediatric patients
In a 56-week study of children aged 6 to 8 years with asthma,
Children taking SINGULAIR had growth rates similar to children taking placebo.
Change in height (cm) from randomization visit by scheduled week (treatment group mean + standard error of the mean)

Growth rates, expressed as least-squares (LS) mean (95% CI) in cm/year, for the treatment groups taking SINGULAIR, placebo, and beclomethasone were 5.67 (5.46, 5.88), 5.64 (5.42, 5.86), and 4.86 (4.64, 5.08), respectively (Study III).
The standard errors of the treatment group means in change in height are too small to be visible on the plot.
Study Designs
Study I: A 6-week, double-blind, placebo-controlled study of 172 pediatric patients aged 12 to 23 months, 124 of whom were treated with SINGULAIR.
Study II: SINGULAIR has been evaluated for safety in 573 pediatric patients aged 2 to 5 years in single- and multiple-dose studies.
Study III: A 56-week, multicenter, double-blind, randomized, active- and placebo-controlled parallel-group study of 360 pediatric patients aged 6 to 8 years with mild asthma. Patients were randomized to receive SINGULAIR 5 mg once daily, beclomethasone dipropionate (168 mcg twice daily with a spacer device; total daily dose=336 mcg). or placebo. The study compared the effect on linear growth of SINGULAIR vs placebo and beclomethasone, respectively. For each subject, a growth rate was defined as the slope of a linear regression line fit to the height measurements over 56 weeks.
SINGULAIR is indicated for prophylaxis and chronic treatment of asthma in patients aged 12 months and older and for prevention of exercise-induced bronchoconstriction (EIB) in patients aged 15 years and older.
For prevention of EIB, a single dose of SINGULAIR should be taken at least 2 hours before exercise. An additional dose of SINGULAIR should not be taken within 24 hours of a previous dose.
Patients already taking 1 tablet daily for another indication should not take an additional dose to prevent EIB.
SELECTED SAFETY INFORMATION
- SINGULAIR should not be used as rescue medication to treat acute asthma episodes. Patients should be advised to have appropriate rescue medication available.
- Neuropsychiatric events have been reported in patients taking SINGULAIR. These events included agitation, aggressive behavior or hostility, anxiousness, depression, dream abnormalities, hallucinations, insomnia, irritability, restlessness, somnambulism, suicidal thinking and behavior (including suicide), and tremor. The clinical details of some postmarketing reports appear consistent with a drug-induced effect. Patients should be advised to report any neuropsychiatric events.
- Use of SINGULAIR may not eliminate the need for inhaled or systemic corticosteroids. Patients should not decrease the dose or stop taking any other antiasthma medications unless instructed by a physician.
- Safety and effectiveness of SINGULAIR in patients younger than 12 months with asthma have not been established.
Before prescribing SINGULAIR, please read the Prescribing Information.