Singulair Side Effects: Quick Facts and Practical Tips

If you’ve been prescribed Singulair (montelukast) for asthma or allergies, you probably wonder what it might do to your body. The good news is most people tolerate it well, but a handful of side effects can pop up. Knowing the signs early helps you act fast and keep your treatment on track.

Common, Usually Mild Effects

About 1 in 10 users report mild symptoms that often fade after a few days. Typical complaints include:

• Headache – a dull throb that’s easy to treat with over‑the‑counter pain relievers.
• Nausea or stomach upset – take Singulair with food to ease discomfort.
• Fatigue – you might feel a bit sleepy, especially when you first start.
• Dry mouth – sip water or chew sugar‑free gum.

These issues rarely require stopping the medication. If they stick around, talk to your doctor about adjusting the dose or switching to an alternative.

Rare but Serious Reactions

Serious side effects are uncommon but worth watching for. Call a healthcare professional right away if you notice any of the following:

• Severe rash or hives – could signal an allergic reaction.
• Swelling of the face, lips, tongue, or throat – a medical emergency.
• Changes in mood or behavior – some users report anxiety, depression, or unusual thoughts.
• Chest pain or irregular heartbeat – especially important for people with heart conditions.
• Sudden vision changes or ringing in the ears.

While these events are rare, documenting when they happen (time of day, other meds, recent meals) helps your doctor pinpoint the cause.

Beyond the listed symptoms, a handful of reports link Singulair to neuropsychiatric effects, such as vivid dreams or agitation. If you’re a teen or an adult with a history of mood disorders, keep a close eye on any shifts in your mental state and discuss them at your next check‑up.

One practical tip: keep a simple side‑effect journal. Write down the date, what you felt, and any other factors (caffeine, stress, new supplements). Over a week or two you’ll see patterns that can guide a conversation with your prescriber.

If a side effect feels like a deal‑breaker, never stop the drug abruptly. Instead, taper under medical guidance or switch to another class of medication, such as an inhaled corticosteroid for asthma control.

In summary, Singulair is generally safe, with mild complaints being most common. Stay alert for rare, severe reactions, keep notes, and stay in touch with your healthcare team. By doing so, you’ll get the allergy‑relief or asthma‑control benefits without unnecessary hassle.