If you or your child has been prescribed montelukast — many folks know it by the brand name Singulair — you’re far from alone. It’s one of the most commonly prescribed maintenance medications for asthma and allergies in the country, and we fill it every single day at all four of our Walker Pharmacy locations. Here in Statesboro and across Bulloch and Toombs Counties, our pollen counts can climb high enough to make even the toughest farmer reach for a tissue, so it’s a familiar bottle on a lot of bathroom counters.

That said, montelukast is a medication I want patients to understand well. It’s effective, it’s affordable, and for the right person it can be life-changing. But it also carries an FDA Boxed Warning — the strongest warning the FDA issues — for serious mental health side effects, and that’s a conversation every patient and parent deserves to have with their pharmacist.

Whether you’re new to montelukast or you’ve been taking it for years, this guide is meant to give you the same clear, neighborly explanation I’d give if you walked into the pharmacy and asked me about it across the counter.

How Montelukast Works

When you breathe in something your body considers a trigger — pollen, dust, pet dander, smoke, even cold air during a morning walk — your immune system releases chemicals called leukotrienes. Leukotrienes are the bossy ones in the bunch. They tell the airways to tighten up, the lining of your nose and lungs to swell, and your body to crank out extra mucus. The result is wheezing, coughing, a stuffy nose, and that tight-chested feeling so many asthma and allergy patients know all too well.

Montelukast is what we call a leukotriene receptor antagonist. In plain English, it blocks the docking stations that leukotrienes need to deliver their message. The leukotrienes are still around, but they can’t make the airways panic. Taken once a day, montelukast quietly works in the background to keep asthma symptoms calmer and seasonal allergies more manageable. It is not, however, a rescue inhaler — if you’re having an asthma attack, it will not work fast enough to help. That’s what your albuterol is for.

Common Side Effects and How to Manage Them

Most patients tolerate montelukast well. The everyday side effects tend to be mild, but here are the ones we hear about most often at the counter:

• Headache — usually mild and often improves after the first week or two. Staying well-hydrated helps; if it lingers, let us know.
• Stomach upset or diarrhea — taking your dose with a small snack in the evening can settle things down.
• Cough, sore throat, or runny nose — frustrating because those are the very symptoms you’re trying to treat, but they typically ease as your body adjusts.
• Ear infections — reported more often in children. If your child has chronic ear trouble, mention it to the pediatrician.
• Fatigue — taking it in the evening, as it’s typically prescribed, helps any drowsiness work in your favor.

The more serious side effects — and the ones I want every single montelukast patient to know about — fall into the category of mood and behavior changes. We’ll cover those in the next section because they deserve their own space.

Things Your Pharmacist Wants You to Know

1. The FDA Boxed Warning is real, and it matters. In March 2020, the FDA placed a Boxed Warning on montelukast for serious mental health side effects, including agitation, depression, sleep disturbances, vivid or disturbing dreams, and suicidal thoughts or behavior. These reactions can show up in adults and children, sometimes within days of starting the medication and sometimes after months of use. The FDA also advised that for allergic rhinitis alone, montelukast should generally be reserved for patients who have not responded to or cannot tolerate other allergy treatments. If you or your child notices changes in mood, sleep, or behavior while taking montelukast, call your prescriber right away — and call us too. We’re happy to talk it through.

2. Take it every day, even when you feel fine. Montelukast is a maintenance medication. It works by keeping inflammation at bay over time, not by reacting in the moment. Skipping doses because your symptoms are quiet is one of the most common mistakes I see, and it sets folks up for flare-ups. Build it into your evening routine — right next to the toothbrush is a good spot.

3. Evening dosing isn’t an accident. Asthma symptoms tend to worsen overnight and into the early morning hours. Taking montelukast in the evening gives the medication time to peak when your airways are most vulnerable. If you’re using it specifically to prevent exercise-induced bronchospasm, your provider may direct you to take it at least two hours before activity instead — follow whichever instruction matches your prescription.

A Pharmacist’s Perspective

Growing up in this pharmacy, I watched my dad counsel patients on asthma medications back when our toolbox was a lot smaller than it is today. Montelukast was a real leap forward when it came on the market — a once-daily pill, no inhaler technique to master, and good results for a lot of people. For families juggling kids’ sports schedules, farm work, and the long pollen seasons we get in South Georgia, that simplicity has been a gift.

But the FDA’s 2020 Boxed Warning genuinely changed how I counsel on this medication. I now make a point of asking every new patient and every parent: do you know what to watch for? Most have never been told. So if you’re picking up a fresh prescription from our Statesboro, Brooklet, or Lyons counter, expect a few extra questions from your pharmacist. It’s not because we don’t trust the medicine — it’s because we want it working for you, not against you. That’s the kind of personal attention a community pharmacy can give that a mail-order tube in a brown box simply cannot.

Frequently Asked Questions

Can montelukast be taken in the morning instead of the evening?

For asthma and allergic rhinitis, evening dosing is recommended because that’s when it best matches your body’s overnight inflammation cycle. If evenings are tough to remember and you’d prefer morning dosing, talk to your prescriber or your Walker Pharmacy team before making the switch. For exercise-induced bronchospasm prevention, the dose is timed about two hours before activity, which may not be the evening at all.

Is it safe for children?

Montelukast is FDA-approved for children as young as 12 months for certain indications, with chewable tablets available for ages 2 to 5 and 6 to 14. That said, the Boxed Warning applies to children too. Parents should watch closely for any new irritability, agitation, sleep problems, nightmares, or behavior changes after starting the medication, and report them to the pediatrician right away. If your child has milder allergies, your doctor may want to try a different option first.

What happens if I miss a dose?

If you remember within a few hours, go ahead and take it. If it’s close to your next scheduled dose, skip the missed one and resume your normal evening routine. Do not double up — taking two doses at once doesn’t make the medication work better and can increase your chance of side effects.

Can I stop taking montelukast if my allergies improve?

Do not stop on your own. For seasonal allergies, your prescriber may build in a planned stopping point at the end of pollen season. For asthma, stopping abruptly can lead to a flare-up. Always check with your physician or pharmacist before discontinuing — we can help you weigh the timing.

Does montelukast interact with other medications?

Montelukast has fewer drug interactions than many medications, but it’s not interaction-free. Certain seizure medications, the antibiotic rifampin, and a few others can reduce its effectiveness. That’s why we always recommend keeping a complete, up-to-date medication list at the pharmacy — including over-the-counter products and supplements. We’ll spot interactions before they cause trouble.

Have Questions? We’re Right Down the Road.

Have questions about montelukast or any of your medications? Stop by Walker Pharmacy in Statesboro, Brooklet, or Lyons, call us at 912-681-3784, or visit walkerpharmacy.com. Need refills? Head to walkerpharmacy.com/refills. And if you’re tired of waiting on a chain pharmacy line or a mail-order delay, transferring your prescriptions takes just seconds at walkerpharmacy.com/transfer-prescriptions. We’d be honored to take care of you and your family.

This article is for informational purposes only and does not constitute medical advice. Always consult your physician or pharmacist before making changes to your medications.

— Jordan Walker, PharmD | Owner, Walker Pharmacy