Dulera: Two Medications in One Inhaler

Dulera is a combination inhaler that contains two active medications working together to control asthma:

1. Mometasone furoate — an inhaled corticosteroid (ICS)
2. Formoterol fumarate dihydrate — a long-acting beta2-agonist (LABA)

Think of these as a one-two punch against asthma. One calms the inflammation that narrows your airways. The other relaxes the muscles around your airways to keep them open. Together, they tackle asthma from two different angles — which is why combination inhalers like Dulera are often more effective than either medication alone.

If you're new to Dulera, check out our complete overview: What Is Dulera? Uses, Dosage, and What You Need to Know.

Understanding Asthma: What's Happening in Your Airways

To understand how Dulera works, it helps to know what asthma does to your airways.

When you have asthma, two main problems occur:

1. Inflammation — The lining of your airways becomes swollen and irritated. This swelling narrows the space air can flow through, making it harder to breathe.
2. Bronchoconstriction — The smooth muscles wrapped around your airways tighten up, squeezing the airways even narrower.

Asthma triggers — like allergens, cold air, exercise, or respiratory infections — can set off both of these responses at the same time. The result is wheezing, coughing, chest tightness, and shortness of breath.

Dulera addresses both problems simultaneously.

How Mometasone Works (The Anti-Inflammatory)

Mometasone furoate is a corticosteroid — a type of medication that reduces inflammation. Here's what it does in your lungs:

• Reduces swelling in the airway lining by suppressing the inflammatory response
• Decreases mucus production so your airways stay clearer
• Reduces the number of inflammatory cells (like eosinophils and mast cells) in your airways
• Makes your airways less reactive to triggers over time

Mometasone works by entering the cells lining your airways and affecting how certain genes are expressed. It basically turns down the signals that tell your body to produce inflammation. This is a gradual process — you won't feel the full anti-inflammatory benefits for 1-2 weeks of regular use.

Key point: Mometasone treats the root cause of asthma (chronic inflammation), not just the symptoms. That's why daily use matters even when you feel fine.

How Formoterol Works (The Bronchodilator)

Formoterol fumarate is a long-acting beta2-agonist (LABA). It works by relaxing the muscles around your airways:

• Binds to beta2-adrenergic receptors on the smooth muscle cells surrounding your airways
• Triggers a chemical cascade that causes those muscles to relax
• Opens your airways wider so air flows more easily
• Effects last about 12 hours — which is why Dulera is taken twice daily

Formoterol has a unique advantage: it starts working within minutes (unlike some other LABAs that take longer). However, Dulera should never be used as a rescue inhaler. Even though you may feel some relief quickly, the corticosteroid component needs consistent daily use to work properly, and a rescue inhaler like albuterol is still needed for sudden asthma attacks.

Why Two Medications Are Better Than One

Research consistently shows that combining an ICS and a LABA provides better asthma control than increasing the dose of either medication alone. Here's why:

• They complement each other — The ICS reduces inflammation while the LABA opens airways. Different problems, different solutions.
• They enhance each other — Corticosteroids increase the number of beta2 receptors in your airways, making the LABA work better. The LABA, in turn, may help the corticosteroid work more effectively at the cellular level.
• Better outcomes with lower doses — Combining medications means you can use lower doses of each, which may reduce side effects compared to high-dose monotherapy.

What Dulera Does NOT Do

It's important to understand Dulera's limitations:

• It doesn't cure asthma — Dulera controls symptoms but doesn't eliminate the underlying disease.
• It doesn't work instantly for attacks — While formoterol kicks in quickly, Dulera is designed for daily maintenance, not emergency relief.
• It doesn't replace a rescue inhaler — Always keep albuterol or another short-acting bronchodilator on hand.
• It doesn't work if you skip doses — The anti-inflammatory benefit requires consistent, daily use to build up and maintain.

How Long Until Dulera Starts Working?

You may notice some improvement in breathing within minutes of your first dose — that's the formoterol opening your airways. But the full benefit of Dulera takes time:

• Minutes: Bronchodilation from formoterol
• Days to 1 week: Noticeable improvement in daily symptoms
• 1-2 weeks: Full anti-inflammatory effects from mometasone
• Ongoing: Continued improvement with consistent use over weeks and months

Don't give up on Dulera after a few days if you're not feeling dramatically better. Stick with it as prescribed and discuss any concerns with your doctor.

The Boxed Warning: What You Should Know

Dulera carries an FDA boxed warning about the LABA component (formoterol). LABAs were once linked to an increased risk of asthma-related death when used alone (without a corticosteroid). Because Dulera always delivers both an ICS and a LABA together, this risk is significantly reduced.

Still, the FDA recommends:

• Use Dulera only when asthma isn't controlled on an ICS alone
• Once asthma is well-controlled, your doctor may consider stepping down to an ICS-only inhaler

For more on safety, read our guide on Dulera side effects.

How Dulera Compares to Similar Inhalers

Other ICS/LABA combination inhalers work on the same principle but use different specific medications:

• Symbicort uses budesonide (ICS) + formoterol (same LABA as Dulera)
• Advair uses fluticasone (ICS) + salmeterol (a different LABA)
• Breo Ellipta uses fluticasone furoate (ICS) + vilanterol (LABA) — once daily

The mechanism of action is similar across all of these. The differences lie in the specific drugs, dosing frequency, inhaler device type, and side effect profiles. If Dulera isn't available, your doctor may switch you to one of these alternatives.

Why Understanding How Dulera Works Matters

Knowing how your medication works helps you:

• Stay motivated to use it daily — Even when you feel fine, the anti-inflammatory protection is working behind the scenes.
• Understand side effects — Most side effects make sense once you know the mechanisms (e.g., thrush from the corticosteroid, increased heart rate from the LABA).
• Communicate better with your doctor — You can have more informed conversations about your treatment plan.
• Recognize what's normal vs. concerning — Understanding the timeline helps set realistic expectations.

The Bottom Line

Dulera works by combining two proven approaches to asthma control: reducing inflammation with mometasone and opening airways with formoterol. Used consistently, it helps prevent asthma symptoms before they start. It's not a cure, and it's not a rescue inhaler — but for many patients with moderate-to-severe asthma, it's an important part of breathing easier every day.

If you're ready to start or refill Dulera, MedFinder can help you find it in stock near you.