How to Use an Inhaler Properly, With and Without a

What this article covers

Why does the inhaler fail so many patients?
How to use a pressurised MDI without a spacer
Using a spacer: why it makes a real difference
Dry powder inhalers: the opposite of what you expect
Errors most patients do not know they are making
Keeping your inhaler clean and effective
When to use your reliever and when to get help
Specific considerations for children and older adults

Why does the inhaler fail so many patients?

The pressurised metered dose inhaler (MDI) is the most widely used device for delivering medicine to the airways, and also one of the most error-prone. A systematic review and meta-analysis published in NPJ Primary Care Respiratory Medicine in 2025 found that a substantial proportion of patients with asthma and COPD continue to make technique errors even after receiving verbal or written instruction. Education helps, but errors persist unless the technique is checked by demonstration and corrected in person.

The core problem is physics. Medicine leaves the MDI canister at high speed and deposits on the back of the throat rather than reaching the small airways of the lungs. The throat is closer and easier to reach than the deep lung, which means inhaler error does not simply waste medicine; it deposits inhaled corticosteroid in the mouth and throat where it is not wanted, increasing the risk of local side effects.

A separate meta-analysis published in the same journal in 2017 catalogued the most common errors: inspiratory flow that is too fast, failing to actuate the canister at the start of the breath, holding the device at an angle, and not breath-holding after inhalation. Each of these errors independently reduces the fraction of the dose reaching the lung.

How to use a pressurised MDI without a spacer

Before starting, shake the inhaler vigorously for five seconds. The propellant and medicine can separate, and the shake redistributes them before each dose. If the inhaler is brand new or has not been used for more than a week, fire one test puff into the air before inhaling.

Breathe out gently to empty your lungs without forcing. Place the mouthpiece between your lips and form a tight seal. Begin a slow, deep breath in through your mouth and simultaneously press the canister down once. Continue breathing in slowly until your lungs are full. Hold your breath for 10 seconds to allow particles to settle on the airway walls, then breathe out slowly.

If you need a second dose, wait a full minute between actuations, not just a few seconds. The first dose slightly opens the airways, allowing the second dose to penetrate deeper on the same breath path.

The most common error is breathing in too fast or too briefly. Medicine particles are tiny and follow the airstream. If the air moves quickly, particles collide with walls rather than travelling in suspension to the lung.

MDI inhaler: the correct sequence

1Shake the inhaler for five seconds
2Remove the cap and breathe out gently to empty your lungs
3Place the mouthpiece in your mouth and seal your lips around it
4Begin a slow, deep breath in and press the canister at exactly the same moment
5Continue breathing in slowly until your lungs are completely full
6Hold your breath for 10 seconds, then breathe out slowly
7Wait one full minute before a second dose
8Rinse your mouth with water if using an inhaled corticosteroid

Using a spacer: why it makes a real difference

A spacer is a plastic or metal tube that fits between the inhaler and your mouth. The medicine is fired into the spacer first, slows down, and you then inhale it at your own pace. This slowing is the key mechanism: particles have time to become smaller before they enter your mouth, and they travel through the throat without impacting its walls.

A 2025 review published in the Journal of Aerosol Medicine and Pulmonary Drug Delivery confirmed that a spacer significantly increases lung drug delivery compared to MDI alone, particularly for patients who cannot reliably coordinate pressing the canister with the start of their breath. The benefit is greatest for exactly the patients who struggle most with coordination.

Spacers are essentially mandatory for children under eight, who cannot reliably coordinate pressing and breathing. A face mask attachment is needed for children under four who cannot create a seal around a mouthpiece. Adults also benefit from spacers, particularly in the first days after starting a new inhaler or when breathlessness makes coordination harder during an episode.

How to use an MDI with a spacer

1Shake the inhaler and attach it to the end of the spacer
2Place the mouthpiece in your mouth or apply the mask firmly to your child's face
3Fire one puff into the spacer
4Immediately breathe in slowly and deeply from the spacer
5If you hear a whistle from the spacer valve, you are breathing too fast: slow down
6Hold your breath for 10 seconds then breathe out slowly
7Wait one minute before the next dose

Dry powder inhalers: the opposite of what you expect

Dry powder inhalers (DPI) contain no propellant gas. Instead, they rely entirely on the speed and force of your own breath to break up the powder and carry it to the lungs. This is the exact opposite of MDI technique: the faster and harder you breathe in, the better the drug delivery.

Common DPI errors are: breathing out into the device before inhaling (which wets the powder and causes it to clump), breathing in too slowly or weakly, and not holding the breath afterwards. Different DPI devices are loaded differently: some load automatically when you twist or click, others require manual loading. Read the instructions for your specific device or ask a pharmacist to demonstrate.

Never use a spacer with a dry powder inhaler. A spacer reduces the airflow velocity that the DPI needs to disperse the powder. Also avoid storing DPIs in humid environments such as bathrooms, because moisture damages the powder and reduces its effectiveness.

Errors most patients do not know they are making

Head tilted forwards during inhalation is a common silent error. Keeping the head straight or very slightly tilted back opens the airway more fully. A head tilted forward narrows the throat and increases the surface available for medicine to deposit before it reaches the airways.

Firing the canister before the breath starts, or a fraction of a second after, means the spray cloud has already begun to disperse before it is drawn in. With an MDI without a spacer, the press and the start of the breath must be simultaneous. With a spacer, this matters far less because the medicine waits in the chamber.

Failing to shake the inhaler is more consequential than most patients realise. The propellant and active drug separate between uses. Without shaking, the spray comes out poorly mixed, producing large droplets that deposit in the mouth rather than reaching the lung.

Forgetting to rinse the mouth after inhaled corticosteroid is not a minor inconvenience. Corticosteroid particles that land in the mouth and throat suppress local immunity and create conditions for fungal overgrowth. The resulting oral thrush (candidiasis) appears as white patches or a sore, burning feeling in the mouth. A thorough rinse with water, gargled and spat out, after every dose prevents this effectively.

Many patients also do not know that the primary way their preventer inhaler fails them is not the medicine itself, but years of subtly incorrect technique that meant the preventer never actually reached the right part of the lung. If your asthma has been poorly controlled for a long time despite regular preventer use, ask a pharmacist or nurse to watch you use your inhaler from start to finish. The solution may be technique, not dose.

Keeping your inhaler clean and effective

A blocked mouthpiece delivers a reduced dose. Wash the mouthpiece cap with warm water weekly and allow it to dry completely before replacing it. Do not submerge the canister itself in water. A partially blocked nozzle can be difficult to detect and can account for several weeks of poorly controlled symptoms before anyone notices.

Spacers also need weekly cleaning in warm water. Crucially, do not rub the inside of a plastic spacer with a cloth or towel. The friction creates static electricity that attracts drug particles to the plastic walls and away from the airstream. Leave the spacer to air dry instead.

Check the dose counter on your inhaler regularly. Many modern inhalers have a counter that shows remaining doses. Do not rely on shaking the inhaler to estimate how much is left. The propellant gas continues to produce a sound and sensation of liquid when shaken even after the drug content is exhausted, which means you may be inhaling propellant without medicine.

When to use your reliever and when to get help

The reliever inhaler such as salbutamol begins working within 5 to 10 minutes of a correctly taken dose. If you need your reliever more than three times a week for symptoms, your asthma is not well controlled and your preventer treatment needs reviewing. This is not a reason to take more reliever; it is a signal to see your doctor.

If you take your reliever and symptoms do not begin to improve within 15 to 20 minutes, do not simply repeat the dose multiple times at home. This is a sign that the episode is more severe and needs medical assessment. Repeated reliever use can delay seeking the help that is actually needed.

People who use two or more types of inhaler need to know clearly which is which. The reliever is for acute symptoms only. The preventer is taken daily even when you feel entirely well, because it works by reducing underlying airway inflammation over time. Using the preventer only during episodes provides none of its protective benefit.

Specific considerations for children and older adults

Children under eight are generally unable to coordinate pressing the canister with starting a breath. A study published in The Journal of Asthma in 2015 confirmed that inhaler technique in children using MDI with a spacer was significantly better than in those using MDI alone. A face mask spacer is essential for children under four. As children grow, they can transition to a mouthpiece spacer and eventually to a standard inhaler with proper instruction.

Older adults may have weakened grip strength or stiff joints that make pressing the canister difficult. Breath-actuated inhalers, which fire automatically in response to the breath rather than requiring a manual press, are an alternative worth discussing with a prescriber. Older patients may also have weaker inspiratory flow, which can limit DPI performance and makes MDI with a spacer a more reliable choice.

In any household where multiple family members have respiratory conditions, each person needs their own inhaler prescribed to the correct type and dose. Sharing an inhaler transfers bacteria and viruses even if the mouthpiece is wiped. If cost or availability is a constraint, this is worth raising with the prescribing doctor, who may be able to suggest alternatives.

With the Sihtak app you can log how many times you have used your reliever inhaler each week. That number alone tells your doctor a great deal about how well your condition is controlled. The AI assistant can also help you understand what your lung function test results mean.

Frequently asked questions

Do I really need a spacer or is it just for children?

Spacers improve medicine delivery for all ages, not only children. If you cannot consistently coordinate pressing the canister with the start of your breath, a spacer will deliver more drug to your lungs than the inhaler alone. It is particularly important for children under eight and useful for anyone during a breathless episode.

Why can I taste the medicine in my throat after inhaling?

Tasting medicine in the throat means a significant proportion of the dose has deposited there instead of reaching the lungs. The most common causes are breathing in too fast, firing the canister slightly before or after the breath starts, or holding the device at an angle. Using a spacer reduces this substantially.

How often should my inhaler technique be reviewed?

Research shows that technique deteriorates over time even among people who were taught correctly. Ask your doctor or pharmacist to check your technique at every annual review, and immediately any time you are switched to a different inhaler device, because different devices require different technique.

Can I store my inhaler in the car?

Do not leave your inhaler in a closed car, particularly in the heat of a Middle Eastern summer. Temperatures inside a parked car can exceed 60 degrees Celsius and may degrade the medicine and increase canister pressure. Carry the inhaler with you or store it in a cool, shaded place.

Is inhaled corticosteroid safe for long-term use?

Yes. Inhaled corticosteroids at prescribed doses are safe for long-term use and are the cornerstone of asthma management. The amount entering the bloodstream is tiny compared with oral or intravenous steroids. Rinsing your mouth after each dose minimises the small risk of oral thrush.

Can I share my inhaler with a family member if they have the same condition?

No. Inhalers are personal medical devices. Sharing transfers bacteria and viruses between users even if the mouthpiece is cleaned. Each person needs their own prescribed device at the dose appropriate for their own condition.

My reliever does not seem to work anymore. What should I do?

Check the technique first, then check the dose counter to confirm the inhaler is not empty. If technique is correct and the device is not empty, a reliever that is less effective than before is a clinical sign that needs medical assessment, not just a higher dose of reliever.

Should I use the reliever or the preventer first when taking both?

Take the reliever first if you have symptoms, wait 5 to 10 minutes for it to open the airways, then take the preventer. The open airways allow the preventer to penetrate deeper. Follow this order consistently and ask your prescriber to confirm it applies to your specific combination of inhalers.

Sources

This content is for health education only and is not a substitute for medical advice. If you have symptoms that worry you, see your doctor.