How steroid inhalers work: How to get the best from using them and prevent side effects

20th December, 2021 • 7 min read

What are steroid inhalers?

Steroid inhalers (also known as preventer inhalers or corticosteroid inhalers) are steroid sprays or powders that you breathe in through an inhaler.

Steroids are hormones that are made naturally in your body. The steroid medicine given to you by a doctor is similar to this natural hormone and it’s used to treat various medical conditions.

Steroid inhalers work by reducing inflammation and stopping your airways from narrowing if you have asthma or chronic obstructive pulmonary disease (COPD). You take them every day as prescribed to keep that inflammation down – so that if your airways come into contact with irritants like cold weather or excess mucus or an allergen like pollen – they are less likely to flare up and narrow. This can help you to breathe more easily and manage symptoms such as wheezing.

Read on to find out how the medicines in steroid inhalers work and the possible side effects.

Which conditions do steroid inhalers treat?

Steroid inhalers can be used to treat the symptoms of certain conditions, including wheezing and shortness of breath when it comes to:

  • asthma
    – a condition that appears to affect more women than men. Girls are twice as likely to develop asthma after puberty when compared to boys, which has been linked to hormonal cycles. More research is needed, but the numbers of men and women with asthma appear to even out after the menopause years
  • chronic obstructive pulmonary disease
    (COPD) – more women may be more likely to develop COPD as well, especially from smoking, or after being exposed to pollution or chemicals

Which conditions do steroid inhalers not treat?

Steroid inhalers reduce swelling and inflammation in the lungs. They do not treat conditions that affect the whole body, such as autoimmune diseases or joints conditions. These may instead be treated with

steroid injections
steroid tablets

Steroid inhalers should help to prevent asthma attacks. If you do have an acute asthma attack, you should use your reliever inhaler (most often blue in the UK) as well for on-the-spot relief if your symptoms start to get worse. This reliever inhaler works in a different way to your steroid (preventer) inhaler - by relaxing the muscles around your airways to open them up and let more air through.

What are the different types of steroids inhalers?

You can only get steroid inhalers on prescription from your doctor if you live in the UK, but other countries differ on this. Common steroid medications used in inhalers may be used alone or in combination with one another, depending on the condition you have.

These include:

  • beclometasone
  • budesonide
  • fluticasone
  • mometasone
  • ciclesonide

There are many types of steroid preventer inhaler, which may come in different colours, but most are brown. Some of the most common types include:

  • breath actuated inhalers (BAIs) – when you inhale, it releases a spray of medicine
  • metered dose inhalers (MDIs) – when you press the canister to release a puff of medication which you inhale in spray form. They are best used with a spacer
  • dry powder inhalers (DPIs) – gives the medicine in dry powder form, instead of a spray

How long do steroid inhalers take to work?

Steroid inhalers usually take 7 to 14 days to start improving symptoms because they work to reduce inflammation, which takes time. You should notice a difference after a week or so, but sometimes it can take up to 6 weeks to feel the full benefits.

Inhalers should always be used as prescribed by your doctor. The usual dose is 1 or 2 puffs in the morning and again at night, but this depends on the type of steroid you’re taking. Even if you start to feel better, a steroid inhaler should be used every day to keep the inflammation down and stop your symptoms from returning. This is why they are often called ‘preventer inhalers’.

What are the side effects of steroid inhalers?

Before you start with a steroid inhaler, tell your doctor if you:

  • have had an allergic reaction to steroids in the past
  • are pregnant, breastfeeding or trying for a baby – although most steroid inhalers are safe in pregnancy and for those breastfeeding
  • have
    (TB) or another infection in your lungs or airways

If you can use one safely, a steroid inhaler is best taken in exactly the same way that your doctor has told you to use it.

For example, using your steroid inhaler correctly and using a spacer – a hollow plastic tube with a mouthpiece at one end and a hole for the inhaler at the other – can help prevent some of the more mild and common side effects.

These may include:

  • a sore mouth or throat and a hoarse or croaky voice – washing your mouth with water or brushing your teeth after using a steroid inhaler can help reduce the risk of these effects
  • a cough
  • oral thrush
  • nosebleeds

If you’ve been using a steroid inhaler for a long time, or if you’re taking a high dose, there’s a chance you might notice some other side effects. These may include:

  • increased appetite
  • mood changes
  • difficulty sleeping

If you’re on a high dose preventer inhaler, you may be given a steroid emergency card, which you should carry on you at all times. This is used for emergency situations when it’s useful for doctors and other medical professionals to know that you take a high dose of steroids. Should you fall ill or become injured, a doctor will know that your body may not produce enough natural steroids and that you may need to be given more.

You should also not stop taking any steroids suddenly in case your body has stopped making enough natural steroids.

When to see a doctor if you’ve used steroid inhalers

Serious side effects for steroid inhalers are very rare, but they are more likely if you’re taking a high dose, or if you’ve been using your steroid inhaler for a long time.

See a doctor urgently if you’re using a steroid inhaler and notice:

  • your symptoms don’t get better after you’re using one regularly
  • your symptoms are getting worse
  • you keep needing your reliever inhaler more than 3 times a week

Call an ambulance if you’re using a reliever inhaler and you still feel very breathless. You should also see a doctor if you develop any symptoms you didn’t expect, or feel worried about your symptoms.

Some of the side effects you might get, such as oral thrush, can be treated with medication from a pharmacy, but see your doctor if it keeps coming back.

Rarely, high dose steroids can cause side effects similar to those of oral steroids. See a doctor if you think you have any of

these side effects

Sometimes, taking high dose steroids for a long time can also lead to a condition called

. You can help to prevent this by exercising regularly, not smoking, and eating a diet with enough

Key takeaways

  • steroid inhalers reduce inflammation in the airways and help improve symptoms of conditions such as asthma and chronic obstructive pulmonary disease
  • steroid inhalers are usually only available on prescription from your doctor
  • it can take between 7 and 14 days for the steroid medicine in your inhaler to work, but you should notice a difference after a week or so
  • steroid inhalers can cause mild side effects, but these are usually mild and go away after a few days. If you have side effects that don’t go away, see a doctor
  • there are lots of different types of steroid inhalers. Your doctor can recommend the best preventer inhaler for you based on your symptoms and general lifestyle.

Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.