Cortisone has a bad reputation. It causes weight gain, thinning skin and increased infections. It is true in general that cortisone can cause these side effects. But asthma inhalers, when used as directed, do not contain enough cortisone for this to occur.
Cortisone and related substances
Asthma inhalers are actually falsely labelled as cortisone. In fact, cortisone cannot be used by the body – it is a degradation product of the body’s own stress hormone cortisol.
However, the hormone cortisol effectively stimulates the metabolism and also inhibits inflammation. This is precisely why the hormone and the drugs modelled after it are used to treat allergic asthma. They stop allergy-related inflammation and swelling of the airways.
Because the inhalers deliver the drug directly to the mucous membranes of the respiratory tract, a lower dose is required than with tablets. Inhalers therefore cause few side effects. This is another major advantage over tablets.
Asthma inhalers are recommended as a long-term basic treatment, except for very mild asthma symptoms in children. This means that they need to be taken every day, whether or not symptoms are present. Symptoms improve over time with treatment and respiratory distress occurs less frequently.
Few side effects from inhalers
It is important to use the correct inhaler technique to ensure that the drug reaches the lungs. This will depend on the type of inhaler. If performed incorrectly, the active substance remains in the mouth and throat area where it inhibits antimicrobial inflammation. This can lead to a fungal infection called oral thrush (Candidiasis). Oral thrush is characterised by a white or yellow coating resembling cottage cheese on the reddened oral mucous membrane. This coating can be scraped off but not completely removed. The symptoms can be prevented by either inhaling before meals or by rinsing the mouth, brushing the teeth or drinking something after inhalation.
Although the inhaler enables the active substance to reach the mucous membrane of the respiratory tract from outside the body, part of it is also absorbed into the bloodstream. Unlike tablets, however, this only occurs in small quantities. But very sensitive measuring methods reveal that inhalers also influence the production of cortisol in the adrenal glands: If the body detects that there is already cortisol in the blood – regardless of whether it was produced naturally or came from a medicine – it decreases the production of the hormone over time. However, the inhalers have very little impact on this.
Tablets are different: If they are suddenly discontinued, the body goes through a kind of cortisol withdrawal. Symptoms include significantly lower energy, muscle or joint pain similar to the flu, fatigue and the sensation of hypoglycemia. Cortisol treatment with tablets must be therefore be tapered off gradually.
This is not necessary for inhalers. “At a normal dosage, the impact of inhaled cortisone is too low to cause the sustained suppression that leads to withdrawal problems”, said Stephan Petersenn in response to an enquiry from ECARF. Petersenn is an endocrinologist and spokesperson for the German Society of Endocrinology (DGE). The experts therefore do not regard this as an issue. Inhalers can also be discontinued immediately even after long-term use once the allergy season is over and symptoms subside.
Nevertheless, Petersenn does warn that the use of high-dose inhaled glucocorticoids increases the risk of osteoporosis. Therefore, the current osteoporosis guidelines of the Association of Osteology e.V. recommend that certain persons who take inhaled cortisone for asthma at high doses should monitor their bone density through tests. This applies to women 50 years and older and men 60 years and older.
So why does cortisol have a bad reputation?
Cortisol was first administered to a patient in 1948. Cortisol-like drugs, or glucocorticoids, have been around for more than 50 years. Very little was known about these drugs at first, and therefore very high doses were used, which brought on the corresponding side effects. Glucocorticoids are now administered at a minimum dose for as short a period as possible (and of course at a high enough dose for as long as required). As a result, there has also been a decrease in severe side effects from tablet therapy.
Incidentally, the basic ingredient used by the body to make cortisol is cholesterol, which is converted into cortisol in several steps. The last step of this conversion takes place in the adrenal cortex, which is why the hormone is called cortisol (‘cortex’ is Latin for ‘bark’).
The substances in asthma inhalers, which act like cortisol but are produced artificially, are called ‘hydrocortisone’. These inhaled glucocorticosteroids, or ICS for short, include beclomethasone, budesonide, ciclesonide, fluticasone and mometasone. The inhalers do not act immediately after inhalation. Their effectiveness only begins after 12 to 24 hours and reaches a peak after three to seven days.
AWMF (Association of the Scientific Medical Societies). National care guidelines for bronchial asthma from 7 September 2020. Last retrieved on 26 June 2021. (In German)
AWMF (Association of the Scientific Medical Societies). Patient information on asthma – treatment with inhaled corticosteroids from 7 September 2020. Last retrieved on 26 June 2021. (In German)
Dachverband Osteologie e.V. (DVO – the umbrella organisation of German-speaking osteological societies). Osteoporosis guidelines 2017. Chapter 5.3.3. Glucocorticoids. (In German) Last retrieved on 26 June 2021. (In German)
Gelbe Liste (German drug directory). Kretschmer C.: Thrush (Candidiasis). Article dated 27 January 2020. Last retrieved on 26 June 2021. (In German)
Petersenn, Stephan. Press conference of the German Society of Endocrinology (DGE) on 16 June 2021 and ECARF email enquiry.