Understanding Steroids, Cortisol, ACTH and Adrenal Suppression in Aspergillosis
For people with Allergic Bronchopulmonary Aspergillosis (ABPA), severe asthma and other forms of aspergillosis, steroid treatment can be both extremely helpful and medically complicated.
Many patients are prescribed corticosteroids such as prednisolone or methylprednisolone to control inflammation, improve breathing and reduce the risk of lung damage. These medicines can be very effective. However, repeated or long-term steroid treatment can also affect the body’s natural hormone system, especially the adrenal glands.
Some patients are told:
- “Your cortisol is low.”
- “Your ACTH level is abnormal.”
- “You may have adrenal suppression.”
- “This may be steroid withdrawal.”
- “The blood tests are difficult to interpret.”
This can be worrying and confusing, especially when symptoms are severe but the explanation is not straightforward.
This article explains why adrenal problems can occur in some people with aspergillosis and severe asthma, why blood tests such as cortisol and ACTH can be difficult to interpret, and why steroid treatment sometimes involves a careful balance between benefit and risk.
Key points summary
- Steroid medicines can reduce the body’s own natural cortisol production.
- This is called adrenal suppression or adrenal insufficiency.
- Symptoms may overlap with aspergillosis, asthma, infection, fatigue or steroid withdrawal.
- Blood tests such as cortisol and ACTH can be difficult to interpret.
- Inhaled steroids and antifungal medicines can also influence steroid effects.
- Long-term prednisolone is generally avoided where possible, but it may still be necessary for some patients.
- Patients should not stop or reduce steroids suddenly without medical advice.
- Severe symptoms such as collapse, vomiting, dehydration, confusion or severe weakness require urgent medical advice.
Contents
- What do the adrenal glands do?
- What are cortisol and ACTH?
- Why are steroids used in ABPA and aspergillosis?
- Are steroids only meant for short-term use?
- How steroids affect the body’s natural hormone system
- What is adrenal suppression?
- Why symptoms can be difficult to recognise
- Why blood tests can become confusing
- The role of inhaled steroids
- Antifungal medicines and steroid interactions
- Steroid withdrawal versus adrenal insufficiency
- What kinds of stress may require higher steroid doses?
- When should patients seek urgent medical advice?
- Frequently asked questions
- Final thoughts
What do the adrenal glands do?
The adrenal glands are small glands that sit above the kidneys. They produce several important hormones, including cortisol.
Cortisol helps the body:
- respond to stress,
- maintain blood pressure,
- regulate energy levels,
- support immune function,
- and cope with illness or infection.
The body carefully controls cortisol levels through a hormone signalling system involving the brain, the pituitary gland and the adrenal glands.
What are cortisol and ACTH?
ACTH stands for adrenocorticotropic hormone.
The pituitary gland in the brain releases ACTH to tell the adrenal glands to produce cortisol.
This system normally works as a feedback loop:
- When cortisol is low, ACTH usually rises.
- When cortisol is high, ACTH usually falls.
Cortisol levels naturally change during the day and are usually highest in the early morning. This is one reason why many cortisol blood tests are taken around 9am.
Why are steroids used in ABPA and aspergillosis?
In Allergic Bronchopulmonary Aspergillosis (ABPA) and some severe asthma conditions, the immune system reacts strongly to Aspergillus fungi.
This can cause:
- airway inflammation,
- wheezing,
- coughing,
- mucus plugging,
- breathlessness,
- worsening lung function,
- and repeated flare-ups.
Steroids such as prednisolone are often used because they reduce inflammation quickly and effectively.
Some patients may need:
- short courses during flare-ups,
- repeated courses,
- long-term low-dose treatment,
- inhaled steroid therapy,
- antifungal treatment,
- or biologic medicines to reduce the need for oral steroids.
For many patients, steroids are not optional or casual medicines. They may be essential treatments used to control serious inflammation and protect lung function.
Are steroids only meant for short-term use?
Patients sometimes hear that prednisolone was “only designed for short-term use”. This is understandable, because modern medical practice tries to avoid long-term steroid treatment where possible.
Long-term oral corticosteroids can cause significant side effects, including:
- adrenal suppression,
- diabetes or worsening blood sugar control,
- osteoporosis and fracture risk,
- increased infection risk,
- cataracts or glaucoma,
- muscle weakness,
- skin thinning and bruising,
- weight gain,
- sleep disturbance,
- and mood or mental health effects.
For this reason, doctors usually aim to use steroids at the lowest effective dose for the shortest safe time.
However, it is also important not to oversimplify this message. Some people with ABPA, severe asthma or other inflammatory lung conditions do need longer-term steroid treatment because the disease itself can be dangerous if not controlled.
In some patients, the risk of uncontrolled lung inflammation may outweigh the risks of steroid treatment, at least for a period of time.
Modern care increasingly tries to reduce steroid exposure by using other approaches where appropriate, such as:
- antifungal treatment,
- biologic medicines for severe asthma or ABPA-type inflammation,
- careful monitoring of lung function and blood tests,
- gradual steroid tapering,
- bone protection where needed,
- diabetes monitoring,
- and regular review of whether the steroid dose can be reduced.
The key message is not that patients have done anything wrong by needing steroids. The key message is that long-term steroid treatment deserves careful monitoring, honest discussion and regular review.
Patient reassurance: If you have needed prednisolone for ABPA or severe asthma, this does not mean you have failed or made a poor choice. It usually means your medical team has been trying to control a potentially serious inflammatory condition. The aim is to balance benefit and risk as safely as possible.
Balancing risks and benefits
One of the hardest parts of long-term steroid treatment is that two important things can be true at the same time:
- steroids can cause serious side effects,
- and steroids can also prevent serious lung damage and dangerous flare-ups.
Patients sometimes feel guilty, frustrated or frightened when they hear about the risks of prednisolone. Others may feel judged for “still being on steroids”.
However, many people with ABPA or severe asthma did not choose steroids lightly. Steroids are often prescribed because uncontrolled inflammation itself can damage the lungs, worsen bronchiectasis, increase hospital admissions and significantly reduce quality of life.
Modern respiratory care increasingly tries to reduce steroid exposure where possible using:
- antifungal therapy,
- biologic medicines,
- careful monitoring,
- gradual tapering plans,
- and better recognition of steroid side effects.
But for some patients, steroids may still remain an important part of treatment, even if the goal is eventually to reduce the dose.
The most helpful approach is usually not “steroids are good” or “steroids are bad”, but rather:
- What dose is truly needed?
- Can the dose be safely reduced?
- Are side effects being monitored properly?
- Are there alternative treatments available?
- And is the patient being listened to when symptoms change?
This balanced approach is increasingly recognised as one of the most important parts of caring for people with severe asthma and aspergillosis.
How steroids affect the body’s natural hormone system
Steroid medicines act in ways that are similar to natural cortisol.
When the body senses steroid medication in the bloodstream, it may reduce its own ACTH production. Over time, this can mean:
- ACTH falls,
- the adrenal glands become less active,
- and natural cortisol production decreases.
Doctors sometimes describe this as the adrenal glands “going to sleep”.
This is called:
- adrenal suppression,
- steroid-induced adrenal insufficiency,
- or hypothalamic-pituitary-adrenal axis suppression.
What is adrenal suppression?
Adrenal suppression means the body may not produce enough cortisol when it is needed.
This can become especially important during:
- infection,
- surgery,
- injury,
- severe stress,
- or rapid steroid reduction.
Some patients develop symptoms gradually. Others notice problems when trying to reduce steroid doses.
Because cortisol is part of the body’s stress response, people with adrenal insufficiency may need specific medical advice about what to do during illness, vomiting, surgery or severe infection.
Why symptoms can be difficult to recognise
Symptoms of adrenal suppression can overlap with many other conditions common in people with aspergillosis, ABPA or severe asthma.
Possible symptoms include:
- profound tiredness,
- weakness,
- dizziness,
- sweating,
- shakiness,
- nausea,
- muscle aches,
- low mood,
- brain fog,
- reduced exercise tolerance,
- poor recovery after illness,
- or feeling suddenly much worse after reducing steroids.
These symptoms may also occur with:
- an ABPA flare,
- asthma worsening,
- lung infection,
- chronic illness,
- poor sleep,
- anxiety,
- or steroid withdrawal.
This overlap is one reason why patients can feel frustrated or uncertain. Symptoms are real, even when the cause is difficult to pin down.
Why blood tests can become confusing
Many patients expect blood tests to give clear answers, but cortisol and ACTH results are often complicated.
Several things can affect results:
- time of day,
- recent steroid use,
- the type of steroid used,
- inhaled steroid dose,
- recent dose reductions,
- illness or stress,
- laboratory methods,
- and antifungal medicines.
Typical patterns
In classic steroid-induced adrenal suppression:
- cortisol is low,
- and ACTH is low or “inappropriately normal”.
This happens because steroid medication suppresses ACTH production.
However, real-life cases are not always straightforward. Some patients may have recently reduced steroids, missed doses, changed steroid type, used high-dose inhaled steroids, or taken antifungal medicines that alter steroid metabolism.
In some situations, endocrinologists may need repeated testing or dynamic tests such as a Synacthen test to understand whether the adrenal glands can respond properly.
It is important that patients do not try to interpret cortisol or ACTH results in isolation. The result needs to be understood alongside symptoms, medication history, timing of the sample and the clinical situation.
The role of inhaled steroids
Many people assume inhaled steroids only affect the lungs.
Inhaled steroids usually have fewer whole-body effects than long-term oral steroids, but high doses can sometimes contribute to adrenal suppression, especially when combined with:
- long-term or repeated oral steroid courses,
- azole antifungal medicines,
- other medicines that affect steroid metabolism,
- or individual differences in how medicines are processed.
This does not mean inhaled steroids are unsafe or should be stopped suddenly. For many people with asthma or ABPA, inhaled steroids are an important part of keeping airway inflammation under control.
It does mean that total steroid exposure should be reviewed carefully, especially in patients with symptoms suggestive of adrenal suppression.
Antifungal medicines and steroid interactions
This is an especially important issue in aspergillosis.
Antifungal medicines such as:
- itraconazole,
- voriconazole,
- posaconazole,
- and isavuconazole
can interact with other medicines, including corticosteroids.
Some azole antifungals slow the breakdown of steroids in the liver. This can increase the body’s exposure to steroid medication, meaning that even doses which initially appear moderate may sometimes behave more like higher doses inside the body.
This interaction may increase the risk of:
- adrenal suppression,
- Cushing-like side effects,
- weight gain,
- skin thinning,
- easy bruising,
- high blood sugar,
- muscle weakness,
- or hormonal imbalance.
The interaction can be particularly important in patients taking:
- oral prednisolone or methylprednisolone,
- high-dose inhaled steroids,
- multiple steroid preparations together,
- or repeated steroid courses over time.
Some patients tolerate steroid treatment reasonably well for long periods before antifungal medicines are added. Endocrine problems may then become more noticeable later, especially during:
- infection,
- surgery,
- vomiting or diarrhoea,
- major physical stress,
- rapid steroid reduction,
- or severe asthma or ABPA flare-ups.
This can feel as though adrenal insufficiency has appeared “suddenly” or “out of nowhere”, when in reality the adrenal glands may have been partially suppressed for some time.
Why adrenal insufficiency may only become obvious during illness or stress
Some patients with steroid-related adrenal suppression cope reasonably well during normal day-to-day life, especially while still taking regular steroids. However, the problem may become much more noticeable when the body faces significant physical stress.
Under normal circumstances, the body rapidly increases cortisol production during severe illness or injury. If the adrenal glands cannot respond properly, symptoms may suddenly become much more severe.
Patients sometimes describe:
- “crashing” during an infection,
- extreme exhaustion,
- severe weakness,
- dizziness or collapse,
- poor recovery after illness,
- or feeling suddenly unable to cope physically.
This does not mean every severe illness in an ABPA patient is caused by adrenal insufficiency. Infections, inflammation and lung disease themselves are often the major problem. However, adrenal suppression can sometimes contribute to deterioration and may only reveal itself during periods of stress or acute illness.
This is one reason why some patients are given “sick day rules”, emergency steroid cards or advice about temporary steroid dose increases during illness.
Importantly, this does not mean antifungal medicines are “bad” or should be avoided. In many patients, antifungal treatment significantly improves ABPA control and may eventually help reduce steroid exposure overall. The important message is that these combinations require awareness, monitoring and careful medical supervision.
Patients should never stop antifungal or steroid medicines suddenly without medical advice.
Steroid withdrawal versus adrenal insufficiency
Steroid withdrawal and adrenal insufficiency can feel very similar.
Steroid withdrawal
When steroid doses are reduced, the body may take time to adjust. Patients can temporarily feel unwell even if the adrenal glands are slowly recovering.
Adrenal insufficiency
Adrenal insufficiency means the body cannot produce enough cortisol to meet its needs.
Symptoms may overlap considerably. Recovery can sometimes take weeks or months, and in some patients longer.
For many patients, one of the hardest parts is that they may “look well” externally while feeling exhausted internally.
It is important that symptoms are not dismissed simply because they are difficult to measure.
What kinds of stress may require higher steroid doses?
Patients who have adrenal insufficiency or significant adrenal suppression may sometimes be advised to temporarily increase steroid doses during periods of physical stress. This is often called following “sick day rules”.
The body normally produces extra cortisol during stress, illness or injury. If the adrenal glands cannot respond properly, extra steroid medication may sometimes be needed to prevent serious illness.
Examples of situations that may place significant stress on the body include:
- high fever or significant infection,
- chest infection or pneumonia,
- vomiting or diarrhoea,
- COVID-19 or influenza,
- major dental treatment or surgery,
- fractures or significant injury,
- general anaesthetic procedures,
- severe asthma attacks or ABPA flare-ups,
- hospital admission with acute illness,
- or severe physical exhaustion associated with illness.
The exact advice varies between patients depending on:
- whether adrenal insufficiency has been formally diagnosed,
- the steroid dose currently being taken,
- how suppressed the adrenal glands are thought to be,
- other medical conditions,
- and guidance from endocrine or respiratory specialists.
Some patients are provided with:
- specific “sick day rules”,
- an emergency steroid card,
- medical alert jewellery,
- or emergency hydrocortisone injection kits.
Patients should only adjust steroid doses according to the advice provided by their medical team. If severe vomiting, collapse, confusion, inability to keep medication down or major deterioration occurs, urgent medical advice is needed.
When should patients seek urgent medical advice?
Patients should seek urgent medical help if they experience:
- collapse,
- fainting,
- severe vomiting,
- inability to keep steroid medication down,
- severe dehydration,
- confusion,
- severe weakness,
- very low blood pressure,
- or sudden major deterioration during illness.
These symptoms can occasionally indicate adrenal crisis, which is a medical emergency.
Patients who have been told they are at risk of adrenal insufficiency should follow the emergency and “sick day” advice given by their endocrine or respiratory team.
Frequently asked questions
Does everyone taking steroids develop adrenal suppression?
No. Risk depends on factors such as dose, duration, repeated courses, inhaled steroid dose, other medicines and individual sensitivity.
Can adrenal function recover?
Yes. Many patients gradually recover adrenal function over time, although recovery speed varies.
Are inhaled steroids safer than tablets?
Inhaled steroids usually have fewer whole-body effects than long-term oral steroids, but high doses can still contribute to adrenal suppression in some patients, especially when combined with certain antifungal medicines.
Why do I feel worse when reducing steroids?
This can happen for several reasons. The underlying lung disease may flare, the body may be adjusting to lower steroid levels, or cortisol production may not yet have recovered.
Does needing long-term prednisolone mean something has gone wrong?
Not necessarily. Long-term prednisolone is usually avoided where possible because of side effects, but some patients need it to control serious inflammation. The aim is regular review, careful monitoring and dose reduction when it is safe.
Should I stop steroids because of this risk?
No patient should stop prescribed steroids suddenly unless specifically advised by their medical team. Sudden withdrawal can be dangerous, especially if the body’s own cortisol production is suppressed.
Final thoughts
Adrenal suppression and steroid-related hormone problems are recognised complications of corticosteroid treatment.
For patients with aspergillosis, ABPA and severe asthma, the situation can become especially complex because:
- steroid treatment may be medically necessary,
- symptoms overlap with many other conditions,
- antifungal medicines may interact with steroids,
- inhaled steroids may add to total steroid exposure,
- and blood tests are not always straightforward.
Patients sometimes feel frustrated because their symptoms are difficult to explain or measure clearly. However, these experiences are recognised by clinicians and researchers, and steroid-related adrenal problems are increasingly acknowledged as important and sometimes under-recognised.
The goal is not to create fear of steroids. The goal is to use them carefully, monitor them properly, reduce them when possible, and support patients through the difficult process of balancing disease control with treatment side effects.
Suggested internal links
- ABPA treatment overview
- Steroid side effects
- Antifungal drug interactions
- Fatigue and aspergillosis
- Severe asthma and biologics
- Living with long-term aspergillosis
- Mental wellbeing and chronic illness
- Aspergillosis.org Knowledge Hub
References and further reading
When was this article last reviewed?
Last reviewed: May 2026
Author and review information
Prepared for patient education and support purposes.
This article is intended for general educational use and should not replace personalised medical advice from a healthcare professional.
A Drop of Blood, Real-Time Answers
Last reviewed: 20 March 2026
Audience: Patients, carers, families, and non-specialists
Topic: Point-of-care monitoring of antifungal drug levels
New bedside testing for antifungal drugs — and why patients welcome it
For many people taking antifungal medicines, blood tests are an important part of care. These tests help doctors check whether the amount of medicine in the body is too low, too high, or about right.
A new type of technology is being developed to do this much more quickly, using just a single drop of blood placed onto a specialised chip. Instead of sending blood away to a laboratory and waiting days for a result, this kind of test may be able to provide an answer much more quickly, sometimes during the clinic visit itself.
Patients in a recent focus group responded very positively to this idea. They welcomed not only the technology itself, but also what it could mean for their care: less waiting, less uncertainty, fewer trips to hospital, and more personalised treatment.
Key points
- A new test can measure antifungal drug levels from a drop of blood.
- The blood is placed on a specialised chip containing tiny sensors.
- Results may be available much faster than standard laboratory testing.
- This could help doctors adjust treatment more quickly and more precisely.
- Patients in a focus group strongly welcomed the technology.
- Reported benefits included less anxiety, fewer hospital visits, and more confidence in treatment decisions.
What is this new test?
This is a type of point-of-care test. That means it is designed to be used close to the patient, such as in a clinic or at the bedside, rather than sending the sample away to a central laboratory.
In this case, the aim is to measure the level of an antifungal drug in the blood from a very small sample, sometimes just a finger-prick drop. The drop of blood is placed onto a specialised chip. That chip contains tiny channels and sensors that can detect the amount of drug present.
People sometimes describe this type of system as a “lab on a chip” because it performs some of the work of a laboratory in a very small device.
How does the technology work?
The exact science varies between devices, but the general idea is similar.
- A small blood sample is taken.
This may be from a finger prick rather than a larger blood draw. - The blood is placed onto a specialised chip.
The chip is designed to handle a tiny volume of blood. - The blood moves through microscopic channels.
These channels guide the sample to the parts of the chip that do the measurement. - Sensors on the chip detect the antifungal drug.
These sensors are designed to recognise the drug or react to it in a measurable way. - A reader produces a result.
A connected device reads the signal from the chip and estimates the drug level.
Some systems use electrical signals, some use light, and some use chemical reactions. Patients do not need to understand all the engineering details to understand the main point: the chip is acting like a mini laboratory.
A simple way to think about it is this:
Instead of sending your blood sample to a distant laboratory, this technology brings part of the laboratory to your fingertip.
Why do antifungal drug levels matter?
Some antifungal medicines need careful monitoring because the “right” level can be quite important.
If the drug level is too low, the medicine may not work well enough. If the drug level is too high, side effects may become more likely.
This can be especially relevant for antifungal drugs such as:
- itraconazole
- voriconazole
- posaconazole
Drug levels can vary from person to person for many reasons, including:
- how well the body absorbs the medicine
- interactions with other medicines
- differences in liver function and metabolism
- changes in health over time
At present, monitoring usually involves sending blood to a laboratory. That works, but it can mean delays. Results may not come back quickly enough to guide decisions during the clinic appointment itself.
A faster bedside test could help clinicians make treatment decisions more quickly and could support more personalised care.
What did patients say about it?
In the patient focus group, this technology was widely welcomed. Patients were not only interested in the novelty of the test. They also recognised several practical benefits that could make day-to-day care easier and safer.
1. Faster results could reduce anxiety
Many patients described the stress of waiting for test results. Waiting can create a sense of uncertainty: Is the treatment working? Is the dose correct? Are side effects more likely?
A test that gives much quicker results was seen as reassuring. Instead of waiting days, patients liked the idea of getting answers much sooner, possibly while still in clinic.
2. Fewer visits could reduce the burden of care
For many people with chronic lung conditions or long-term illness, going to hospital is not a small task. Travel, parking, breathlessness, fatigue, mobility problems, and long waits can make even a short appointment exhausting.
Patients felt that a faster and simpler test could reduce some of this burden, especially if it could be built into a normal appointment or eventually be offered closer to home.
3. More personalised dosing felt important
Patients often understand from experience that medicines do not affect everyone in the same way. One person may tolerate a treatment well, while another may have side effects or absorb the medicine differently.
Because of this, patients valued the idea that treatment could be adjusted based on their own measured drug level, rather than relying only on standard dosing. This gave a stronger sense that care was being tailored to the individual.
4. Closer monitoring gave reassurance about safety
Antifungal drugs can be very helpful, but patients also know that some of them can have side effects and interactions. That can make treatment feel worrying, especially over longer periods.
Patients said that being able to check drug levels more quickly and more easily could help them feel safer. It suggested that treatment was being watched closely rather than left unchecked between appointments.
5. Immediate results could help patients feel more involved
Another important theme was involvement. Patients often feel that blood is taken, results disappear into the system, and decisions come later without much real-time discussion.
By contrast, a bedside result creates the possibility of discussing the number there and then. Patients felt this could help them better understand their treatment and feel more involved in decisions about dose changes and ongoing care.
6. It seemed to fit better with real life
Patients repeatedly emphasised that long-term treatment has to fit around real lives, not just clinic systems. Many welcomed the idea of a test that was quicker, simpler, and potentially more convenient.
In that sense, what patients welcomed was not just a chip or a machine, but a model of care that felt more responsive and more human-centred.
What could this mean for future care?
If this technology proves accurate, reliable, and affordable, it could support a different way of monitoring antifungal treatment.
Possible future benefits could include:
- drug level testing during the clinic appointment itself
- faster dose adjustment when levels are too high or too low
- closer monitoring when starting or changing treatment
- fewer repeat visits just to check blood levels
- potential future use in community settings or, one day, at home
It is important to be realistic. New technologies must be carefully tested before they become routine. They need to be shown to be accurate, dependable, and practical in real healthcare settings.
Even so, patients clearly recognised the potential. For them, this is not just about speed. It is about moving toward care that is:
- more responsive
- more personalised
- more convenient
- less anxiety-provoking
Common questions
Is this available now?
Usually not as a routine test in most healthcare settings. It is still being developed and studied, although interest in this type of monitoring is growing.
Will this replace ordinary blood tests?
Not immediately. Standard laboratory testing is still important. New bedside systems may first be used alongside existing methods while they are being evaluated and introduced.
Would this work for every antifungal drug?
Not necessarily. Some devices may be designed for specific drugs first. Wider use would depend on the technology and the evidence supporting it.
Could this be used at home?
Possibly one day, but that is likely to depend on how reliable, affordable, and easy to use the technology becomes. For now, clinic or bedside use is the more immediate possibility.
Why is a drop-of-blood test appealing to patients?
Because it may mean quicker answers, less uncertainty, fewer hospital trips, and more confidence that treatment decisions are based on what is happening in their own body.
When to seek medical advice
You should contact your healthcare team if you:
- develop new or worsening side effects from your antifungal medicine
- feel your treatment is not helping
- have concerns about drug interactions with other medicines
- are unsure whether to continue, stop, or change your medication
A new bedside test could support treatment decisions, but it would not replace medical advice. Symptoms, scans, blood tests, and clinical review would still matter.
Final thoughts
This new chip-based bedside technology may sound futuristic, but the reason patients welcomed it is very straightforward.
They saw the possibility of care that is faster, clearer, safer, and better adapted to real life.
In other words, this is about more than measuring a drug level from a drop of blood. It is about moving away from delayed, one-size-fits-all monitoring and toward real-time, personalised, patient-centred care.
In one sentence
A tiny chip and a drop of blood could help doctors adjust antifungal treatment more quickly — and patients believe that could make care less stressful, less burdensome, and more personal.
Can blood tests help predict if chronic pulmonary aspergillosis will come back?
This study from the National Aspergillosis Centre (NAC) looked at people with chronic pulmonary aspergillosis (CPA) who had completed antifungal treatment and asked a simple question:
Can blood tests tell us who is more likely to relapse after treatment stops?
What the researchers did
Doctors reviewed patients with CPA who had:
-
Taken antifungal treatment for at least 6 months
-
Stopped treatment because they were clinically stable
They then followed these patients to see who stayed well and who relapsed, and compared this with their blood test results at the time treatment stopped.
What they found
-
About 1 in 4 patients had a relapse after stopping treatment
-
People whose Aspergillus IgG blood test was still high at the end of treatment were much more likely to relapse
-
Patients whose IgG level had fallen to a lower level did not relapse in this study
-
Signs of Aspergillus allergy or sensitisation also increased relapse risk
-
CT scan appearances and treatment length alone were not reliable predictors
Why this matters for patients
This means that:
-
Blood tests may help doctors decide when it is safe to stop treatment
-
Some people may need closer follow-up or longer treatment
-
Follow-up can be more personalised, rather than “one size fits all”
Importantly, a relapse does not mean treatment failed — it reflects how persistent this infection can be in damaged lungs.
Key takeaway
A simple blood test at the end of treatment may help predict who needs closer monitoring for CPA relapse.
This research supports a more individualised approach to long-term CPA care.
Antifungal Medicines: Dosing, Monitoring, and the Role of Specialist Care
A detailed reference for patients and non-specialist clinicians
1. Why antifungal treatment is different from most medicines
Oral antifungal medicines—especially azole antifungals—are essential for treating long-term fungal diseases such as chronic pulmonary aspergillosis and allergic bronchopulmonary aspergillosis.
They differ from many common medicines because they:
-
Have a narrow margin between effectiveness and toxicity
-
Behave very differently between individuals
-
Are often taken for months or years, not days
-
Interact with many commonly prescribed drugs
For these reasons, antifungal treatment requires individualised dosing, monitoring, and specialist input, rather than a standard fixed dose.
2. What “pharmacokinetics” means (plain language)
Pharmacokinetics describes what the body does to a drug:
-
Absorption – how well the drug enters the bloodstream from the gut
-
Distribution – how effectively it reaches tissues such as the lungs
-
Metabolism – how quickly the liver breaks it down
-
Elimination – how the drug leaves the body
Differences at any of these stages explain why the same dose can be ineffective for one person and toxic for another.
3. Different generations of azole antifungals behave differently
Each generation of azole antifungal was designed to improve effectiveness, but chemical changes also altered how the body handles the drug.
First-generation azoles (older drugs)
Examples
-
Ketoconazole
-
Fluconazole (limited activity against Aspergillus)
Key features
-
Variable absorption
-
Shorter half-life
-
Less reliable lung penetration
Clinical relevance
-
Rarely used now for chronic aspergillosis
Second-generation azoles (mainstay treatment)
Examples
-
Itraconazole
-
Voriconazole
-
Posaconazole
Key features
-
Excellent lung and tissue penetration
-
Highly variable metabolism between people
-
Strong interaction with liver enzymes
Clinical relevance
-
Very effective
-
Blood levels vary widely
-
Dose adjustment and monitoring are often essential
Newer azoles
Example
-
Isavuconazole
Key features
-
More predictable absorption
-
Long, stable half-life
-
Fewer extreme peaks and troughs
Clinical relevance
-
Often better tolerated long-term
-
Monitoring still important, but dosing may be more stable
4. Why the “right dose” matters so much
Too little antifungal
-
Infection not adequately controlled
-
Symptoms persist or worsen
-
Risk of antifungal resistance
-
Fewer future treatment options
Too much antifungal
-
Liver irritation or damage
-
Nausea, appetite loss
-
Neurological or visual side effects
-
Drug accumulation, especially with long-term use
The aim is always the lowest dose that effectively controls the fungus.
5. How clinicians know whether the dose is right
No single test determines this. The correct dose is identified when three elements align:
1️⃣ Blood level testing (therapeutic drug monitoring)
-
Measures how much drug is actually in the bloodstream
-
Helps identify:
-
Under-dosing
-
Target-range dosing
-
Toxic levels
-
2️⃣ Clinical response
-
Symptoms stabilise or improve
-
Fewer flare-ups or complications
-
Better day-to-day function
3️⃣ Safety monitoring
-
Liver and kidney blood tests
-
Review of side effects
-
Ongoing assessment of drug interactions
Only when effectiveness and safety are both acceptable is the dose considered “right”.
6. Why the right dose can change over time
A dose that was correct initially may later need adjustment because of:
-
Weight or body-composition changes
-
Age-related metabolic changes
-
New medications (including antibiotics or steroids)
-
Changes in liver or kidney function
-
Gradual drug accumulation during long-term therapy
Regular review is therefore expected and appropriate.
7. Is it sometimes impossible to find a stable dose?
Yes. For a minority of patients, a perfectly balanced dose cannot be found.
Reasons include:
-
Extremely fast or slow drug metabolism
-
A very narrow safety window
-
Long-term toxicity despite “acceptable” blood levels
-
Unavoidable interacting medications
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Liver, kidney, or neurological vulnerability
-
Partial or full antifungal resistance
In these cases, the dose that controls the fungus and the dose that causes side effects may overlap.
This reflects biological limits, not treatment failure.
8. What clinicians do when a stable dose cannot be achieved
Options may include:
-
Switching to a different azole with different pharmacokinetics
-
Using modified dosing schedules (split dosing, slower titration)
-
Accepting a lower suppressive dose rather than full eradication
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Considering non-azole antifungals where appropriate
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Prioritising symptom control and quality of life
All are intentional, safety-focused decisions.
9. The central role of the specialist pharmacist
Specialist pharmacists are key to safe antifungal care, particularly for long-term azole therapy.
They play a critical role in:
Interpreting drug levels
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Assessing whether a level is truly low or high
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Accounting for dose timing and formulation
-
Preventing unnecessary or unsafe dose changes
Managing drug–drug interactions
Azoles interact with many common medicines, including:
-
Steroids and inhalers
-
Heart rhythm drugs
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Blood thinners
-
Anti-epileptics
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Pain medications
The specialist pharmacist:
-
Reviews the full medication list
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Anticipates interactions before harm occurs
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Advises on adjusting both interacting drugs
Individualising dosing
When standard doses do not work, they help design:
-
Non-standard doses
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Split dosing schedules
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Slow titration plans
-
Alternative azoles with different pharmacokinetics
Protecting patients during long-term treatment
They monitor:
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Trends in liver and kidney tests
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Signs of cumulative toxicity
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Whether symptoms may be drug-related rather than disease-related
Coordinating care
They act as a bridge between:
-
Laboratory results
-
Clinical decision-making
-
Patient experience
Their involvement often changes management, not just fine-tunes it.
10. Where antifungal drug level testing is done in the UK
In the UK, antifungal drug level testing is centralised.
-
Blood samples are taken locally
-
Samples are sent to specialist reference laboratories, most commonly the
Mycology Reference Centre Manchester -
Results are returned to the local clinical team for interpretation
Patients managed through specialist services such as the
National Aspergillosis Centre
benefit from integrated expertise in antifungal pharmacology, imaging, and long-term monitoring.
This process is routine and standard for antifungal care.
11. Key reassurance for patients
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Dose changes are normal and expected
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Side effects are often biology-driven, not your fault
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Blood tests make treatment safer, not riskier
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Switching drugs is a planned strategy, not giving up
12. One-paragraph summary
Antifungal medicines—particularly azole antifungals—have complex and highly variable behaviour in the body, with a narrow balance between effectiveness and toxicity. Safe use requires individualised dosing, therapeutic drug monitoring, symptom review, and long-term safety checks. Specialist pharmacists play a central role in interpreting drug levels, managing interactions, and tailoring treatment. For some patients, a perfectly balanced dose cannot be achieved, and alternative strategies are required. This reflects biological complexity, not failure, and the overarching aim is always effective fungal control with the best possible long-term safety and quality of life.