Prednisolone vs. Prednisone vs. Dexamethasone: What Differs

Last winter your child got prednisolone liquid for a bad cough; this time the urgent care gave a single dose of dexamethasone. Or you took prednisone tablets before and now the bottle says prednisolone. All three are corticosteroids, and the differences between them are real but narrower than the names suggest.

Clinic consult room desk with an oral syringe, a small unlabeled bottle of liquid medicine and a folded patient leaflet beside a child's soft toy, mint and white tones with teal accents, no people

Quick facts

Is prednisolone a steroid? Yes, a corticosteroid. Its label calls it a synthetic adrenocortical steroid with predominantly glucocorticoid properties.
Prednisone vs. prednisolone: prednisone has to be converted by the body, largely in the liver, into prednisolone to act.
Dexamethasone: described in pediatric research as long-acting; its label says it almost completely lacks the sodium-retaining effect of hydrocortisone.
Croup: a 2023 Cochrane review found little to no difference between prednisolone and dexamethasone in croup scores at two hours.
Switching: doses are not interchangeable milligram for milligram; any change is the prescriber’s call.

Steroid questions tend to come up at awkward moments: in a pharmacy line with a coughing toddler, or reading a discharge sheet at midnight. The words “steroid,” “prednisolone” and “dexamethasone” get used loosely, and a change from one to another can feel like a downgrade or an escalation when it is often neither. This guide compares what the labels and the research actually say, then walks through the situations where each one tends to be chosen.

Three corticosteroids compared

All three drugs mimic cortisol, the hormone made by the adrenal glands, and all three are used mainly to calm inflammation and immune overreaction. Their prescribing information covers a similar list of conditions, from severe allergic states and asthma to rheumatic, skin and bowel diseases. Where they differ is in how the body handles them, how strong each milligram is, and how long the effect lasts.

Feature	Prednisolone	Prednisone	Dexamethasone
Active as swallowed?	Yes	No: converted by the body, largely in the liver, into prednisolone	Yes
Salt and water (mineralocorticoid) effect	“Slight mineralocorticoid activity” per label	Label groups it with synthetic analogs used mainly for anti-inflammatory effect	“Almost completely lacks the sodium-retaining property of hydrocortisone” per label
Relative strength per milligram	Stronger than hydrocortisone	Broadly similar to prednisolone	Much stronger per milligram than either
Duration	Plasma half-life 2 to 4 hours per label	Acts as prednisolone once converted	Described as long-acting in pediatric studies
Common US forms	Oral solution, orally disintegrating tablets, eye drops	Tablets, delayed-release tablets, oral solution	Tablets, oral concentrate, injection, eye and ear products

The strength row is deliberately qualitative. A prednisone delayed-release label includes a corticosteroid comparison chart written for prescribers. It treats prednisone and prednisolone as broadly similar per milligram and lists dexamethasone at a far smaller milligram amount, and it adds that those relationships apply only to oral or intravenous use. The Pred Forte eye-drop label describes prednisolone acetate as having 3 to 5 times the anti-inflammatory potency of hydrocortisone by weight. None of this tells you how to swap one for another. Prescribers also weigh the condition, the form, the length of the course and the person’s other health problems.

Corticosteroid, not anabolic steroid

“Steroid” covers two unrelated groups of medicines. Corticosteroids such as prednisolone copy cortisol and reduce inflammation. Anabolic-androgenic steroids, which the National Institute on Drug Abuse describes as synthetic substances similar to the male sex hormone testosterone, are the ones linked with muscle building and misuse in sport. A short prednisolone course for croup or asthma is not a performance drug, and it does not build muscle.

Prednisone and prednisolone: one step apart

The two names differ by a few letters, and so do the molecules. Prednisone is the inactive partner: the body converts it into prednisolone, a step that depends mostly on the liver. A 1980 study in Gut of 14 people with cirrhosis (Impaired conversion of prednisone to prednisolone in patients with liver cirrhosis) found that, after oral prednisone, people with severely impaired liver function had blood prednisolone levels only 53% of those seen in people with slightly impaired function, while levels after prednisolone itself did not depend on liver function. A separate 1978 study in the same journal found that prednisone was effectively absorbed and converted in both healthy volunteers and people with chronic active liver disease, so the picture depends on how severe the liver problem is.

For most people with healthy livers, the practical differences are about form and taste. Prednisolone is widely available as an oral solution and as orally disintegrating tablets, which is why children often get it. The prednisolone sodium phosphate oral solution label describes prednisolone as rapidly and well absorbed. It notes that the solution produces a 14% higher peak level, reached 20% faster, than tablets, and gives a plasma half-life of 2 to 4 hours. Dissolving tablets are another option. The Orapred ODT label reports that, in 21 adult volunteers given the same prednisolone amount, the orally disintegrating tablet and a prednisolone oral solution produced comparable blood levels. A change from liquid to a dissolving tablet is therefore mostly about convenience and taste, though the prescriber and pharmacist still set the amount. Liquid prednisolone has its own measuring pitfalls, which our guide to prednisolone for children and measuring liquid covers.

Where dexamethasone is different

Dexamethasone stands out for two reasons. The first is its salt-and-water profile. A dexamethasone tablet label states that, at equipotent anti-inflammatory doses, dexamethasone almost completely lacks the sodium-retaining property of hydrocortisone. The prednisolone label, by contrast, says prednisolone has slight mineralocorticoid activity that can cause sodium retention.

The second is duration. A 2014 meta-analysis in Pediatrics (Keeney and colleagues) lists a longer half-life, allowing a shorter course, as a potential advantage of dexamethasone. Because each milligram is so much stronger, the amount in a dose looks small next to a prednisolone dose. That small number does not mean a weaker treatment.

Croup: why one dose of dexamethasone is common

Croup is a viral swelling of the upper airway that causes a barking cough and noisy breathing. Steroids are standard care. The 2023 update of the Cochrane review Glucocorticoids for croup in children included 45 randomized trials with 5,888 children. Compared with placebo, glucocorticoids may reduce croup scores at two, six and 12 hours, though the authors rated that evidence low certainty.

On the head-to-head question, the review found little to no difference between prednisolone and dexamethasone in croup score at two hours, rated high certainty and based on one trial of 1,231 children. It also found that dexamethasone probably reduced return visits or readmissions; the risk ratio was 0.55, with a confidence interval of 0.28 to 1.11 that crosses no effect. A 2018 review in American Family Physician (Croup: Diagnosis and Management) recommends corticosteroids for croup of any severity. It calls dexamethasone the preferred corticosteroid because it is given as a single dose, and cites a community trial that found no difference between single-dose dexamethasone and three daily doses of prednisolone in mild to moderate croup. The AFP page itself notes that a newer article is available.

The same review reported that dexamethasone was linked with a 28% reduction in the use of extra steroid doses as additional treatment, based on two trials with 926 children. Taken together, the head-to-head data point to similar short-term relief, with some signs favoring dexamethasone on return visits and extra treatment, rather than a large gap between the two.

So a child who got prednisolone last time and dexamethasone this time has most likely been treated in line with the evidence both times. The choice often comes down to a single visit dose versus several days of liquid at home.

Asthma flares in children

For asthma attacks, both drugs are used. A 2025 meta-analysis in the Journal of Asthma (dexamethasone versus prednisone/prednisolone in pediatric asthma exacerbations) pooled 16 randomized trials. It found no significant differences in hospitalization, ICU admission, relapse, readmission or length of stay, while dexamethasone lowered the risk of vomiting. The 2014 Pediatrics meta-analysis reached a similar conclusion: fewer children on dexamethasone vomited, and relapse rates did not differ significantly. The authors suggested single or two-dose dexamethasone regimens as a viable alternative to five-day prednisone or prednisolone courses.

Vomiting matters more than it sounds. A child who throws up a dose of a bitter liquid may not get the treatment, and a parent then faces a hard decision about whether to repeat it. That is a question for the prescriber or pharmacist, not something to guess at.

Adults: prednisone or prednisolone tablets

In US adult practice, prednisone tablets are the more familiar product, but prednisolone works the same way once the conversion step is done. A change from one to the other can reflect what the pharmacy stocks, a need for a liquid or dissolving tablet, or liver disease. Ask why the product changed and whether the new instructions differ. Do not adjust the amount yourself.

Eye drops: a different setting

Prednisolone acetate eye drops act locally in the eye, and their risks, such as raised eye pressure and infection, differ from those of a swallowed course. Our article on prednisolone eye drops covers them, so they are not repeated here.

Side effects and stopping

Prednisolone labels list effects such as mood swings, insomnia, increased appetite, high blood sugar and nausea, and the other two carry similar class warnings. Longer courses bring the risk of adrenal suppression, which is why stopping after extended use needs a plan. Our guides to prednisolone side effects on short courses and corticosteroid side effects and safe stopping go deeper. If you want to know when to expect improvement, see how long prednisolone takes to work.

What to tell the pharmacist

Which steroid you or your child had last time, and whether the name or form has changed.
Any liver disease, diabetes, high blood pressure or heart failure.
Whether a previous dose was vomited or refused.
Other medicines, including ibuprofen or other anti-inflammatories, and any recent vaccines.
For a child, the current weight, and which measuring device you have at home.
How long the steroid has been taken in the past year, so the pharmacist can flag repeated courses.

Sources

Evidence checked November 2, 2026. Pediatric steroid choices depend on the child’s condition and history; ask the prescriber about any change.