Pharmacology · Corticosteroids (glucocorticoids)
Prednisone !
An oral corticosteroid prodrug: the liver turns it into prednisolone. Widely used for asthma, rheumatic and autoimmune diseases.
Updated 2026-11-01
The figure shows cortisol (hydrocortisone) in the ligand-binding pocket of the human glucocorticoid receptor; prednisolone, the active form of prednisone, binds the same pocket.
Mechanism of action
Prednisone itself is inactive. In the liver, 11β-hydroxysteroid dehydrogenase converts it to prednisolone, which binds the glucocorticoid receptor. The receptor complex enters the nucleus, switches on anti-inflammatory genes and represses NF-κB and AP-1, lowering cytokines and immune cell activity. It has intermediate duration and some salt-retaining effect.
- The liver converts prednisone into active prednisolone
- Prednisolone binds the glucocorticoid receptor and enters the nucleus
- Anti-inflammatory genes on; NF-κB and AP-1 repressed
- Less inflammation and immune activity
Pharmacokinetics
- Absorption
- Given by mouth, usually with food
- Metabolism
- Prodrug: activated to prednisolone in the liver; severe liver disease can blunt activation
- Half-life
- Intermediate-acting glucocorticoid
Indications
- Asthma and COPD exacerbations Asthma →
- Rheumatoid arthritis and other rheumatic diseases Rheumatoid arthritis →
- Systemic lupus erythematosus Systemic lupus erythematosus →
- Inflammatory bowel disease flares Crohn disease →
- Multiple sclerosis exacerbations Multiple sclerosis →
- Lymphomas and leukaemias, as part of combination regimens
Adverse effects
Common
- Insomnia and mood swings
- Increased appetite, weight gain and central fat
- Hyperglycaemia
- Thin skin, stretch marks and slow wound healing
- Muscle weakness
Contraindications
- Systemic fungal infections
- Hypersensitivity to the product
- Live or live attenuated vaccines during immunosuppressive doses
Key interactions
- CYP3A4 inducers (rifampicin, phenytoin, carbamazepine, barbiturates)
- Faster clearance and a weaker corticosteroid effect
- Strong CYP3A4 inhibitors (ketoconazole)
- Higher corticosteroid levels and more side effects
- Aspirin and other NSAIDs
- Higher risk of gastrointestinal ulcer and bleeding
- Potassium-depleting drugs (loop or thiazide diuretics, amphotericin B)
- Hypokalaemia; with digoxin, more risk of arrhythmia
- Warfarin
- The anticoagulant response changes; INR is checked more often
What is monitored
- Blood glucose
- Blood pressure and weight
- Potassium
- Signs of infection
- Eye pressure and bone density with long use
Administration and safety
- Given by mouth with food; delayed-release forms are swallowed whole
- A single morning dose follows the natural cortisol rhythm and causes less insomnia
- Long courses are tapered, not stopped suddenly
Nursing care
- Check glucose, especially in people with diabetes; corticosteroids raise it
- Watch for infection: fever and other signs may be blunted
- Watch mood and sleep; report agitation, depression or confusion
- Teach that a long course is not stopped suddenly; it is tapered under medical supervision
- Ask about black or tarry stools, a sign of digestive bleeding
Pregnancy and breastfeeding
Used in pregnancy when the benefit justifies it; newborns of mothers on substantial doses are watched for adrenal insufficiency.
Test yourself
Think of the answer, then tap the question to see it.
Prednisone is a prodrug. What is its active form and where is it made?
Prednisolone, made in the liver by 11β-hydroxysteroid dehydrogenase.
Why is a once-daily prednisone dose usually given in the morning?
It matches the natural morning cortisol peak, causes less insomnia and suppresses the HPA axis less than evening doses.
Which vaccines are avoided during immunosuppressive doses of prednisone?
Live or live attenuated vaccines, because the weakened immune system may let the vaccine organism replicate.
Related drugs
Related conditions
← Back to the class: Corticosteroids (glucocorticoids)
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Prednisone: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2024); DailyMed - PREDNISONE tablet (DailyMed (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); Farmacología básica y clínica (Katzung), 16.ª ed., cap. 39 (McGraw Hill, 2025).
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Representative model, for educational purposes only.