Prednisolone
Is It Right for You?
A complete guide to Prednisolone — what it treats, how it works, dosages, side effects, and when a clinician may prescribe it following an online consultation.
What Is Prednisolone?
Prednisolone is a synthetic corticosteroid – a class of medication that mimics the effects of cortisol, a hormone naturally produced by the adrenal glands. It is one of the most widely used anti-inflammatory and immunosuppressive medications in clinical practice, prescribed across virtually every medical speciality for conditions driven by inflammation, autoimmune activity, or allergic responses.
Prednisolone is the active form of prednisone (which is converted to prednisolone in the liver) and has been in clinical use since the 1950s. It exerts powerful anti-inflammatory and immunosuppressive effects by suppressing the immune system's inflammatory response, making it effective for a vast range of conditions from severe allergic reactions and asthma to autoimmune diseases, inflammatory bowel conditions, and certain cancers.
It is available in tablet, soluble tablet, oral solution, and enteric-coated tablet forms for systemic use, as well as topical preparations for local application. Prednisolone is suitable for adults and children across a wide range of indications. It is available generically and under brand names including Deltacortril and Dilacort.
Prednisolone is a prescription-only medication in the UK. A licensed clinician must assess your symptoms and medical history before it can be prescribed – which can now be done quickly and conveniently through a telehealth consultation.
What Conditions Is Prednisolone Used For?
Prednisolone is prescribed across an exceptionally broad range of inflammatory, allergic, and autoimmune conditions:
short courses used to treat acute asthma exacerbations and reduce airway inflammation; long-term low-dose use in severe persistent asthma.
short courses used during acute exacerbations to reduce airway inflammation and speed recovery.
moderate to severe allergic reactions including severe urticaria, angioedema, and allergic rhinitis unresponsive to antihistamines.
Crohn's disease and ulcerative colitis; used to induce remission during flares.
reduces joint inflammation and pain during flares; used as a bridge therapy while disease-modifying drugs take effect.
prednisolone is the primary treatment for PMR, producing rapid and dramatic symptom relief.
high-dose prednisolone is the cornerstone of treatment to prevent blindness and other serious complications.
used to control disease flares and organ-threatening manifestations.
short systemic courses for severe flares unresponsive to topical treatment.
used to induce remission in certain types of kidney disease characterised by protein loss in the urine.
used as part of chemotherapy regimens for leukaemia, lymphoma, and myeloma.
early treatment with prednisolone significantly improves recovery of facial nerve function.
used to treat pulmonary and systemic sarcoidosis requiring treatment.
used as replacement therapy in patients with Addison's disease or secondary adrenal insufficiency.
used as part of immunosuppressive regimens to prevent organ rejection.
a single dose of oral prednisolone or dexamethasone is standard treatment for croup in children.
Prednisolone reduces the body's immune response, which increases susceptibility to infections. Patients on prednisolone – particularly at higher doses or for prolonged periods – should be vigilant about signs of infection and seek prompt medical attention if they develop fever, unusual symptoms, or signs of illness. Contact with individuals who have chickenpox, shingles, or measles should be reported to a clinician immediately if you are not immune, as these can be serious or life-threatening in immunosuppressed patients.
How Does Prednisolone Work?
Prednisolone is a glucocorticoid that exerts its effects by entering cells and binding to intracellular glucocorticoid receptors (GRs). The prednisolone-receptor complex then translocates to the cell nucleus, where it directly modulates gene transcription – switching on anti-inflammatory genes and switching off pro-inflammatory genes.
Anti-inflammatory effects arise from multiple mechanisms:
- Suppression of pro-inflammatory cytokines including interleukin-1 (IL-1), interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-α), and interferons
- Inhibition of phospholipase A2, the enzyme that initiates the production of prostaglandins, leukotrienes, and other inflammatory mediators
- Reduction in the production of cyclo-oxygenase-2 (COX-2), further limiting prostaglandin synthesis
- Decreased capillary permeability, reducing oedema and swelling at sites of inflammation
Immunosuppressive effects arise from:
- Inhibition of T-lymphocyte activation and proliferation
- Reduced antibody production by B lymphocytes
- Impaired migration of immune cells to sites of inflammation
- Suppression of macrophage function and antigen presentation
These broad-reaching effects on immune and inflammatory pathways explain prednisolone's remarkable efficacy across such a diverse range of conditions, as well as its significant side effect profile with prolonged use – many of which arise from the same mechanisms that make it therapeutically effective.
Dosages & Administration
The correct dose depends on the type and severity of infection, age, weight, and kidney function. Always follow your clinician's instructions. The table below is for general reference only.
Administration Tips
Take prednisolone in the morning, ideally with or shortly after breakfast. The adrenal glands naturally produce cortisol in the morning, and taking prednisolone at this time mimics this natural rhythm, reducing the suppressive effect on the body's own cortisol production and minimising sleep disturbance.
Always take with food to reduce the risk of gastric irritation, indigestion, and stomach ulcers – one of the most common side effects of prednisolone.
Enteric-coated tablets (e.g. Deltacortril EC) are designed to dissolve in the small intestine rather than the stomach, reducing gastric irritation. They should be swallowed whole and not crushed or chewed.
Never stop prednisolone suddenly if you have been taking it for more than 3 weeks, or at any dose greater than physiological replacement levels (approximately 7.5 mg daily). Abrupt withdrawal can cause adrenal insufficiency – a potentially life-threatening condition – because prolonged prednisolone use suppresses the body's natural cortisol production. The dose must always be tapered gradually under medical supervision.
Carry a steroid treatment card if you are on regular prednisolone, particularly at doses above 7.5 mg daily. This informs other healthcare providers that you are taking a corticosteroid, which is critical in emergencies.
Side Effects of Prednisolone
Short courses of prednisolone (5–7 days) at standard doses are generally well tolerated with few significant side effects. The risk of side effects increases substantially with higher doses and prolonged use. Many of the most serious side effects of prednisolone are associated with long-term use.
- Increased appetite and weight gain
- Fluid retention and bloating
- Mood changes – including irritability, euphoria, anxiety, or low mood
- Insomnia or sleep disturbance
- Indigestion, heartburn, or stomach pain
- Increased blood glucose (hyperglycaemia) – may unmask or worsen diabetes
- Acne or skin changes
- Increased sweating
- Mild increase in blood pressure
- Osteoporosis – bone thinning and increased fracture risk; bone protection (calcium, vitamin D, and bisphosphonates) is typically co-prescribed for long-term use
- Cushingoid features – weight gain (particularly central/abdominal), moon face, buffalo hump, and stretch marks (striae)
- Adrenal suppression – reduced ability of the adrenal glands to produce cortisol naturally
- Cataract and glaucoma – increased risk with prolonged use
- Muscle wasting (myopathy) – proximal muscle weakness, particularly affecting the thighs and upper arms
- Skin thinning – easy bruising, poor wound healing, and skin fragility
- Growth suppression – in children on long-term systemic corticosteroids
Patients on immunosuppressive doses of prednisolone who are not immune to chickenpox or measles are at risk of severe and potentially fatal forms of these infections. If you are on prednisolone and come into contact with someone who has chickenpox, shingles, or measles, contact your clinician immediately. Passive immunisation with varicella zoster immunoglobulin (VZIG) or measles immunoglobulin may be required urgently.
Drug Interactions
Always disclose all prescription drugs, over-the-counter medicines, vitamins, and supplements to your clinician or pharmacist before starting prednisolone.
Prednisolone suppresses the immune system and must not be given alongside live attenuated vaccines (e.g. MMR, varicella, yellow fever) as this may result in disseminated infection from the vaccine organism. Live vaccines should be administered at least 4 weeks before or 3 months after immunosuppressive doses of prednisolone.
Combining prednisolone with NSAIDs significantly increases the risk of gastrointestinal ulceration and bleeding. This combination should be avoided where possible; if both are necessary, a proton pump inhibitor (PPI) should be co-prescribed for gastric protection.
Prednisolone may enhance or reduce the anticoagulant effect of warfarin unpredictably. INR should be monitored more frequently when prednisolone is started, changed in dose, or stopped.
Prednisolone raises blood glucose levels and can significantly worsen diabetic control, requiring dose adjustments of antidiabetic medications. Blood glucose should be monitored closely when prednisolone is started or the dose is changed.
Prednisolone causes fluid retention and can raise blood pressure, potentially reducing the effectiveness of antihypertensive medications. Blood pressure should be monitored more closely during prednisolone treatment.
These drugs significantly increase the metabolism of prednisolone, reducing its blood levels and therapeutic effect. Higher doses of prednisolone may be required. Inform your clinician if you take any of these medications.
These drugs inhibit the metabolism of prednisolone, increasing blood levels and the risk of side effects. Dose reduction may be necessary.
Combined use may increase potassium loss (hypokalaemia), raising the risk of cardiac arrhythmias. Potassium levels should be monitored.
Prednisolone may reduce salicylate blood levels and increase the risk of salicylate toxicity when aspirin is stopped. Concurrent use also increases gastrointestinal side effects.
Important Warnings
If you have been taking prednisolone for more than 3 weeks, stopping abruptly can cause acute adrenal insufficiency – a potentially life-threatening condition characterised by severe fatigue, dizziness, nausea, vomiting, low blood pressure, and collapse. The dose must always be tapered gradually under medical supervision. During periods of physical stress such as illness, injury, or surgery, the dose may need to be temporarily increased (sick day rules). Always inform any treating clinician or surgeon that you are taking prednisolone.
Prednisolone suppresses immune function, significantly increasing susceptibility to bacterial, viral, fungal, and parasitic infections. Symptoms of infection may be masked or atypical in immunosuppressed patients. Any fever, unusual symptoms, or rapid deterioration in health requires prompt medical attention. Contact with chickenpox, shingles, or measles in non-immune patients must be reported to a clinician immediately.
Long-term prednisolone use (generally defined as 3 months or more at doses ≥5 mg daily) significantly increases the risk of osteoporosis and fragility fractures. Patients on long-term prednisolone should routinely be prescribed calcium and vitamin D supplementation, and bisphosphonate therapy (e.g. alendronic acid) should be considered based on fracture risk assessment. Bone density monitoring (DEXA scan) may be recommended.
Prednisolone raises blood glucose levels and can unmask previously undiagnosed diabetes or significantly worsen existing diabetic control. Blood glucose should be monitored in all patients starting prednisolone, and diabetic patients should increase their glucose monitoring frequency. Steroid-induced diabetes may require treatment with insulin or oral hypoglycaemic agents.
All patients on prednisolone at doses above physiological levels should carry a steroid treatment card at all times. This informs medical staff in emergencies that you are taking a corticosteroid and that additional stress doses of steroid may be required during illness, injury, or surgery to prevent adrenal crisis.
Prednisolone can cause significant mood changes ranging from mild euphoria and irritability to severe depression, mania, or psychosis – particularly at high doses. These effects can occur at any time during treatment. Patients with a personal or family history of psychiatric conditions should be monitored closely. If significant mood disturbance occurs, contact your clinician promptly.
Prednisolone crosses the placenta in small amounts (it is partly metabolised by the placenta, unlike betamethasone and dexamethasone). It is used in pregnancy when clinically necessary and is one of the preferred corticosteroids for maternal conditions during pregnancy. High-dose or prolonged use carries risks including intrauterine growth restriction and neonatal adrenal suppression. Prednisolone passes into breast milk in small amounts; the risk to the infant is generally considered low at standard doses. Always inform your clinician if you are pregnant or breastfeeding.
Speak to a Clinician About Treatment
Getting advice no longer means sitting in a waiting room. Through The GP Service, you can consult with a licensed clinician in minutes — from home, on your lunch break, or wherever works for you. If treatment is clinically appropriate, your clinician can issue a prescription during the consultation. A consultation does not guarantee a prescription.
The treatment you need, when you need it.
Prednisolone FAQs
Yes. A licensed clinician can assess your symptoms and medical history via a telehealth consultation and prescribe prednisolone if it is clinically appropriate. Prescriptions are typically sent to your preferred pharmacy the same day, often within minutes of your consultation.
Prednisolone works relatively quickly compared to many other anti-inflammatory medications. For acute conditions such as asthma exacerbations or severe allergic reactions, significant improvement is often noticed within 24 to 48 hours. For conditions such as polymyalgia rheumatica, the response can be dramatically rapid – often within days. For chronic inflammatory conditions, the full therapeutic effect develops over a longer period.
Yes. Prednisolone should always be taken with or shortly after food to reduce the risk of gastric irritation, indigestion, and stomach ulcers. Taking it on an empty stomach significantly increases the risk of these side effects.
The body naturally produces cortisol in the morning. Taking prednisolone at this time aligns with the body's natural hormonal rhythm, which reduces disruption to the hypothalamic-pituitary-adrenal (HPA) axis – the system that regulates the body's own cortisol production. It also reduces the likelihood of sleep disturbance caused by the stimulating effects of corticosteroids.
Short courses of prednisolone (typically 5 to 10 days) at standard doses are generally well tolerated. You may notice increased appetite, mild mood changes, difficulty sleeping, or a transient rise in blood sugar, but serious long-term side effects such as osteoporosis, adrenal suppression, and Cushingoid features are associated with prolonged use rather than short courses. Your clinician will prescribe the shortest effective course.
Long-term prednisolone use suppresses the body's own production of cortisol by the adrenal glands. If prednisolone is stopped suddenly, the adrenal glands may not be able to produce sufficient cortisol to meet the body's needs, potentially causing adrenal insufficiency or crisis. Gradual tapering allows the adrenal glands time to recover their natural function.
Yes. Prednisolone stimulates appetite and causes fluid retention, both of which contribute to weight gain. With longer-term use, it can also cause a redistribution of body fat – particularly increased abdominal and facial fat (moon face, central obesity) – known as Cushingoid features. These changes are more pronounced with higher doses and longer duration of treatment.
Yes. Prednisolone raises blood glucose levels by promoting gluconeogenesis in the liver and reducing insulin sensitivity in peripheral tissues. In patients with diabetes, this can significantly worsen glycaemic control. In patients without diagnosed diabetes, prednisolone can unmask glucose intolerance or steroid-induced diabetes. Blood glucose monitoring is important for all patients starting prednisolone.
A steroid treatment card is a card issued to patients taking regular systemic corticosteroids. It informs other healthcare providers – including in emergencies – that you are taking a steroid and that additional steroid cover may be required during illness, injury, or surgery to prevent adrenal crisis. If you are on regular prednisolone, your clinician or pharmacist should provide you with one.
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Yes. Prednisolone is used in children for a range of conditions including asthma, croup, nephrotic syndrome, and inflammatory conditions. Paediatric doses are carefully calculated based on weight and the specific condition being treated. Long-term use in children requires careful monitoring of growth, bone density, and adrenal function.