Calcort (Deflazacort) Uses, Dosage, Side Effects, and Tapering Guide 2025 (UK)

You’ve been handed a box that says Calcort and now you’re wondering: what exactly is it, how do you take it safely, and what should you watch out for? Short answer: Calcort is deflazacort, a prescription steroid used to calm inflammation in conditions like asthma flares, arthritis, and Duchenne muscular dystrophy (DMD). It works well, but it needs handling with care-timing, tapering, infection risks, and routine checks matter. I’ll walk you through the practical bits I’d want if this were on my kitchen counter in Bristol, from how to convert doses to red flags worth acting on.

• TL;DR / Key takeaways
• Calcort = deflazacort, a corticosteroid used to reduce inflammation and dampen immune reactions; similar to prednisolone in effect.
• Common UK strengths: 6 mg and 30 mg tablets; a rough guide: 6 mg deflazacort ≈ 5 mg prednisolone (BNF equivalence).
• Take in the morning with food; never stop suddenly if you’ve been on it longer than ~3 weeks-taper with your prescriber.
• Carry an NHS Steroid Emergency Card for prolonged/regular use; flag chickenpox/shingles exposure, fever, or severe illness promptly.
• Watch for mood swings, sleep issues, rising blood sugar, infection signs, eye changes, and bone health-especially if long-term.

What Calcort (deflazacort) does and when it’s used

Calcort is the brand name for deflazacort, a glucocorticoid steroid. Think of it as a strong anti-inflammatory that also suppresses the immune system. It’s converted in the body to its active metabolite (21-desacetyldeflazacort) and then does what steroids do best: tone down the chemical signals that drive swelling, pain, and immune overactivity.

What conditions is it used for? In UK practice, prescribers use deflazacort for many of the same situations as prednisolone or prednisone, including:

• Asthma exacerbations and COPD flares.
• Rheumatologic conditions like rheumatoid arthritis flares and polymyalgia rheumatica (usually short-term or bridging therapy).
• Dermatologic and allergic conditions (e.g., severe eczema or urticaria).
• Gastrointestinal and renal inflammatory conditions (e.g., inflammatory bowel disease flares, nephrotic syndrome-specialist-led).
• Neuromuscular conditions like Duchenne muscular dystrophy (DMD)-deflazacort is commonly used here under specialist care.

How does it compare with prednisolone? Clinically, effect is very similar at equivalent doses. Many UK clinicians use a simple rule: 6 mg deflazacort ≈ 5 mg prednisolone. Some evidence (including FDA-reviewed DMD data) suggests deflazacort may cause slightly less weight gain than prednisone in certain groups, but it can be associated with cataracts more often in long-term DMD use. Your specialist will weigh these trade-offs.

What to expect symptom-wise? For inflammatory pain or breathing flares, people often notice improvement within 24-48 hours. For autoimmune conditions, a few days may be needed to settle things down. If nothing budges after 3-5 days on a reasonable dose, contact your prescriber-either the diagnosis or the dose may need a rethink.

UK availability and 2025 reality check: In the UK, deflazacort is available as tablets (commonly 6 mg and 30 mg). Supply can fluctuate; pharmacists may offer a generic deflazacort instead of a brand. The action is the same; the box design might change. Your label will say exactly what to take each day.

Source for equivalence: British National Formulary (BNF), August 2025.

Special case: Duchenne muscular dystrophy (DMD). In DMD, deflazacort is often dosed by weight-commonly around 0.9 mg/kg/day in studies and regulatory guidance (FDA-approved in the US). UK neuromuscular teams individualise this, sometimes using alternate-day or intermittent regimens to manage side effects. If you’re a parent, your hospital team will give a clear plan and growth/bone monitoring schedule.

How to take Calcort safely: dosing, tapering, and monitoring

Here’s the practical, step-by-step way to get this right.

1. Start at the prescribed dose. Your box label is king. If a doctor switches you from prednisolone to deflazacort, they’ll usually match the anti‑inflammatory effect with the 6 mg ≈ 5 mg rule.
2. Take it in the morning with food. One main morning dose (around breakfast) helps your sleep and mimics natural cortisol rhythm. Food reduces stomach upset.
3. Space doses if you’re on multiple daily tablets. If you’re on a higher regimen split morning and early afternoon, avoid evening doses unless your specialist insists.
4. Missed a dose? If it’s within a few hours, take it. If it’s late in the day, skip it and take the next dose at the usual time. Don’t double up without advice.
5. Don’t stop suddenly if you’ve been on it longer than about 3 weeks. Your adrenal glands go on “snooze mode” when they get steroid from tablets. Sudden stops can lead to adrenal insufficiency-fatigue, dizziness, low blood pressure, nausea. Always taper.
6. Carry an NHS Steroid Emergency Card. In the UK, anyone on long-term or high-dose steroids is advised to carry one. Show it to paramedics, dentists, and hospital staff. It’s now standard NHS guidance (check NHS England/MHRA updates).
7. Keep vaccines updated-but avoid live vaccines on higher doses. Inactivated jabs (like flu) are fine and recommended. Live vaccines (e.g., MMR, varicella) are usually avoided if you’re on high-dose or long-term steroids-confirm with your GP or specialist nurse.

Tapering: the bit that trips people up. There isn’t a one-size-fits-all taper, but here are safe, common patterns your clinician might adapt:

• If you’ve been on a short burst (e.g., 3-5 days for asthma), you may not need a taper at all. Follow the exact course given.
• If you’ve been on for more than 3 weeks, a gentle taper is standard. A simple rule is reduce by about 10% of the total dose every 1-2 weeks. Go slower if symptoms return.
• Converting to “pred-equivalent” can help think it through. Example: You’re on 24 mg deflazacort daily (≈ 20 mg pred). Your doctor might step down to 18 mg (≈ 15 mg pred) for 1-2 weeks, then 12 mg, 9 mg, 6 mg, and finally 3 mg before stopping. The smaller the dose, the slower the steps-this is where many people need patience.
• Morning cortisol blood tests sometimes guide very slow tapers after long courses. Your clinician will arrange this if needed.

Example conversions and scenarios:

• Asthma flare (adult): If you’d usually get prednisolone 40 mg daily for 5 days, that’s roughly deflazacort 48 mg daily for 5 days (e.g., 30 mg + three 6 mg tablets in the morning). Always follow the exact script.
• Rheumatoid arthritis flare: A common short course is pred 10-15 mg/day (so deflazacort 12-18 mg/day), then taper. Timings vary with disease activity.
• DMD child: Weight-based dosing around 0.9 mg/kg/day under specialist care; clinics track growth, blood pressure, bone density, cataracts, and glucose.

Three checklists to keep you safe:

Before you start

• Tell your prescriber about all meds and supplements, including ibuprofen, naproxen, aspirin, and herbal products.
• Mention any diabetes, high blood pressure, glaucoma, cataracts, osteoporosis risk, stomach ulcers, or mental health history.
• Ask if you need bone protection (vitamin D, calcium; sometimes a bisphosphonate) if this will be long-term.
• Sort vaccines early if you’re likely to be on high doses for months.

While you’re on Calcort

• Take it in the morning with food; consider a daily step count and protein-rich meals to protect muscle.
• Watch for infection signs: fever, chills, new cough, painful rash (especially shingles), sore throat that won’t settle.
• Log mood, sleep, appetite, and blood pressure if you have a monitor. If you have diabetes, check blood sugars more often.
• Avoid extra NSAIDs unless told (ibuprofen/naproxen)-raises stomach bleed risk.

Before stopping or stepping down

• Agree a taper plan and know what to do if symptoms rebound.
• Know the red flags for adrenal insufficiency: severe fatigue, dizziness, fainting, nausea, stomach pain-seek urgent advice.
• Keep your steroid card up to date; tell dentists and hospital teams about current dose.

A quick parent note: as a mum, I keep a sticky note on the fridge during school chickenpox waves. If your child is on steroids and there’s exposure to chickenpox or shingles, call your paediatric team the same day-post‑exposure prevention may be needed. This is standard UK practice and worth acting on fast.

Side effects, interactions, and practical checklists

Short courses are usually well-tolerated. With longer or higher doses, side effects get more likely. Here’s what to expect and how to handle them.

Common, usually reversible effects (more likely at higher doses):

• Sleep disturbance, restlessness, mood swings or anxiety.
• Increased appetite and weight gain, fluid retention (puffy face, ankles).
• Indigestion, heartburn-food helps; stomach protection may be needed for high doses or if you need NSAIDs.
• Rising blood pressure or blood sugar (can unmask diabetes).
• Acne, skin thinning or slow wound healing with long-term use.

Serious effects to flag urgently:

• Signs of infection: fever, productive cough, severe sore throat, painful rash or blisters (think shingles or chickenpox exposure).
• Severe mood changes: depression, mania, hallucinations, suicidal thoughts-this can happen even at moderate doses.
• Eye problems: new floaters, blurred vision, glare sensitivity-long courses raise cataract and glaucoma risk.
• Black stools, vomiting blood, severe stomach pain-possible bleeding ulcer.
• Symptoms of adrenal insufficiency during a taper: extreme fatigue, dizziness, nausea, low blood pressure.

Long-term risk management (months to years):

• Bone health: ask about vitamin D, calcium, resistance exercise, and whether you need a DEXA scan; bisphosphonates if at high risk. UK guidance supports proactive bone care for chronic steroid users (NICE/National Osteoporosis Guideline Group).
• Eyes: periodic eye checks if long-term; cataracts and raised eye pressure are the issues to screen.
• Metabolic health: watch blood pressure, glucose, and lipids.

Drug and food interactions to know:

• Strong CYP3A inducers (e.g., rifampicin/rifampin, carbamazepine, phenytoin, St John’s wort) can lower deflazacort levels-your dose may need adjusting.
• Strong CYP3A inhibitors (e.g., ketoconazole, itraconazole, clarithromycin) can raise levels-higher side-effect risk.
• Warfarin and other anticoagulants: steroids can alter INR-extra checks may be needed.
• Diuretics (e.g., furosemide), amphotericin B: combined low potassium risk-monitor electrolytes.
• NSAIDs (ibuprofen, naproxen, aspirin at pain doses): higher stomach bleed risk together-don’t double up without a plan.
• Grapefruit products: can affect metabolism; it’s safest to avoid when on higher or long-term doses.

Vaccines and infection risk-UK angle: The NHS and MHRA advise that people on immunosuppressive steroid doses avoid live vaccines and seek prompt care after exposures to chickenpox or measles. Inactivated vaccines (flu, COVID-19, pneumococcal) are recommended. Carrying the NHS Steroid Emergency Card is now standard practice; it tells clinicians you may need stress-dose steroids during major illness, surgery, or trauma. Your GP or specialist will advise if that applies to you.

Calcort vs prednisolone: how to choose?

• Best for: patients under specialist care who benefit from deflazacort’s profile (e.g., some DMD regimens), or those who’ve struggled on pred yet do better on an equivalent deflazacort dose.
• Not for: people who need a simple, widely stocked option where prednisolone is first-line and cheaper-many UK pathways start there.
• Trade-offs: deflazacort may mean slightly less weight gain in some settings but a higher risk of cataracts has been observed in long-term DMD cohorts. Efficacy is similar when doses are equivalent.

Sources and credibility: For dose equivalence and safe tapering principles, UK clinicians lean on the British National Formulary (BNF), NICE pathways, and MHRA Drug Safety Updates. DMD-specific evidence and dosing come from FDA/EMA reviews and neuromuscular society guidance. If your plan differs, that’s normal-specialists tailor to your condition and history.

Mini‑FAQ

• Is Calcort the same as prednisolone? No-it’s deflazacort. But at equivalent doses they work similarly. A rough match is 6 mg deflazacort ≈ 5 mg prednisolone.
• Has Calcort been discontinued in the UK? Brands and suppliers change, and pharmacies often dispense generic deflazacort. If your usual brand isn’t in stock, the pharmacist will offer an equivalent.
• How fast will it work? Many inflammatory symptoms ease within 1-2 days. If nothing improves after 3-5 days on a proper dose, call your prescriber.
• Can I drink alcohol? Light to moderate alcohol is typically okay, but alcohol plus steroids increases stomach bleed risk-especially with NSAIDs. Keep it modest.
• Can I take it with antibiotics? Most are fine, but macrolides like clarithromycin can raise steroid levels. Tell your GP you’re on deflazacort.
• Pregnancy and breastfeeding? Steroids cross the placenta and may appear in breast milk in small amounts. UK practice is to use the lowest effective dose; discuss risks/benefits with your obstetrician or GP.
• Can I crush the tablets? Check the patient leaflet and ask your pharmacist. If swallowing is hard, they may suggest a different strength or formulation.

Next steps / Troubleshooting

• If side effects hit hard in week one (severe insomnia, agitation, sky‑high sugars): call your prescriber. A dose split (morning/early afternoon), a dose reduction, or a switch may help.
• If your symptoms roar back during a taper: pause at the last dose that worked and ring your clinic. Don’t abandon the taper-adjust it.
• If you get exposed to chickenpox or shingles: same‑day call to your GP or specialist team, especially for children or anyone on higher doses.
• If you’re booked for surgery or dental work: share your steroid card. You may need extra steroid cover for the stress of the procedure-standard UK protocol.
• If pharmacy supply is patchy: ask the pharmacist to check alternatives (different brands/generics, different strengths), or request your GP to prescribe an equivalent dose using what’s in stock.
• For parents of kids on long-term steroids: keep a growth and blood pressure log, make eye checks part of your routine, and build bone-friendly habits (vitamin D, protein, weight-bearing play). Your hospital team will guide the schedule.

A quick sanity check to end: steroids like deflazacort are powerful and effective. The trick is to use the lowest dose that keeps you well, for the shortest time that does the job, with smart monitoring. That’s the balance UK guidelines recommend, and it’s what keeps people active and safe.