1. Clinical Overview
Deflazacort is a synthetic, heterocyclic glucocorticoid of the oxazoline class. It is a prodrug that is rapidly hydrolyzed in vivo to its active metabolite, 21-desacetyl deflazacort. It possesses potent anti-inflammatory and immunosuppressive properties, with a claimed lower incidence of certain adverse effects (like weight gain, hypertension, and glucose intolerance) compared to equipotent doses of prednisone, though this remains a subject of clinical debate. It is widely used in India for managing various inflammatory and autoimmune conditions.
| Onset | Duration | Bioavailability |
|---|---|---|
| Therapeutic effects are typically observed within 1-2 hours of oral administration. | Approximately 24-36 hours, allowing for once-daily dosing. | Approximately 70-80% following oral administration. |
2. Mechanism of Action
Deflazacort, via its active metabolite, binds to the cytosolic glucocorticoid receptor (GR). The drug-receptor complex translocates to the nucleus, where it modulates gene transcription. It increases the synthesis of anti-inflammatory proteins (like lipocortin-1) and decreases the synthesis of pro-inflammatory proteins (like cytokines, chemokines, adhesion molecules, and inflammatory enzymes such as COX-2). It also has profound effects on carbohydrate, protein, and fat metabolism, and influences immune cell function.
3. Indications & Uses
- Rheumatoid Arthritis
- Systemic Lupus Erythematosus (SLE)
- Polymyositis and Dermatomyositis
- Severe Allergic Conditions (refractory to conventional therapy)
- Asthma (severe, steroid-dependent)
- Nephrotic Syndrome
- Inflammatory Bowel Disease (as adjunctive therapy)
- Duchenne Muscular Dystrophy (to slow progression)
4. Dosage & Administration
Adult Dosage: Initial dose varies by condition: Typically 24mg to 120mg per day in single or divided doses. For maintenance, the lowest effective dose should be used, often tapered to 6mg to 24mg daily.
Administration: Administer orally, preferably in the morning with food to minimize GI upset. Tablets should be swallowed whole with a glass of water. Do not crush or chew unless specified (some brands offer dispersible tablets). For once-daily dosing, take in the morning to coincide with the body's natural cortisol rhythm and reduce insomnia.
5. Side Effects
Common side effects may include:
- Increased appetite, weight gain
- Insomnia, mood changes (euphoria, nervousness)
- Dyspepsia, abdominal discomfort
- Fluid retention, edema
- Cushingoid appearance (moon face, buffalo hump)
- Acne, hirsutism
- Increased susceptibility to infections
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Ketoconazole, Itraconazole | Potent CYP3A4 inhibitors; significantly increase deflazacort levels and effects/toxicity. | Major |
| Rifampicin, Phenytoin, Carbamazepine | Potent CYP3A4 inducers; significantly decrease deflazacort levels, reducing efficacy. | Major |
| NSAIDs (e.g., Ibuprofen, Diclofenac) | Increased risk of gastrointestinal ulceration and bleeding. | Moderate |
| Warfarin | Altered anticoagulant response (may increase or decrease INR); monitor closely. | Moderate |
| Diuretics (e.g., Furosemide, Hydrochlorothiazide) | Enhanced potassium loss, leading to severe hypokalemia. | Moderate |
| Antidiabetic drugs (Insulin, Metformin) | Corticosteroids antagonize hypoglycemic effect; increased dosage of antidiabetics may be needed. | Moderate |
| Live Vaccines (MMR, Varicella, OPV) | Risk of disseminated infection due to immunosuppression; contraindicated. | Major |
7. Patient Counselling
- DO take the medicine exactly as prescribed, at the same time each day (preferably morning).
- DO NOT stop taking the medicine suddenly. Dose must be tapered under doctor's guidance.
- DO inform all your doctors and dentists that you are taking this medicine, especially before any surgery.
- DO carry a steroid alert card or wear medical identification jewelry.
- DO NOT take any over-the-counter medicines, herbal supplements (especially licorice), or other prescriptions without consulting your doctor.
- DO take with food or milk to prevent stomach upset.
8. Toxicology & Storage
Overdose: Acute overdose is unlikely to cause acute life-threatening toxicity but would manifest as an exaggeration of known adverse effects: severe Cushingoid symptoms, hypertension, hyperglycemia, hypokalemia, fluid overload, psychosis, and profound immunosuppression.
Storage: Store below 30°C, in a cool, dry place, protected from light and moisture. Keep the container tightly closed. Keep out of reach and sight of children. Do not use after the expiry date printed on the pack.