Budesonide
Also known as: Entocort EC · Pulmicort · Rhinocort · Benacort · Budelin · Budenofalk · Cortiment · Budesonidum
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
This dose is based on body surface area (mg/m²). Convert body weight to body surface area before dosing.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Inflammatory Bowel Disease (IBD) (Clinical Pearl) | 1 - 3 mg/m2 or 1 - 3 mg/dog | PO | q24h | Chronic management; taper to lowest effective dose | 🌍 EU |
- Inflammatory Bowel Disease (IBD) (Clinical Pearl): Do not crush or chew capsules.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Inflammatory Bowel Disease (IBD) (Clinical Pearl) | 1 mg/cat | PO | q24h | Chronic management; taper to lowest effective dose | 🌍 EU |
| Feline Asthma (Clinical Pearl) | 100 - 400 µg (1-2 puffs) | Inhalation | q12h | Chronic management | 🌍 EU |
- Inflammatory Bowel Disease (IBD) (Clinical Pearl): May be compounded if standard sizes are too large, though this alters the enteric coating.
- Feline Asthma (Clinical Pearl): Administer via a feline-specific spacer mask (e.g., AeroKat).
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Budesonide is a locally acting, highly potent glucocorticoid (approximately 15 times more potent than prednisolone) with weak mineralocorticoid activity.
- Targeted Delivery: Oral formulations are typically enteric-coated (e.g., Entocort EC®) to delay dissolution until the drug reaches the duodenum. This allows the medication to exert concentrated, topical anti-inflammatory action directly within the intestines.
- Reduced Systemic Effects: While absorbed into the portal circulation, budesonide undergoes extensive first-pass hepatic metabolism. The liver clears the vast majority of the drug before it reaches systemic circulation, significantly reducing the risk of classic systemic steroid side effects (such as polyuria, polydipsia, and polyphagia).
- Clinical Utility: Primarily used off-label in veterinary medicine for Inflammatory Bowel Disease (IBD) in dogs and cats that are either refractory to, or intolerant of, traditional systemic corticosteroids.
- Cost & Formulation: Expense can be a limiting factor, and because human capsules are often too large for small veterinary patients, the drug frequently requires compounding into smaller dosage strengths.
Mechanism of action
Budesonide diffuses across cell membranes and binds with high affinity to cytosolic glucocorticoid receptors (GR).
- The receptor-ligand complex translocates to the nucleus → binds to glucocorticoid response elements (GREs) on DNA → alters gene transcription.
- Anti-inflammatory pathway: Induces the production of lipocortin-1 (annexin-1) → inhibits phospholipase A2 → blocks the release of arachidonic acid from membrane phospholipids → decreases the synthesis of potent inflammatory mediators (prostaglandins and leukotrienes).
- Despite its high first-pass metabolism, it still causes significant suppression of the hypothalamic-pituitary-adrenal (HPA) axis.
Safety & warnings
Contraindications
- Hypersensitivity to budesonide
- Patients with active GI ulcers
- Active systemic infections
- Diabetes mellitus
- Cataracts
Adverse effects
- Steroid hepatopathy
- HPA-axis suppression
- Hyperadrenocorticism (rare, but risk increases with hepatic dysfunction)
Precautions
Use with caution in patients with moderate to severe hepatic dysfunction, as they are more likely to develop signs of hypercorticism. Because budesonide suppresses the HPA-axis, animals undergoing stressful procedures (such as surgery) should be considered for exogenous systemic steroid administration. FDA Category C for pregnancy; demonstrated to be embryocidal and teratogenic in rats and rabbits.
Drug interactions
May decrease the hepatic metabolism of budesonide, leading to increased systemic blood levels and a higher risk of glucocorticoid adverse effects.
May increase gastric pH, potentially causing premature dissolution of the enteric coating and reducing the drug's targeted efficacy in the intestines.
Inhibits CYP3A4, significantly increasing systemic budesonide levels and risk of toxicity
Inhibits CYP3A4, increasing systemic budesonide levels
Inhibits CYP3A4, potentially increasing budesonide levels
Increased risk of gastrointestinal ulceration and bleeding
Monitoring
- Resolution of clinical signs of IBD (vomiting, diarrhea, weight loss)
- Liver enzymes (ALP, ALT) for potential steroid hepatopathy
- Clinical signs of hyperadrenocorticism (PU/PD/PP, panting, alopecia)
Pharmacokinetics
Half-life
Absorption
Bioavailability is 10-20% in dogs due to a high first-pass effect. In humans, food may delay absorption but does not impact the total amount absorbed.
Distribution
Mean volume of distribution in humans ranges from 2.2-3.9 L/kg.
Metabolism
Undergoes extensive first-pass metabolism in the liver, which significantly reduces systemic bioavailability.
Elimination
Completely metabolized; metabolites are excreted in the feces and urine. Clearance in dogs is 2.2 L/hr/kg.
Overdose
Acute oral overdoses are unlikely to be of much clinical concern, though massive overdoses may warrant gut evacuation. The lethal dose in mice is reported to be 200 mg/kg.
Available products
Formulations
- Enteric-coated capsules
- Inhalation suspension
- Nasal spray
- Compounded oral formulations
Human-labeled
- Entocort EC® (capsules)
Regulatory status
Human authorized products used off-label under the cascade.
Human authorized products used off-label under the cascade.
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store at room temperature in tight, light-resistant containers. Protect from moisture.
Client information
Important: Do not crush or allow your pet to chew the enteric-coated capsules. The special coating must remain intact to deliver the medication directly to the intestines.
- Administration: Can be given with or without food. If your pet has a sensitive stomach, giving it with food may help.
- Side Effects: While much less common than with standard systemic steroids (like prednisone), watch for increased thirst, increased urination, increased appetite, or excessive panting.
- Stress and Surgery: Because this drug can suppress the body's natural stress response, inform your veterinarian that your pet is taking budesonide before any surgery, dental procedure, or major stressful event. They may need a temporary dose of a different steroid to help them cope with the stress.
- Compounding: Because human capsules are often too large for small pets, your veterinarian may have this medication specially compounded at a pharmacy to ensure accurate dosing.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.