Budesonide
Pulmicort / Rhinocort / Symbicort (with formoterol) / QVAR (beclomethasone — different)
corticosteroid inhaledinhaled (DPI — Flexhaler) · inhaled (SVN) · nasal spray · oral (enteric-coated)Onset: Hours to days (anti-inflammatory effect) — not for acute useDuration: Sustained with regular use
Mechanism of Action
Synthetic glucocorticoid. Binds intracellular glucocorticoid receptors → nuclear translocation → reduces transcription of inflammatory genes (cytokines, chemokines). Decreases airway eosinophilia, mast cell activity, and mucus production.
Dosing
Adult
Pulmicort Flexhaler DPI: 180–360 mcg BID (asthma). Max 720 mcg BID. SVN: 0.25–1 mg BID
Pediatric
SVN: 0.25–0.5 mg BID (12 months to 8 years). Flexhaler: 180 mcg BID (≥6 years)
Neonatal
Not typically used in neonates; racemic epinephrine preferred for croup in infants
Croup: 2 mg via SVN as single dose; may repeat in 12 hours
Indications
- Asthma maintenance (all severity levels)
- COPD (moderate-severe, adjunct to LABA/LAMA)
- Croup (nebulized) — reduces subglottic edema
- Eosinophilic esophagitis (swallowed formulation)
Contraindications
- Acute bronchospasm (not a rescue drug)
- Systemic fungal infections
- Hypersensitivity to budesonide
Side Effects
- Oropharyngeal candidiasis (thrush)
- Dysphonia (hoarseness)
- Cough
- Adrenal suppression (high doses, long term)
- Growth retardation (children — high doses)
- Osteoporosis (long term, high doses)
Monitoring Parameters
- Oral cavity for candidiasis
- Growth velocity in children
- HPA axis function with high doses
- Bone density (long-term therapy)
- Asthma control and exacerbation rate
Drug Interactions
- CYP3A4 inhibitors (ketoconazole, ritonavir) — increase budesonide levels
- Additive adrenal suppression with systemic corticosteroids
Clinical Pearls
- Rinse mouth and gargle after every dose to prevent oropharyngeal candidiasis
- Takes days to weeks for full anti-inflammatory effect — not a rescue inhaler
- Combined with formoterol in Symbicort
- Preferred ICS in pregnancy (most safety data)
- High first-pass metabolism reduces systemic bioavailability after swallowing
- Nebulized form used for croup — reduces need for epinephrine and hospitalization
Mnemonic
💡 Bud-esonide: BUD = Breathe Underwater Deeper (anti-inflammatory, long-term)
NBRC High-Yield
- ICS — must rinse mouth after use to prevent thrush
- NOT for acute bronchospasm — takes days for anti-inflammatory effect
- Preferred ICS in pregnancy
- Nebulized budesonide for croup: 2 mg single dose SVN
- Thrush and dysphonia are the most common side effects
- Combined with formoterol = Symbicort