BUDESONIDE
Clinical safety rating: safe
Animal studies have demonstrated safety
Budesonide is a corticosteroid with potent glucocorticoid activity. It binds to the glucocorticoid receptor, leading to modulation of gene expression and suppression of inflammation by inhibiting pro-inflammatory cytokines and leukocyte migration.
| Metabolism | Primarily metabolized by CYP3A4 (liver and intestinal mucosa) to inactive metabolites. |
| Excretion | Primarily hepatic metabolism via CYP3A4; metabolites excreted in feces (~60%) and urine (~10-15%). Renal excretion of unchanged drug is negligible (<2%). |
| Half-life | 2-3.6 hours (terminal elimination half-life); due to high hepatic clearance, systemic half-life is short, limiting systemic exposure. |
| Protein binding | 85-90% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | 2.7-4.5 L/kg; indicates extensive tissue distribution and high lipophilicity. |
| Bioavailability | Inhaled: 10-20% (lung deposition and absorption). Intranasal: ~34% (first-pass metabolism reduces systemic bioavailability). Oral: <10% (extensive first-pass metabolism). Topical: <1% (minimal percutaneous absorption). |
| Onset of Action | Inhaled: 24 hours for improvement in asthma symptoms. Intranasal: 10-12 hours for rhinitis symptoms. Oral (ileal-release): 2-8 days for Crohn's disease. Topical: 1-2 weeks for atopic dermatitis. |
| Duration of Action | Inhaled: 12-24 hours with twice-daily dosing. Intranasal: 24 hours with once-daily dosing. Oral: up to 8 weeks for Crohn's disease maintenance. Topical: varies with formulation; typically twice-daily application. |
Inhaled: 400-800 mcg/day in 2 divided doses for asthma; oral controlled ileal release: 9 mg once daily for Crohn's disease; intranasal: 256 mcg/day in 2 sprays per nostril once daily for allergic rhinitis.
| Dosage form | CAPSULE, DELAYED RELEASE |
| Renal impairment | No dosage adjustment required for renal impairment. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: avoid use or reduce dose by 75%. |
| Pediatric use | Inhaled: 200-400 mcg/day in 2 divided doses for children 6-12 years, 100-200 mcg/day for children under 6 (nebulized); oral: 9 mg once daily for children ≥8 years with Crohn's disease; intranasal: 64-128 mcg/day for ages 6-12, 32-64 mcg/day for ages 2-5. |
| Geriatric use | No specific dose adjustment; monitor for adrenal suppression and osteoporosis risk with long-term use. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
No significant drug interactions Systemic absorption can occur with extensive use.
| Breastfeeding | Budesonide is excreted into human breast milk in very low amounts; the estimated infant daily dose is less than 1% of the maternal weight-adjusted dose. The milk-to-plasma ratio is approximately 0.5. No adverse effects on the nursing infant have been reported. It is considered compatible with breastfeeding. |
| Teratogenic Risk | Inhaled budesonide, based on large cohort studies, does not show a significant increase in major congenital malformations, including orofacial clefts, when used at recommended doses during the first trimester. Second and third trimester use is not associated with adverse fetal effects. Systemic exposure is low, but high doses or prolonged use may theoretically cause fetal growth restriction. Overall, budesonide is considered low risk in pregnancy. |
■ FDA Black Box Warning
There is no black box warning for budesonide.
| Common Effects | Skin atrophy |
| Serious Effects |
["Hypersensitivity to budesonide or any component of the formulation","Status asthmaticus or acute asthma exacerbation (for inhalation route)","Systemic fungal infections (for oral formulations)","Active infections (may require cautious use)"]
| Precautions | ["May cause hypothalamic-pituitary-adrenal (HPA) axis suppression, especially at high doses or prolonged use","Increased risk of infections due to immunosuppression","Monitor for growth suppression in pediatric patients","May cause osteoporosis with long-term use","May exacerbate or mask infections","Monitor for corticosteroid side effects such as hypercorticism and adrenal insufficiency","Co-administration with strong CYP3A4 inhibitors (e.g., ketoconazole) may increase systemic exposure"] |
| Food/Dietary |
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| Fetal Monitoring | Monitor maternal asthma control and growth parameters (fundal height, ultrasound) if prolonged high-dose use. Assess for signs of adrenal suppression if systemic absorption is suspected. No specific fetal monitoring required beyond standard prenatal care. |
| Fertility Effects | No evidence of impaired fertility in animals or humans at therapeutic doses. Budesonide does not affect ovulation or spermatogenesis at standard inhaled doses. |
| Grapefruit juice increases systemic exposure; avoid concurrent consumption. No other significant food interactions. |
| Clinical Pearls | Budesonide is a potent glucocorticoid with high first-pass metabolism, minimizing systemic bioavailability; use for mild-to-moderate Crohn's disease (ileal/right colon) and collagenous colitis. Inhaled budesonide is preferred for asthma maintenance due to lower oral corticosteroid side effects. Nebulized budesonide can be used for croup. Monitor for adrenal suppression during prolonged use; taper when discontinuing. Not effective for acute asthma exacerbations. |
| Patient Advice | Rinse mouth after inhaled use to prevent oral candidiasis. · Take controlled ileal-release capsules whole on an empty stomach. · Do not stop suddenly; follow doctor's tapering schedule. · Report signs of infection, mood changes, or vision problems. · Carry medical alert if on long-term therapy. |