Budesonide/formoterol
Symbicort Turbuhaler · Bufomix Easyhaler · DuoResp Spiromax
Formoterol is the only long-acting β₂-agonist with onset within a few minutes, and that property is precisely what makes the combination useful both as maintenance and as reliever therapy. The product can therefore be prescribed in two entirely different ways: as a fixed dose morning and evening with a separate SABA as needed, or as maintenance-and-reliever therapy in the same inhaler. The two regimens must never be confused — this is the most common prescribing error with this drug.
With maintenance-and-reliever therapy, the patient should seek care if more than 8 inhalations per day are needed; this signals a developing exacerbation. Symbicort forte 320/9 is not approved as reliever medication. Inhaled corticosteroid must never be discontinued while LABA continues.
Dosing in adults
| Indication | Regimen | Comment |
|---|---|---|
| Asthma, fixed maintenance dose | 160/4,5 μg: 1–2 inhalations × 2, plus separate SABA as needed | the reliever is a different drug in this regimen |
| Asthma, maintenance and reliever (MART) | 160/4,5 μg: 2 inhalations/day as maintenance, plus 1 inhalation for symptoms; normally maximum 8 per day, temporarily up to 12, never more than 6 at one time | no separate SABA should be prescribed in parallel |
| Asthma, high maintenance dose | 320/9 μg: 1 inhalation × 2, if needed 2 inhalations × 2 | fixed dosing — combined with separate SABA |
| COPD | 320/9 μg: 1 inhalation × 2 | only if FEV₁ below 70 % and repeated exacerbations |
| Dose reduction | Reduce to lowest dose that keeps the patient symptom-free for 3 months | never discontinue the steroid component and keep LABA |
No established dose adjustment.
No formal dose adjustment, but budesonide exposure increases in severe hepatic impairment — use the lowest effective dose.
From 6 years: 80/4,5 μg 1–2 inhalations × 2 as fixed maintenance. Maintenance-and-reliever therapy with 160/4,5 μg approved from 12 years.
Always instruct mouth rinsing after inhalation and avoid prescribing to a patient who has not had technique and regimen demonstrated. The classic trap is a patient on MART who still has their old salbutamol prescription — this eliminates the entire point of the regimen and the steroid dose that should follow the symptoms is missing.
Pharmacokinetics
- ONSET (formoterol)
- 1–3 minutes
- DURATION (formoterol)
- 12 hours
- t½ BUDESONIDE
- 2–3 hours
- t½ FORMOTEROL
- 8–10 hours
- BIOAVAIL.
- approximately 40 % of inhaled dose systemically
- METABOLISM
- Budesonide via CYP3A4; formoterol via glucuronidation
- EXCRETION
- Renal (metabolites)
- FULL STEROID EFFECT
- after 1–2 weeks of regular use