Trilogy Elliptic to Symbicort Equivalence
Trilogy Elliptic 100/6.2/25 (fluticasone furoate 100 mcg/umeclidinium 62.5 mcg/vilanterol 25 mcg) cannot be directly converted to Symbicort (budesonide/formoterol) as they are fundamentally different medication classes with distinct mechanisms and indications. Trilogy Elliptic is a triple therapy inhaler containing an ICS/LAMA/LABA combination primarily indicated for COPD, while Symbicort is an ICS/LABA combination indicated for asthma and COPD 1, 2.
Key Differences That Prevent Direct Equivalence
Medication composition:
- Trilogy Elliptic contains fluticasone furoate (ICS) + umeclidinium (long-acting muscarinic antagonist/LAMA) + vilanterol (LABA) 1
- Symbicort contains budesonide (ICS) + formoterol (LABA) only 1, 3
The presence of umeclidinium (anticholinergic) in Trilogy Elliptic represents an entirely different therapeutic component not present in any Symbicort formulation 1.
ICS Component Comparison
If attempting to match only the corticosteroid component:
- Fluticasone furoate 100 mcg in Trilogy Elliptic is roughly equivalent to budesonide 320-640 mcg in terms of potency 1
- This would suggest Symbicort 160/4.5 mcg (2 inhalations twice daily = 640 mcg budesonide total daily) as the closest ICS-equivalent strength 1
Critical Clinical Considerations
LABA differences matter significantly:
- Vilanterol (in Trilogy Elliptic) has a slower onset of action and cannot be used for acute symptom relief 2
- Formoterol (in Symbicort) has rapid onset within 1 minute, allowing its use in SMART protocols for both maintenance and rescue 2, 3, 4
The missing LAMA component:
- Switching from Trilogy Elliptic to Symbicort eliminates the anticholinergic bronchodilation provided by umeclidinium 1
- If the patient requires triple therapy, a separate LAMA inhaler (tiotropium, umeclidinium) would need to be added to Symbicort 1
Recommended Approach
For patients requiring conversion:
- Determine the clinical indication - If COPD with triple therapy requirement, Symbicort alone is inadequate; add separate LAMA 1
- Start with Symbicort 160/4.5 mcg, two inhalations twice daily (total daily: 640 mcg budesonide/18 mcg formoterol) 1
- Assess control after 2-6 weeks and adjust accordingly 1
- Consider whether SMART protocol is appropriate if the indication is asthma, as this allows formoterol's rapid-acting properties to be utilized for both maintenance and relief 2, 4
Common pitfall: Assuming all ICS/LABA combinations are interchangeable - they are not, particularly regarding LABA onset of action and suitability for rescue use 2, 5.