No Clinically Significant Drug Interaction Between OHTUVAYRE and Amiodarone
Based on the FDA drug label for OHTUVAYRE (ensifentrine), there is no documented drug interaction with amiodarone, and these medications can be used together without dose adjustment.
Pharmacokinetic Analysis
The key to understanding this interaction lies in the metabolic pathways:
OHTUVAYRE (Ensifentrine) Metabolism
- Primary metabolism: CYP2C9 (predominantly) and CYP2D6 (to a lesser extent) 1
- Does NOT inhibit: CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, or CYP3A4 at therapeutic concentrations 1
- Transporter interactions: Not a substrate of P-glycoprotein; does not inhibit P-gp, BCRP, or major uptake transporters 1
Amiodarone's Drug Interaction Profile
- Inhibits: CYP2C9, CYP2D6, and CYP3A4 pathways 2
- Inhibits: P-glycoprotein membrane transporter system 2
- Clinically significant interactions: Warfarin (doubles INR), digoxin (doubles levels), beta blockers, calcium channel blockers 2
Why No Significant Interaction Exists
The interaction is mechanistically one-directional and clinically minimal:
- While amiodarone inhibits CYP2C9 (ensifentrine's primary metabolic pathway), the FDA label only documents a modest 1.6-fold increase in ensifentrine AUC when co-administered with fluconazole (a potent CYP2C9 inhibitor) 1
- Ensifentrine does NOT inhibit any of the CYP pathways or transporters that would affect amiodarone metabolism 1
- The FDA label contains no warnings or precautions regarding amiodarone co-administration 1
Clinical Management
No dose adjustments are required when using these medications together. However, standard monitoring for amiodarone remains essential:
- Monitor heart rate closely, especially during the first week of amiodarone therapy 2
- Baseline and periodic thyroid studies, liver transaminases every 6 months 2
- Watch for bradycardia and heart block (occurs in 1-3% of patients on amiodarone) 2
Important Caveat
If a patient is on both amiodarone AND a strong CYP2C9 inhibitor (like fluconazole), there could be additive effects on ensifentrine levels, though this specific combination has not been studied. In such cases, monitor for ensifentrine-related adverse effects (though the drug has demonstrated a favorable safety profile) 3.
The combination of OHTUVAYRE and amiodarone is safe for use in COPD patients requiring both bronchodilator/anti-inflammatory therapy and antiarrhythmic management 1.