Answer
Beta-blockers, including eye drops, can weaken or inhibit the effect of formoterol in Symbicort Turbohaler, so they should not be used together unless there are compelling reasons.
Sources for this answer
- Symbicort Turbohaler 100/6, Inhalation powder.AstraZeneca UK Limited · emc · SmPC §4.5 Interaction with other medicinal products · Version 31Document updated
Sources checked