Sentence: The hearts were treated during the whole procedure either with vehicle , 0.5 μM flecainide ( sodium channel blocker ) or 100 μM streptomycin ( here used as stretch-activated ion-channel blocker ) .
Drug combination annotation:
[{'class': 'COMB', 'spans': ['flecainide', 'streptomycin'], 'is_context_needed': True}]