Ectopic expression of the voltage-dependent K+ channel Eag1 (or Kv10.1) is associated with ∼70% of human cancers and, reciprocally, Kv10.1 channel inhibition hinders tumors growth. In agreement with its particular role in cancer, recent reports have shown that Kv10.1 presents structural, and functional, characteristics that depart from those common to canonical, Shaker-related, K+ channels. Amiodarone is an anti-arrhythmic drug thought to bind within the pore of canonical K+-channels. In this work we studied the interaction of amiodarone with Kv10.1. The drug affects these channels at nanomollar concentrations, and that amiodarone exerts a dual effect on Kv10.1, depending on the time-window of channel activity and on the resting membrane potential from which channels are activated. On a time scale of hundreds of milliseconds to seconds amiodarone induces a slow channel inhibition (or apparent inactivation) that reduces the K+ conductance. On the other hand, looking at the first milliseconds of channel activity, we observed that, surprisingly, amiodarone accelerates the kinetics of K+ current activation. As a result of this, the initial K+ current surge of Ad-modified channels may transiently surpass IK of unmodified channels, depending on the resting membrane potential from which the currents are activated. The latter is observed in external solutions containing either zero or 2 mM external Mg2+ ions. These observations suggest that amiodarone binds to the voltage-sensor module, and hence modifies conformational changes of Kv10.1 channels.