Calls to poison control centers involving energy drinks are spiking. Overdoses create irregular heartbeats and mood changes. Dr Shawn Varney, who heads the South Texas poison center, says overdoses are not deadly in most cases. But, he warns that kids with underlying health conditions are at risk of serious problems. Newly released data shows that calls for energy drinks spiked 20 percent last year. About half were unintentional chugs, with kids mistaking them for regular sodas.