[61] Like numerous other cardiotoxic drugs, methadone blocks the hERG K+ channel. The 2 enantiomers of methadone inhibit hERG channels with distinctive potency. Dextromethadone, that's a lot less potent as an opioid, is a lot more potent at blocking the hERG channel with an IC50 of ~twelve ?M. Levomethadone includes a lower affinity, with an IC50 o