Evaluation of the Potential Effect of Iptakalim Hydrochloride on the QT Interval in Single- and Multiple-Ascending-Dose Studies Using Concentration-QTc Analysis.

Cardiotoxicity has been one of the most common causes of withdrawal of drugs from the market, and prolongation of the QT interval is one of the manifestations of drug cardiotoxicity. Iptakalim hydrochloride (ITKL) is a selective ATP-sensitive potassium channel opener used to treat hypertension. It is crucial to assess the risk of cardiac repolarization of ITKL in clinical trials. This study was conducted to determine the effect of ITKL on corrected QT (QTc) interval. A randomized, double-blind, placebo-controlled single- and multidose regimen was carried out to investigate the QTc and ITKL concentration correlation. ITKL was administered at doses of 5, 10, 15, and 20 mg with single oral administration and 10 and 20 mg with multiple oral administration, along with placebo, in 83 healthy subjects. Electrocardiograms (ECGs) and blood samples were collected on a preset time schedule. A ΔΔQTcF effect above 10 milliseconds was excluded at all observed plasma levels. Among them, the highest dose was 20 mg, which is twice the therapeutic dose. We concluded that ITKL did not prolong the QT interval in healthy subjects within the therapeutic dose. Retrospectively registered: The study was registered at Chinese Clinical Trial Registry with registration number ChiCTR1800014466.