- Subjects taking the following medications may experience QT/QTc interval prolongation and are not eligible for the trial - most anti-arrhythmia drugs (incl. amiodarone), erythromycin, quinolone antibiotics, ketoconazole, Zithromax, and phenothiazine and will be denied enrollment in the study. The possible interactions of these drugs and DM-CHOC-PEN have not been established. Subjects receiving these drugs will only be eligible if they discontinue the drugs and have an acceptable ECG.