N-Desmethyl-N-acetyl Diltiazem-d4 is the isotope labelled analog of N-Desmethyl-N-acetyl Diltiazem (D290675); a metabolite of Diltiazem (D460620, HCl) which is a calcium channel blocker with vasodilating activity. Also anti-anginal, anti-hypertensive, and anti-arrhythmic (class IV).