Hello, Diltiazem HCl is a calcium channel blocker that does not contain the diuretic hydrochlorothiazide. It is sold under several brand names including Cardiazem LA, Dilacor, and Tiazac.Verapamil HCl also does not contain HCTZ.hen i was given a beta blocker with the initials hcl after it it had a diuretic in it and was warned to drink lots of water and stay out of the sun to prevent photosensitivity because it had a diuretic in it and the diltiazem had the same warnings in it because it has a diuretic in it.