Diltiazem HCl drug information: uses, indications, side effects, dosage. Compare prices for generic diltiazem hcl substitutes: Diltiazem-Xl, Diltiazemhydrochloride, Diltiazemhydrochloride retard Sanofi-Aventis.Diltiazem HCl hydrochloride is a white to off-white crystalline powder with a bitter...