FDA Approves Drugs for Angina Treatment: Rhone-Poulenc Rorer Inc. said the Food and Drug Administration has approved its diltiazem hydrochloride drug to treat chronic stable angina. Ivax Corp. said its generic version of diltiazem hydrochloride has also been given FDA approval, also for angina. Diltiazem hydrochloride is part of a group of drugs known as calcium channel blockers, which restrict the movement of calcium into the cells of heart and blood vessels. This helps the vessels relax, increasing the supply of blood and oxygen to the heart and reducing its workload. Rhone-Poulenc Rorer is the U.S. subsidiary of French pharmaceutical company Rhone-Poulenc.