Wal-Mart Stores will begin selling eight additional generic drugs for $4 per 30-day prescription and several family-planning drugs for $9. The added medications include treatments for glaucoma, attention deficit disorder, attention deficit hyperactivity disorder, fungal infections and acne. In addition, Wal-Mart will offer generic versions of the birth control drugs Ortho Cyclen and Ortho Tri-Cyclen and a fertility drug for $9 per 30-day supply.

The discount drug program, which started in September 2006, now will cover 361 prescriptions representing different formulations of 157 generic drugs. The new additions add about 24 prescriptions to the program.

Other retail chains, including Kmart, Publix and Target, have advertised similar programs.