Yesterday, regional drug store chain Duane Reade (NYSE:DRD) plunged 20% after reporting that third-quarter sales fell short, and that earnings would come between $0.08 and $0.09 per share, rather than the $0.15 to $0.20 expected.

Duane Reade operates 239 stores, all in the New York Metropolitan area. So while same-store drug sales grew 8.6%, the company cited weaker-than-expected prescription drug sales and the August blackout.

The bigger players have no such issues. CVS (NYSE:CVS), for one, continues to deliver solid growth. The nation's second-largest pharmacy chain said that September sales increased 8.8% to $2.49 billion, and that sales for the just-ended third quarter increased 8.5% to $6.38 billion. Same-store increased 6.4%, driven by an 8.5% increase in pharmacy same-store sales. Pharmacy sales accounted for 69.4% of the company's sales during the quarter.

CVS also saw fit to report that it expects to earn $0.46 per share in the coming quarter vs. Wall Street expectations of $0.43 per share. EPS for the full year is now expected to climb from $1.75 last year to between $1.95 and $2.00 per share.

Smaller rival Rite Aid (NYSE:RAD) hit a new 52-week high today, as it also reported strong September same-store sales growth of 6%. Pharmacy sales were up 6.5% and front-end sales grew 5%. Drug sales accounted for 64.4% of Rite Aid's sales for the month.

As a result of the strong sales, CVS shares are up 4.7% to $33.64 midday, while Rite Aid is up nearly 4% to $5.82.

Jeff Hwang appreciates your feedback at JHwang@fool.com.