Almost 4 billion prescriptions were filled last year, and as baby boomers age, the demand is bound to rise, along with the workload from Medicare Part D. But as in years past, there's a shortage of pharmacists. There are an estimated 3,500 openings for pharmacist jobs in 44 states. Although 22 new schools of pharmacy have opened in the past few years, it takes six years of education and training to become a pharmacist.

"The cavalry is coming," says Lucin da Maine, executive vice president and CEO of the American Association of Colleges of Pharmacy. Until it arrives, the industry is developing certification programs to train pharmacy technicians to ease the burden.

Service might improve in all stores if e-prescribing ever takes off. A small fraction of doctors are writing prescriptions sent electronically to the drugstore's computer system. The procedure avoids a problem that can lead to serious mistakes: deciphering a doctor's handwriting. Major pharmacy chains were to launch a campaign in April to educate the public about e-prescribing.

More drugstores are also relying on robotic machines to dispense frequently prescribed medications automatically. They do everything but seal the bottle, which is done only after the pharmacist makes sure all is correct.