ROLESVILLE, N.C. — Filling a prescription can give consumers "sticker shock" -- especially for people who do not have insurance. Most people just buy prescription medications where it is convenient, but doing so can be costly. Five on Your Side found it pays to shop around.

For many people, prescription medication can be a matter of life or death. Michael Harris says for him, medication makes life worth living. He takes Fluoxetine, a generic form of Prozac, for depression.

"Instead of just feeling kind of blah and just getting around, I feel normal, which is good. I can get out and go paint," he said.

Harris is a self-employed painter who does not have health insurance. He was paying $73 a month for his medication but found the same medicine on the Internet for $40, including shipping.

Harris later found an even better deal at a local drugstore -- $28.50 for a month's supply. That is less than half of what he paid before.

"I was disgusted. Absolutely disgusted," he said. " I thought there would be some differences, but they would be within 5 percent or somewhere in that ballpark. Nothing this drastic."

So how different can prescription drug prices be? To find out, Five On Your Side called pharmacies at four major chains: CVS, Eckerd, Target and Wal-Mart. We got prices for popular name-brand and generic oral contraceptives, blood pressure, diabetes and allergy medications.

Prices for the blood pressure medication, Zestril, ranged from $56 to $65; a $9 difference for 30 pills. Sixty doses of the diabetes medication, Glucophage, ranged from $47 to $58; an $11 difference. The price spread for 60 doses of Allegra-D was also $11.

Price differences for generics were even more drastic. Consumers could pay as much as 50 percent more for generic birth control pills and 75 percent more for generic diabetes medication depending on where they were purchased. Generic blood pressure medication could cost almost twice as much.

"I'm sure the consumers, your viewers, will be surprised to see these differences in numbers, but it doesn't surprise me," said David Work, executive director of the

North Carolina Board of Pharmacy

. Work said many people do not realize drug prices are so different, in part, because the cost to retailers is so different.

"Pharmaceutical manufacturers will sell a product to a mail-order pharmacy at a much lower price than they will sell that same product to an independent pharmacy or even a chain pharmacy or even a hospital. It's just bizarre," he said.

Work said retailers then charge consumers whatever they think they will pay.

The retailer that most often had the highest prescription prices in Five On Your Side's phone survey was CVS. Eckerd was next, followed by Target. Prices were generally lowest at Wal-Mart.

The bottom line for consumers: It pays to shop around.

"I'd been paying that money for quite some time. I'd like to get it back, but I can't. You know it was all a fair deal. They charged a price and I paid it, but it's not going to happen again," Harris said.

In a statement, CVS explained the price differences, saying some pharmacies in giant discount stores "purposely operate at a loss" to "get you in the door" for other purchases. They added that price is only one consideration in choosing a pharmacy.

Work believes manufacturers should be required to charge the same price for the same drug to all retailers. He thinks that might help level out prices.