For consumers who pay for prescription drugs out their own pockets, a new price study by Yonkers-based Consumer Reports finds it pays to shop around.

The consumer publication’s research showed that not only that prices vary from store to store for the same, but the differences can be dramatic — even within the same chain, depending on location.

Consumer Reports placed calls to 163 pharmacies nationwide to gauge price differences among four prescription drugs, three name brand medicines and one generic. For a three-month supply of pills for the urinary incontinence drug Detrol, for example, the price ranged from $365 to $551.

The magazine also found significant price disparities for the two other name-brand drugs it studied: for Plavix (which prevents blood clots), the spread was $382-$541, and for Levoxyl (for treating hypothyroidism), prices ran from $29 to $85. And for the generic alendronate (for osteoporosis), the price range was $124 to $306.

The magazine’s small scale market-basket study showed Costco was the cheapest for the four drugs CR sought quotes for, followed by AARP.com and Wal-Mart. Walgreens and Rite-Aid were among the priciest for the four drugs.

Besides calling different stores and comparison shopping, other cost-saving tips include:

• Don’t rule out independents: Though they’re not the cheapest overall, many mom-and-pop pharmacies are highly competitive and offer top notch service.

• Talk to your employer: Benefits administrators can provide details about pharmacy benefit managers, also known as PBMs.

• Buy generics: They can cost 20 to 50 percent less than their brand name equivalents.

• See if there’s a discount program: Some stores have programs for those 50 and older; other programs are open to anyone without insurance.

The full report is available for free now at www.ConsumerReportsHealth.org, or in the June issue of Consumer Reports magazine available on newsstands tomorrow.

Two consumer-advocacy organizations are criticizing a U.S. Food and Drug Administration investigation into a generic version of a popular, once-daily dose antidepressant, calling the regulatory agency’s review “inadequate.”

White Plains-based ConsumerLab.com and The People’s Pharmacy, of Durham, N.C., faulted a affirmative determination by the FDA that a generic version of Wellbutrin XL 300, manufactured by Impax Laboratories and distributed by Teva Pharmaceuticals,  because the findings were based on information from a lower dose of the drug.

In reporting its findings this week, the FDA said the generic version, marketed as Budeprion XL 300 milligrams, was “safe and effective.” The agency also said the generic version was equivalent, and therefore interchangeable with, Wellbutrin XL 300.

Calling the FDA’s findings disappointing, ConsumerLab.com and The People’s Lab said there was no evidence that the FDA evaluated the generic drug fully.

“For the FDA to say that it has reviewed the safety and efficacy of this product is not correct,” said Dr. Tod Cooperman, president of ConsumerLab.com.

“The FDA is misleading the public by publishing a positive review which actually provides no data for the 300 milligram product – the strength about which people are complaining,” said Joe Graedon of The People’s Pharmacy (www.peoplespharmacy.com).

The agency undertook its investigation after receiving complaints that patients taking the branded product experienced a loss of effectiveness when switched to the generic pill. Further, patients reported new onset or worsening of side effects.

Emisphere Technologies Inc. reported today that studies involving dogs have provided additional evidence that a technology the company is developing enhances absorption of oral vitamin B12 supplements.

The results confirm an earlier report of effectiveness in studies conducted in rats using Emisphere’s Eligen technology, which reportedly improves absorption of orally administered drugs.

About 40 million Americans undergo annual B12 injections to treat a variety of serious medical conditions. An addition 5 million people yearly consume more than 600 million B12 tablets in various strengths as nutritional supplements, Emisphere said.