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OTTUMWA, IOWA -- Companies manufacturing caffeinated alcoholic beverages are back in the hot seat.

The Food and Drug Administration issued warning letters stating that the caffeine in the drinks is unsafe.

Some of the energy drinks contain up to 12% alcohol, whereas a can of beer contains about 4%.

The drinks can mask the effects of the alcohol and caffeine and can cause a person to drink far more than they should.

Dr. Andrew Porter of the Davis County Hospital said the caffeine in the drinks can prevent you from feeling the negative effects of the alcohol.

"Having a larger volume of alcohol can get you drunk faster," Porter said. "With the mixture of caffeine, you don't feel nearly as drunk as you would if the caffeine wasn't there."

The drinks have been pulled from store shelves in Ottumwa, but are still available at some stores in Kirksville.

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