Prilosec and Nexium have the same active ingredient. You'd be better off taking one of the other twice a day than spliting it, though I suppose it really doesn't make a difference, but why would you want to take 2 different drugs? I mean, it's like saying you take Tylenol in the morning and Acetaminophen at night- they're the same. I believe Losec is Prevacid- so that makes a difference, because they are two different drugs. That might be done to prevent tolerance to one drug. I'm wondering if some of the other people here who take both are doing so because their prescription medication isn't doing enough for them, so they are supplementing with the OTC Prilosec. Pepcid is a totally different class of drugs, so I could say taking that with a PPI too.