I get the strong impression that the FDA regards ephedra and ephedrine in the same category. See:
While it is true that ephedrine is the distilled active ingredient of ma huang/ephedra (which, as you stated, is present in some cold medications) and is therefore more potent, first off the labs that manufacture OTC cold medications are carefully monitored by the government to ensure that the ingredients in the product jive with what is listed on the label - thanks to the 1994 Dietary Supplement Act, the companies that produce ephedra/ephedrine products as dietary supplements are NOT monitored by the FDA. There is one study in particular which found that the amount of active ingredients in various products can be way over the amount listed - or not present at all. Personally, that bothers me.
Another point to make is that users of cold medications containing ephedrine will generally take them for very short periods (a week or less) at a time. Ephedra/ephedrine diet 'aids' will generally instruct on their label to use the product 12 weeks (I'd be willing to bet that many users just keep using it). And the amount per pill or capsule
is different from the amount per recommended dose
as many of the diet pills state to take 2 or 3 capsules twice or even three times daily. For example, Xenadrine (judging from the posts here on 3FC, one of the most popular products currently) lists a serving size as being '2 capsules' on its Nutrition Facts label, with MaHuang standardized for 20mg of ephedrine. The directions state to take 2 capsules twice daily - so that would be 40mg of ephedrine, every day for 12 weeks (at least).
Compared with taking 30-60 mg of ephedrine for a few days to battle a cold, that's quite a difference! And note as I stated above - just because the label says there's 'x' amount of active ingredients in the product, doesn't mean there is - there could be just a trace amount or way more than the label states.
I'm not trying to start a debate here - just wanted to put in my 2 cents as usual!