mg in a grain

[kgh31386, BSN, MSN, RN]

Which one are we using? 65 or 60mg. On Hurst they used both...kinda confusing. The answer they got used 60mg. But then in the rationale, it said 1gr=65mg??

[cmmny]

60 mg = 1 gr

[elkpark]

It's v. confusing and frustrating, because, depending on what source you use, gr i can equal 60 mg, 64 mg, or 65 mg.

I remember being v. frustrated about this in nursing school and asking my father (an older MD who trained 'way back when the apothecary system was in standard use) how this could possibly be (they can't all equal gr i!!! ), and, in any given situation/calculation, how do you decide which one to use????? His wise response? "The one that makes the math work out easiest" -- that is, the one that doesn't have you supposedly drawing up or measuring out some bizarre fraction of an ml as an answer. (I'm sure that's not the rationale the NCLEX would use, but it sure works in real life. :))

[kgh31386, BSN, MSN, RN]

I figured it would be 65. Especially with a 5 grain aspirin is 325mg...equals out to 65. And 1 gram is 15.4 grains...that equals out to 65mg as well.

[Murse901, MSN, RN]

It can be 60 or 65. I haven't heard 64, but I don't doubt it. Apothecary isn't a very accurate system, so it's a little clunky converting to metric. But yes, 60 and 65 is correct. It just depends on what med you're converting. As the other poster said, the right answer is whichever one comes out to make the most sense in the math work.

[kgh31386, BSN, MSN, RN]

Well Nclex...will just give me a blank. But yeah I guess which ever comes out to the better number. lol too bad I cant put for example . 55, 64 and show them both answers