Need math for meds advice

  1. Can anyone explain to me this math question? Okay-a physician orders diazepam (Valium) 7.5 mg IV. Diazepam is supplied in a 10 mg (2-ml) Bristojet container. How many milliliters should the nurse administer?
    I have the formula: (Desired dose [D]x Quantity [Q]
    -------------------------------
    Dose on Hand [H]

    How do you figure the math out? I am really poor in math questions and would appreciate any tips. Thanks!-Aileen:wink2:
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    About leeniebeanie_2767

    Joined: Jun '06; Posts: 31

    9 Comments

  3. by   leeniebeanie_2767
    It supposed to say desired dose [D] x Quantity [Q]
    __________________________
    Dose on Hand

    Sorry for the typo
  4. by   puggymae
    Just set it up using the formula: 7.5mg X 2mL
    ____________
    10 mg

    7.5 divided by 10 is 0.75.
    Multiply 0.75 X 2 = 1.5 mL

    Do you know how to use the formula?
  5. by   mrscurtwkids4
    Well, you have the right formula to use, so all you have to do is plug in the data that is given in the problem. So you would have 7.5 ordered dose divided by the 10 you have on hand and then multiply the answer by 2 becuase the 10 is found in 2 mL's of the med. And you should get 1.5 mL. As long as you remember the formula, you should just have to plug in the given information and do the math. I'm not sure of any other helpful hints for you. Hope this helps.
  6. by   tookewlandy
    Quote from leeniebeanie_2767
    Can anyone explain to me this math question? Okay-a physician orders diazepam (Valium) 7.5 mg IV. Diazepam is supplied in a 10 mg (2-ml) Bristojet container. How many milliliters should the nurse administer?
    I have the formula: (Desired dose [D]x Quantity [Q]
    -------------------------------
    Dose on Hand [H]

    How do you figure the math out? I am really poor in math questions and would appreciate any tips. Thanks!-Aileen:wink2:
    I would use Dimensional Analysis

    mL= 2mL X 7.5mg / 10mg = 1.5mL

    it's very easy once you get the hang of it, always find what unit you want whether it be tabs, mL,mg etc. In this case it was mL. When you know what unit you want you write it, we wanted mL so we would put mL= then the numerator of the ratio we need next must match the unit of measure that you want, thats where the 2mL came in. Then the denominator would be the 10mg contained in the 2mL. The next ratio must have a mg numerator, so you see thats where the 10mg comes in. Can you see the pattern whatever the denominator of the ratio before it is the numerator that follows must match it. since the denominator in the first ratio is 10mg then the next ratio must have a numerator of mg and it did it was 7.5 mg. Then you multiply the numerators, then multiply the denominators(in this case we did not have to) and then divide the numerator answer by the denominator answer and there is the answer.

    I am just now teaching this to myself so i explained the best way i know how, sorry if i confused you at all. What i did was went out aad bought a book that teaches me dosage calcualtion and been self studying and once you get the gist of it it becomes very easy to calculate the dosages.
  7. by   Jules A
    I would really watch doing it only by the d/hxq method because I found that to be inaccurate sometimes especially if you are doing 10 question tests and can't afford to miss one. Means and extremes has worked no fail for me once I got comfortable with it:

    7.5 mg IV. Diazepam is supplied in a 10 mg (2-ml)

    7.5mg : X = 10mg : 2ml
    7.5 X 2 = 15
    15 divided by 10 = 1.5ml (give 1.5 ml)

    As long as you are careful to have the mgs and mls in the same spot on each side of the equation it is very easy. I'm not sure how other programs work but in ours we had more students fail out because of dosage than anything else. Good luck, Jules
  8. by   tookewlandy
    Quote from Jules A
    I would really watch doing it only by the d/hxq method because I found that to be inaccurate sometimes especially if you are doing 10 question tests and can't afford to miss one. Means and extremes has worked no fail for me once I got comfortable with it:

    7.5 mg IV. Diazepam is supplied in a 10 mg (2-ml)

    7.5mg : X = 10mg : 2ml
    7.5 X 2 = 15
    15 divided by 10 = 1.5ml (give 1.5 ml)

    As long as you are careful to have the mgs and mls in the same spot on each side of the equation it is very easy. I'm not sure how other programs work but in ours we had more students fail out because of dosage than anything else. Good luck, Jules
    What is the D/hxq method???
  9. by   Jules A
    Quote from tookewlandy
    What is the D/hxq method???
    Desired over have times quanity

    its an easy way to do dosing questions but not always accurate so pretty useless except for checking imo
  10. by   supernurse65
    Quote from leeniebeanie_2767
    Can anyone explain to me this math question? Okay-a physician orders diazepam (Valium) 7.5 mg IV. Diazepam is supplied in a 10 mg (2-ml) Bristojet container. How many milliliters should the nurse administer?
    I have the formula: (Desired dose [D]x Quantity [Q]
    -------------------------------
    Dose on Hand [H]

    How do you figure the math out? I am really poor in math questions and would appreciate any tips. Thanks!-Aileen:wink2:
    i do them upside down because it makes more sense to me to put desired dose on the bottom to me maybe that would help you too
    Last edit by supernurse65 on Aug 28, '06
  11. by   LilPeanut
    Personally, I always get the stuff I have into how much I have per ml.

    a physician orders diazepam (Valium) 7.5 mg IV. Diazepam is supplied in a 10 mg (2-ml) Bristojet container.
    So first, I see in the container, there's 2 mls, with 10mg. divide that by 2, so I know I have 5mg/ml. I need to have 7.5 mg, and 7.5/5 is 1.5.

    It works for me and I've never had a problem with doing meds calc

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