[NMB107]

Hi I have a question I would appreciate any help I have a dosage and calculations exam this friday and this practice question is giving me problems it goes. By the way its a reconstitution problem. Ordered: Pen G 1,000,000 Units IM q 6h
Available the label says 5,000,000 units per vial Pen G for injection USP
preparation for solution: Add 23ml, 18ml, 8ml, or 3ml diluent to provide 200,000 u, 250,000 u, 500,000 u, or 1,000,000 u per ml respectively.

The answers my school gave on the practice test is Add 3ml diluent and administer 1ml per dose or 8ml diluent and administer 2ml.

Please can anyone break this down for me.

[beth66335]

1,000,000u: 1ml :: 1,000,000: x ml
1,000,000x= 1,000,000
x=1ml

500,000u: 1ml :: 1,000,000: x ml
500,000x= 1,000,000
x=2ml

Does this help? It is Ratio and Proportion. I always use this unless it is IV drip rates then I use DA. Try to eliminate all the extra data when solving. You don't really need to worry about the diluent at first because the problem breaks it down for you, you just need to solve for you dose desired per ml.

[Daytonite]

Originally Posted by NMB107

Hi I have a question I would appreciate any help I have a dosage and calculations exam this friday and this practice question is giving me problems it goes. By the way its a reconstitution problem. Ordered: Pen G 1,000,000 Units IM q 6h
Available: the label says 5,000,000 units per vial Pen G for injection USP preparation for solution: Add 23ml, 18ml, 8ml, or 3ml diluent to provide 200,000 u, 250,000 u, 500,000 u, or 1,000,000 u per ml respectively.

The answers my school gave on the practice test is Add 3ml diluent and administer 1ml per dose or 8ml diluent and administer 2ml.
Please can anyone break this down for me.

Draw pictures for yourself if it will help. There are actually 4 different problems here. I like to use the formula dose desired divided by the dose on hand multiplied by the amount that the dose on hand comes in gives you the amount to give.


If you mix the 5,000,000 units with 23 mL of diluent you will have a solution of 200,000 units/mL (information given in the problem). Ordered: Pen G 1,000,000 Units IM q 6h. How much Pen G will you give?

1,000,000 units (dose desired)/200,000 units (dose on hand) x 1 mL (amount the dose on hand comes in) = 5 mL (amount to give)

If you mix the 5,000,000 units with 18 mL of diluent you will have a solution of 250,000 units/mL (information given in the problem). Ordered: Pen G 1,000,000 Units IM q 6h. How much Pen G will you give?

1,000,000 units (dose desired)/250,000 units (dose on hand) x 1 mL (amount the dose on hand comes in) = 4 mL (amount to give)

If you mix the 5,000,000 units with 8 mL of diluent you will have a solution of 500,000 units/mL (information given in the problem). Ordered: Pen G 1,000,000 Units IM q 6h. How much Pen G will you give?

1,000,000 units (dose desired)/500,000 units (dose on hand) x 1 mL (amount the dose on hand comes in) = 2 mL (amount to give)

If you mix the 5,000,000 units with 3 mL of diluent you will have a solution of 1,000,000 units/mL (information given in the problem). Ordered: Pen G 1,000,000 Units IM q 6h. How much Pen G will you give?

1,000,000 units (dose desired)/1,000,000 units (dose on hand) x 1 mL (amount the dose on hand comes in) = 1 mL (amount to give)

[nrsgnerd]

Originally Posted by NMB107

Hi I have a question I would appreciate any help I have a dosage and calculations exam this friday and this practice question is giving me problems it goes. By the way its a reconstitution problem. Ordered: Pen G 1,000,000 Units IM q 6h
Available the label says 5,000,000 units per vial Pen G for injection USP
preparation for solution: Add 23ml, 18ml, 8ml, or 3ml diluent to provide 200,000 u, 250,000 u, 500,000 u, or 1,000,000 u per ml respectively.

The answers my school gave on the practice test is Add 3ml diluent and administer 1ml per dose or 8ml diluent and administer 2ml.

Please can anyone break this down for me.

The more diluent you add, the less concentrated the dose will be meaning adding 3ml gives the solution the strength of 1,000,00u/mL vs. adding 23 mL gives the solution the strength of 200,000 u/mL. Since you need to give 1,000,000 units, you will add 3 mL to give the dose you draw up into the syringe 1,000,000 u/mL .

NOTE: always add the amount of diluent that is closest to the dose that has been ordered to give. For instance, if the doc ordered 100,000 u you would add 23 mL making the strength 200,000u/ml and you would draw 0.5 mL into the syringe. By doing so you have 100,000 u of PenG to give. Hope this helps. Another example would be the doc has ordered 225,000 u which seems like theres not a right answer since this fall right between 200,000 and 250,000 but, always choose the strength that will require the least amount of mL's to draw up which in this case would be the 250,000. PenG hurts going in IM so its a matter of pt. comfort.

[NMB107]

Thank you all for your help its truly appreciated. God bless You guys are the best....

[studymom39]

There are different methods for math, pick the one you feel you're most competent on and stick with it from start to finish. I, for example, prefer the dimensional analysis way (like what you learned in chemistry).

I have a very strong opinion about the void that our program had in reviewing math. The advisors stated, "math is an assumption if you passed chemistry" but for nontraditional students, I was not fresh out of high school and didn't remember the metric system. Furthermore, I researched the math class available to me and took 3, one was specific to the health field, and it barely touched the metric system until the end. It went over very basic stuff on decimals and stuff which I didn't need.

I got through nursing school but one teacher, in particular, was on a warpath for bad evaluations from students and had multiple methods of rounding that has never been pinned down to date, and she actually failed a girl one quarter off of it. Others were kicked out class but the Dean stepped in. When the dust settled, the teacher was in the hotseat because people had written proof to show the Dean that she gave different rounding rules that were inconsistent. The next year, she didn't dare fail a student or she'd have been fired. If there was confusion, she "remediated".

The math should be taught in each quarter. It wouldn't take much time at all. Also, get into small groups to teach each other.

[Anubis]

It's nice to know I'm not the only one out there who has math issues!

[athina2004]

I have the same problem.All this was very helpful.Thanks a lot

[ThinkRNin2009]

Total mental block on this math question....If someone can help me understand I would greatly appreciate it.

Dicloxcillin 1oomg po q6h is ordered for a child weighing 35kg. The recommended dosage is 12.5mg/kg/day for children weighing less than 40kg in divided doses q6h.

What is the recommended dose for this child?
my answer is 437.5mg per day

Is the ordered dose appropriate and safe?
my answer is "yes the ordered dose is safe but not appropriate it's too low of a dosage."

The answer key has the ordered ordered dose is safe and appropriate because the 10% rule is applied, but I still don't understand.

Ugh!!! totally easy question that I can't understand

Please help.

Thanks

[Daytonite]

Originally Posted by ThinkRNin2009

Total mental block on this math question....If someone can help me understand I would greatly appreciate it.

Dicloxcillin 1oomg po q6h is ordered for a child weighing 35kg. The recommended dosage is 12.5mg/kg/day for children weighing less than 40kg in divided doses q6h.

What is the recommended dose for this child?
my answer is 437.5mg per day

Is the ordered dose appropriate and safe?
my answer is "yes the ordered dose is safe but not appropriate it's too low of a dosage."

The answer key has the ordered ordered dose is safe and appropriate because the 10% rule is applied, but I still don't understand.

Ugh!!! totally easy question that I can't understand

Please help.

Thanks

12.5mg/kg/day x 35kg = 437.5 mg/day = 109.375 mg/four divided doses, the recommended dose for a 37.5kg child. A 100 mg dose would be appropriate and safe.

Check your textbook for the 10% leeway you can have in rounding off and giving the actual dosage. Giving 109 mg is not practical in actual practice, but 100 mg is.
http://www.drugs.com/pro/dicloxacillin.html - see the section on how it is supplied.