Dosage Calculation - Mass for Mass Questions

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Mass for Mass Questions
Given an amount of mass per tablet, how many tablets do you require?
 
Formula:  

$$\boxed{\frac{\mathbf{Ordered}}{\mathbf{Have}}=\mathbf{Y(Tablets\; required)}}$$

Example: Metroprolol (Lopressor), 25 mg PO, is ordered. Metropolol is available as 50 mg tablets. How many tablets would the nurse administer?

$$\frac{\mathbf{Ordered}}{\mathbf{Have}}=\mathbf{Y(Tablets\; required)}$$

$$\frac{\mathbf{25\; mg}}{\mathbf{50\; mg}}=\boxed{\frac{\mathbf{1}}{\mathbf{2}}\mathbf{tablets}}$$

Alternatively, 50 mg = 1 tablet
Therefore 25 mg = 1/50 x 25 = 0.5 tablets

Example: Potassium Chloride is available as 10 mg per tablet. Potassium Chloride (K-Dur), 40 mg is ordered. How many tablets would the nurse administer?

$$\frac{\mathbf{Ordered}}{\mathbf{Have}}=\mathbf{Y(Tablets\; required)}$$

$$\frac{\mathbf{40\; mg}}{\mathbf{10\; mg}}=\boxed{\mathbf{4\; tablets}}$$

Alternatively, 10 mg = 1 tablet
Therefore 40 mg = 1/10 x 40 = 4 tablets

Example: (From Ngee Ann Polytechnics Dosage Calculation Worksheet)
ORDER: Drug C 0.35 mg P.O.
AVAILABLE: Drug C tabs 0.7 mg

$$\mathbf{\text{GIVE:}}\underline{}\mathbf{\text{Tab(s)}}$$

$$\frac{\mathbf{Ordered}}{\mathbf{Have}}=\mathbf{Y(Tablets\; required)}$$

$$\frac{\mathbf{0.35\; mg}}{\mathbf{0.7\; mg}}=\boxed{\frac{\mathbf{1}}{\mathbf{2}}\mathbf{tablets}}$$

Alternatively, 0.7 mg = 1 tablet
Therefore 0.35 mg = 1/0.7 x 0.35 = 0.5 tablets

Continue (Dosage Calculation - Mass for Mass Questions - (2))

Reference

[1] Advanced Formatting, Ry’s MathML Tutorial, http://rypress.com/tutorials/mathml/advanced-formatting.
[2] MathML, Presentation MathML, https://en.wikipedia.org/wiki/MathML.
[3] MathJax in Blogger (II), Posted on Tuesday, 12 July 2011, http://irrep.blogspot.sg/2011/07/mathjax-in-blogger-ii.html
[4] MathJax, http://docs.mathjax.org/en/latest/start.html

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