Pharmacy Calculations

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shroomysoup

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  1. Pre-Pharmacy
I have a pharmacy math proficiency exam coming up. Please help! Thanks. Sorry if my work is hard to read. I couldn't format the way I wanted to.

1) A high dose treatment of osteosarcoma includes the use of methotrexate at starting dose of 12 g/m^2 as a 4-hour intravenous infusion. For a patient having a BSA of 1.7m^2 and weighing 162 lbs, calculate the dose on the basis of mg/kg/min. (Answer is 1.15 mg/kg/min)

I multiplied the 12g/m^2 and 1.72 m^2 and got 20.64 g. I don't know what to do from there.


2) Atrovent nasal spray contains 0.03% of ipratropium bromide in a 30 mL metered dose container. If the container is calibrated to deliver 345 sprays, calculate the volume of each spray, in microliters, and the medication content of each spray, in micrograms (Answer: 86.96 and 26.09 micrograms)

I don't know how to do this one! 😡


3) A starting pediatric dose of DILANTIN sodium is 6 mg/kg/day, administered in three equally divided doses. Using tablets containing 50 mg of phenytoin sodium, a pharmacist prepared a suspension such that each 1 mL, delivered from a calibrated dropper, contained a single dose for a 44 pound child. How many tablets should be used to prepare 30 mL of the suspension? (Answer is 24 tablets)

I did

6 mg x
------ = ---- with x = 120 mg
2.2 lbs 44 lbs

Then I did:

120 mg x
----------- = ---- with x = 3600 mg
1 mL 30 mL

Then I did:

3600 mg x 1 Tablet
---------- = 72 tablets (wrong of course)
50 mg


4) How many mg each of REGLAN. ATIVAN, and COMPAZINE are contained in each mL of the injection? (Answers: REGLAN = 1.13, ATIVAN = 0.0075, COMPAZINE = 0.075)

REGLAN (5 mg/mL) 30 mL
ATIVAN (2 mg/mL) 0.5 mL
Mannitol, 25% 50 mL
COMPAZINE (5 mg/mL) 2 mL
Dextrose Injection, 5% 50 mL

(For REGLAN, I did:

5 mg x
------- = ----- with x = 150 mg
1 mL 30 mL

Then I did:

150 mg x
--------- = ------- with x = 3 mg (wrong answer)
50 mL 1 mL
 
1) A high dose treatment of osteosarcoma includes the use of methotrexate at starting dose of 12 g/m^2 as a 4-hour intravenous infusion. For a patient having a BSA of 1.7m^2 and weighing 162 lbs, calculate the dose on the basis of mg/kg/min. (Answer is 1.15 mg/kg/min)

I multiplied the 12g/m^2 and 1.72 m^2 and got 20.64 g. I don't know what to do from there.
Me either, since I have no idea where the weight comes in.

2) Atrovent nasal spray contains 0.03% of ipratropium bromide in a 30 mL metered dose container. If the container is calibrated to deliver 345 sprays, calculate the volume of each spray, in microliters, and the medication content of each spray, in micrograms (Answer: 86.96 and 26.09 micrograms)
30 mls divided by 345 sprays = 0.08695562 ml
1000 microliters X 0.08695562 ml = 86.96 microliters I'll let you figure out the mg part


I don't know how to do this one! 😡


3) A starting pediatric dose of DILANTIN sodium is 6 mg/kg/day, administered in three equally divided doses. Using tablets containing 50 mg of phenytoin sodium, a pharmacist prepared a suspension such that each 1 mL, delivered from a calibrated dropper, contained a single dose for a 44 pound child. How many tablets should be used to prepare 30 mL of the suspension? (Answer is 24 tablets)

First convert the child's weight in to KG.
Then figure the total number of mg's per day.
Divide the total # of mgs by 3 doses per day to get the # of mg's per dose.
Multiply the # of mg's per dose by the number of doses (30) to get the total # of mg.
Divide the total number of mg by 50mg/tablet and you will get 24.

I did

6 mg x
------ = ---- with x = 120 mg
2.2 lbs 44 lbs

Then I did:

120 mg x
----------- = ---- with x = 3600 mg
1 mL 30 mL

Then I did:

3600 mg x 1 Tablet
---------- = 72 tablets (wrong of course)
50 mg


4) How many mg each of REGLAN. ATIVAN, and COMPAZINE are contained in each mL of the injection? (Answers: REGLAN = 1.13, ATIVAN = 0.0075, COMPAZINE = 0.075)

REGLAN (5 mg/mL) 30 mL
ATIVAN (2 mg/mL) 0.5 mL
Mannitol, 25% 50 mL
COMPAZINE (5 mg/mL) 2 mL
Dextrose Injection, 5% 50 mL

(For REGLAN, I did:

5 mg x
------- = ----- with x = 150 mg
1 mL 30 mL

Then I did:

150 mg x
--------- = ------- with x = 3 mg (wrong answer)
50 mL 1 mL[/quote]

You have to do this by the total number of ML's in the final solution:

Reglan =

5 mg X mg
------- X -------- x = 150mg
1 ml 30ml

Now for part two:

150 mg X mg
------- X --------
132.5 ml 1 ml

132.5 X = 150

x=1.13

My basic advice to you is every problem is to be solved by the ratio and proportion method. Break the problem down to it's component parts. Even if you think you can do it in your head, don't. The teachers place wrong answers that can occur when you skip a step or reverse something while doing the calculation in your head.

Just about every word problem in pharmacy math can be done by the simple 6th grade math word problem. If you are traveling in a car at 50 mph and the destination is 180 miles away, how long will it take to get there?

60 mi 180 mi
------- X --------
1 hr x hr

60 x = 180
x=3 hours
ALL PHARMACY MATH PROBLEMS WILL BE SOLVED BY THIS METHOD. YOU NEED TO FIND OUT WHAT THE DATA IS FROM THE WORD PROBLEM. YOU MAY HAVE TO MAKE MULTIPLE CALCULATIONS. BUT IF YOU LOOK IN THE PROBLEM YOU WILL SEE THEY WILL PROVIDE YOU WITH INFORMATION TO POPULATE THE EQUATION.
 
#1 is pretty straightforward:
(12*1.7*1000)/(162/2.2)/240

lots of shorthand 🙄
 
Woooo Hooooo!!!!!! I knew it would not take long!!!! You get the prize for the first calculations/kinetics question asked in the new school year. I have been waiting for this moment for months.....What a great day....👎thumbdown👎

People this is not a place to get homework questions answered. Members stop answering the questions so they will stop asking them. This is not the student doctor network homework solution forum.
 
Woooo Hooooo!!!!!! I knew it would not take long!!!! You get the prize for the first calculations/kinetics question asked in the new school year. I have been waiting for this moment for months.....What a great day....👎thumbdown👎

People this is not a place to get homework questions answered. Members stop answering the questions so they will stop asking them. This is not the student doctor network homework solution forum.

What's wrong with getting help when you need it????

I can understand not sharing board questions, but seriously, what is so bad about someome trying to understand a concept - these are just arithmetical/mathematical ones???
 
What's wrong with getting help when you need it????

I can understand not sharing board questions, but seriously, what is so bad about someome trying to understand a concept - these are just arithmetical/mathematical ones???

It's not allowed on some of the other SDN forums. I personally don't have a problem with it in the pharmacy forum as long as it doesn't get out of hand and as long as people don't take advantage. I think the community can self-police on people who are just freeloading and not really trying to understand.
 
Woooo Hooooo!!!!!! I knew it would not take long!!!! You get the prize for the first calculations/kinetics question asked in the new school year. I have been waiting for this moment for months.....What a great day....👎thumbdown👎

People this is not a place to get homework questions answered. Members stop answering the questions so they will stop asking them. This is not the student doctor network homework solution forum.

And at least they tried to work a little bit out, instead of just saying, "Do it for me" 🙄
 
What's wrong with getting help when you need it????

I can understand not sharing board questions, but seriously, what is so bad about someome trying to understand a concept - these are just arithmetical/mathematical ones???

Uhhhh...because they are not trying to understand a concept they are trying to get someone to answer the question so they can copy it and move on. Trying to understand the concept is struggling with the problem untill you figure it out. There not hard questions, people are just lazy and all of you who try to show off by answering the questions are not helping them.

Plus it is boring and I do not believe this is the place for it.
 
What's wrong with getting help when you need it????

I can understand not sharing board questions, but seriously, what is so bad about someome trying to understand a concept - these are just arithmetical/mathematical ones???

I just realized something. You typed a reply in under 5000 words! I did not think that was possible....WOW!!!!:laugh:
 
I just realized something. You typed a reply in under 5000 words! I did not think that was possible....WOW!!!!:laugh:


:laugh::laugh::laugh::laugh: see - I'm trainable! (tell Caverject!).

Also - I didn't give the answer(s)! 😀

How's the knitting (or book - you bored devil!)???
 
Woooo Hooooo!!!!!! I knew it would not take long!!!! You get the prize for the first calculations/kinetics question asked in the new school year. I have been waiting for this moment for months.....What a great day....👎thumbdown👎

People this is not a place to get homework questions answered. Members stop answering the questions so they will stop asking them. This is not the student doctor network homework solution forum.

and they already had some answers. I think they were simply looking for explanation how to get there. I'd rather see teaching/explaining than a bunch of complaining and rants about this and that.
 
First one is easy. If it is asking mg/kg/min, to find mg, you take the g and convert it to miligram by multiplying that number by 1000. To find the KG, you divide 162 lbs by 2.2 (to convert lb to kg, its x/2.2). To find the min, you take 4 hours and multiply it by 60.

The second one, you have to do some conversions. The most important missing piece of information is 0.03 percent iprat. That is weight over volume (g/ml), so you put it in a ratio form. 0.03g over 100ml equal to X over 30 ml. You find the volume in each spray (what old timer told you) for the first part, and for the microgram, you convert the gram (from the ratio equation), divided by the spray, times 1000000.


As what MountainpharmD said, I agree. These problems are basic easy problems that you can probably solve with the help of your textbook. There is almost no concept involve.
 
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