1. 0 out of 1 members found this post helpful. Good post? |

## HELP_ calculation

1)1 tablespoonful of thioridazine solution ( 100mg/cc) is diluted with water up to 1 quart, what is the % of drug in the final solution?

a)1.25%
b)0.005%
c)0.156%
d)2.75%

2)The recommended therapeutic dose for Levaquin I.V is 7mg/kg/day. The drug has elimination half life of 12hrs. Volume of distribution is 1.2l/kg. What would be the plasma concentration of the drug.? Pt wt 170lbs. What would be the initial plasma concentration of drug in mg/ml?

a)10.11 mcg/ml
b)23.12 mcg/ml
c)5.833 mcg/ml
d)33.23 mcg/ml

3)The recommended plasma concentration of cipro is 20 mcg/ml. Elimination half life 6hrs. volume distribution 0.5 l/kg. pt weight 155lbs. what would be the rate of infusion in mg/min/

a) 2.25 mg/min
b)5.60 mg/min
c)1.35mg/min
d)1.1mg/min

Please solve these qs and explain how u solved it.
Thanks.

2. Good post? |
1)1 quart is 960 cc:1 table spoon is 15 ml.
put the values in you will get C

3. Good post? |

## thank you!!

Thank you. I got it.

!5ml----1cc=100mg,Hence, 1.5gm/960*100=0.156%I was calculating as 1 teaspoon.I should be careful.

4. Good post? |
Hi
the answer for 3rd question is
Rate of infusion=CssxCL
Cl=Vd x Ke
=0.5l/kg, for 155lbs it is 35.23litres,Ke=0.693/t1/2
Ke=0.693/6=0.1155
Cl=35.23x0.1155=4.068litres/hour

we need to calculate dose for doing Css. Vd=Dose/Cp
Vd=35.23=dose/20mcg/ml 20mcg=0.02mg/ml
since Vd is in litres, 0.02x1000=20 mg in litres

Dose=35.23x20=704.6mg

Css=Dose/Vd= 704.6/35.23=20mg/litres

Rate of infusion-=CssxCl=20x4.068litres/hour=81.36mg/hour
as the answer inminutes, you divide by 60 to get 1.35mg/min

5. Good post? |
Hi
The answer for 2nd question is

Vd=1.2l/kg, so 170lbs is 77.27kg
so 1.2 x 77.27=92.72litres or 92720 ml

Vd=Dose/Cp
Cp=plasma concentration Dose/Vd
=dose=7mg/kgx77.27kg=540.89mg is 0.54089mcg
Cp=0.54089/92720
=5.833mcg/ml

6. Good post? |
Thanks Sunitha siva for the explanation of problems. I understood.

7. Good post? |

1)5% w/v solution of phenol is diluted by adding 200ml to 4 liters water. What is the strength of the final product?

2)The concentration of codeine in cough syrup is 65mg/30ml. How many ml of diluent should be added to 120 ml of this syrup to obtain a pediatric dos of 1mg/ml?

3)What is the new strength of a solution prepared by diluting with water , 1 pint of a 1:750 strength solution to i gallon?

A)) A patient has bradyarrythmia. Choose the drug which will not worsen pt condition?
a)verapamil
b)sotalol
c)digoxin
d)amlodipine
e)Diltiazem.

8. Good post? |
1). 5% => 5g -- 100 ml
? -- 200 ml => we have 10 g in 200 ml, which will be diluted to 4litters
10g in 4000 ml
? g in 100 ml => so the strength of the final solution is 1000/4000= 0.25 => 0.25 %

2). 65mg in 30 ml => we have 260 mg in 120 ml, to obtain a concentration of 1mg/ml we need 260 ml
so we need 140 ml of diluent to add to 120 ml of the syrup.

3). 1 pint of 1/750 will be diluted to 1 gallon ( 8 pints )
1/750/8 = 1/6000

4). D​, The only drug in the list that does not lower HR is amlodipine

9. Good post? |
1)5% solution is diluted to 200ml so 200ml will have 5g...please explain? All the answers are correct.

10. Good post? |
5% means 5g in 100 ml, so in 200ml you have 10g. When you dilute it to 4000ml, it means that you have 10g in 4000ml. To get the % strength you have to find how many g are in 100ml
10 g -- 4000ml
Xg -- 100ml. => X= 10x100/4000=0.25
X= 0.25%