Med Calculations Flashcards
These tablets are not meant to be crushed and and prevent gastric mucosa irritation.
Enteric Coated tablets
Amounts less than ____ should be measured in a syringe, rather than a medicine cup.
10mL
Order: Levothyroxine 75mcg po oc
Supply: Levothyroxine 0.15mg per tab
How many tabs should you give?
convert mg -> mcg = 150mcg
D/SxQ=
75/150x1
=0.5 tabs should be given.
Levothyroxine 0.05mg po oc
Supply: Levothyroxine 25mcg tab
How many tabs should the patient receive?
Convert - 0.05mg to mcg = 50mcg D/SxQ= 50/25x1= 2 2 tabs should be given.
Order: Avapro 0.25g po q4h
Supply: Avapro 50mg tabs
How many tabs should be given?
Convert - 0.25g=25mg
D/SxQ=
25/50x1= 0.5
0.5 tabs should be given.
Order: Pregabalin 150mg po BID
Supply: Pregabalin 50mg capsules
How many capsules should they receive?
D/SxQ=
150/50x1 = 3
3 capsules should be given
Meperidine 75mg po q4h prn
Supply: Meperidine 50mg/5mL
How much suspension should they receive?
D/SxQ=
75mg/50mgx5mL
=7.5mL should be given
Amoxicilin 100mg po qid
Supply: Amox 125mg/5ml
Hw much should they receive?
D/SxQ=
100/125x5=
4mL should be given
Digoxin Elixir 250mcg
Supply: Digoxin elixir 0.10mg/mL
CONVERT - 250mcg=0.25mg
D/SxQ=
- 25/0.10x1mL
- 5 mL should be given
Lactulose 10g po daily
Supply: Lactulose 667mg/1mL
How much should they receive?
CONVERT - 10g = 10,000mg
D/SxQ=
10000/667x1
=14.99 (15mL) per day
This injection site is typically used for children under 12 months of age.
Vastus Lateralis Muscle.
What is the typical maximum amount that can be injected into the deltoid muscle?
1 mL
Clindamycin 150mg IM q12H
Supply: Clindamycin 300mg/2mL
How much should they receive?
D/SxQ=
150mg/300mgX2mL
=1mL should be given
Demerol 75mg IM q4h
Supply: Demerol 50mg/mL
How much demerol should be given each dose, and how much is given each day?
D/SxQ=
75mg/50mgX1mL
=1.5mL is given each dose
1.5mL x 6 (q4h) = 9mL is given each day
Heparin NA 1500 Units SC q12h
Supply: Heparin NA 5000 Units/0.5ml
How much should the patient receive?
D/SxQ=
1500U/5000Ux0.5mL
=0.15mL should be given
Which type of insulin do you draw up first in a syringe, Cloudy or Clear?
CLEAR, this is because you do NOT want to introduce cloudy insulin to a clear insulin vial
Which insulins are clear? Rapid and short acting insulins, or intermediate acting insulin?
Rapid / Short acting insulin is clear, intermediate insulin is cloudy.
Convert 10lb 12 oz into Kilograms.
12oz/16oz=0.75lbs
1kg =2.2lbs
_kg=10.75lbs
10.75lbs/2.2lbs/kg = 4.88 (4.9) kg
Convert 18 lbs 4oz into kilograms.
4oz/16oz=0.25lbs
1kg=2.2lbs
_kg=18.25lbs
18.25lbs/2.2lbs/kg= 8.29 (8.3) kg
Hydroxyzine HCl 20mg IM q4h for a child that weighs 44lbs.
[Safe dosage is 0.5mg - 1mg/kg/dose every 4 hours prn].
Calculate, and identify if this is a safe dosage for this child.
Convert lbs into kg - 44lbs/2.2lbs/kg= 20kg
Minimum dose= 0.5mgX20kg = 10mg/dose q4h
Max dose = 1mgX20kg = 20mg/dose q4h
This is a safe dosage for the child.
Amoxicillin 200mg PO q8h for a child weighing 22lbs.
Safe range for Amoxicillin is 20-40 mg/kg/day if divided every 8 hours.
Calculate, and identify if this is a safe dosage for the child.
Convert weight into kg.
22/2.2lbs/kg= 10kg
Minimum dose = 20mg/kg/dayX10kg= 200mg/day
200mg/3 (q8h) = 66.7mg/q8h dose
Maximum dose = 40mg/kg/dayX10kg= 400mg/day
400mg/3 = 133.3mg/q8h dose
range is 66.7mg - 133.3mg every 8 hours for this child, making the dosage of 200mg UNSAFE.
Tobramycin 35mg IV q8h for a child weighing 14kg.
Safe range for drug is 6-7.5mg/kg/day
Calculate and identify if the dose is safe for this child.
Weight conversion not needed.
Minimum dose = 6mg/kg/dayX14kg = 84mg/day
84mg/3 doses (q8h) = 28mg q8h
Max dose = 7.5mg/kg/dayX14kg = 105mg/day
105mg/3 = 35mg q8h
This is a safe dose for this child.
How is drops per millilitres shown in a formula?
gtt/mL
What does the abbreviation D5W mean on an IV bag?
Dextrose 5% in water
What does the abbreviation D5LR mean on an IV bag?
Dextrose 5% in Lactated Ringer’s
What does the order D5NS 1000mL IV q4h mean?
Provide 1000mL Dextrose 5% in Normal Saline IV every 4 hours
0.45% Saline is an example of an: A/ Isotonic solution B/ Hypotonic Solution C/ Hypertonic Solution D/ Equilibric Solution
B/ Hypotonic solution
Used to dilute excess serum levels of electrolytes (Hyperglycaemia)
0.9% saline is an example of an: A/ Isotonic solution B/ Hypotonic Solution C/ Hypertonic Solution D/ Equilibric Solution
A/ Isotonic solution
Used to expand volume and maintain normal tonicity.
D5% is an example of an: A/ Isotonic solution B/ Hypotonic Solution C/ Hypertonic Solution D/ Equilibric Solution
C/ Hypertonic solution
Used to correct electrolyte imbalances by adding more solutes than solvent. Example: diarrhea
Calculate how much D5% is in a 500mL bag, if there is 5g of dextrose in a 100mL bag
5g/100mL = Xg/500mL
100X/2500=25g of D5 is in a 500mL bag
How much NS 0.9% is in a 1000mL bag, if there is 0.9g in a 100mL bag.
0.9g/100mL = Xg/1000mL
900/100X= 9g of NS is in a 1000mL bag
A doctor orders 500mL of NS to be infused over 4 hours. What is the amount of NS in mL infused over 1 hour?
500mL/4hours= 125mL/hour
A doctor orders 50mL of ampicillin to be infused over 30 minutes. What is the mL/h?
50mL/30minutesX60mins/h = 100mL/hour
The Doctor orders 250mL D5W over 2h. What is the infusion rate in mL/h?
250mL/2hours= 125mL/h
The Doctor orders 500mL of D5W over 45 minutes. What is the infusion rate in mL/h?
500mL/45minX60min= 666.66mL/h
A random Doctor orders 3200mL of NS over 25minutes. What is the infusion rate in mL/h?
3200mL/25minX60min= 7680mL/h
Calculate the flow rate:
D5W 1000mL infused over 10 hours
1000mL/10hours = 100mL/h
Calculate flow rate
NS 2500mL in 20 hours
2500mL/20hours = 125mL/h
Calculate the flow rate:
D5W 500mL in 6.5 hours
500mL/6.5hours = 77mL/h
Calculate the flow rate:
NS 0.4% 500mL infused over 25 minutes.
500mL/25minX60min = 1200mL/h
Calculate the flow rate:
LR 100mL infused over 45 minutes.
100mL/45minX60min = 133.33mL/h
In the formula, V/TxC=R
explain what each letter represents
V= volume per hour (125mL/h) T= Time required to infuse V (25 minutes) C= Calibration of tubing/Drop factor (15 gtt/mL) R= Rate of flow in gtt/min (21 gtt/min)
Order: D5W NS IV at 50mL/h. Drop factor is 60gtt/mL
What is the drip rate per minute for the IV?
V/TxC=R
50mL / 60minutes X 60gtt/mL = 50gtt/min
Order: NS IV 3000mL/24h. Drop factor is 15gtt/miL
Calculate the drip rate/min
Get 3000mL/24 into mL/1h: 3000/24 = 125mL/h
V/TxC=R
125mL / 60min X 15gtt/mL = 31 gtt/min
Order: NS IV 2000mL/12h. Drop factor is 15gtt/mL
Calculate the drip rate/min
Convert 2000mL/12h into mL/1h: 2000mL/12h = 167mL/h
V/TxC=R
167mL / 60 min X 15gtt/mL = 41.75 (42) gtt/min
Order: LR 500mL/4h. Drop factor is 10gtt/mL
Calculate the drip rate/min
Convert 500mL/4h into mL/1h: 500/4 = 125mL/h
V/TxC=R
125mL / 60 min X 10gtt/mL = 21 gtt/min
Order: NS 2000mL/12h IV. Drop factor is 15gtt/mL
Calculate the drip rate/min
Convert 1000mL/12h into mL/1h: 1000/12 = 83mL/h
V/TxC=R
83mL / 60 min X 15gtt/mL = 21 gtt/min
Order: Cefazolin 0.5g in 100mL D5W IV infused over 15min. Drop factor is 10 gtt/mL
Calculate the flow rate in gtt/min
V/TxC=R
100mL / 15min X 10gtt/mL = 67gtt/min
Order: Oxacillin NA 500mg in 125mL D5W IV infused over 45 minutes. Drop factor is 15gtt/mL
Calculate flow rate in mL/h, and then the flow rate in gtt/min
125mL/45minX60min = 167mL/h
V/TxC=R
167mL / 60min X 15gtt/mL = 42gtt/min
Order: Amoxicillin 275mg in 500mL NS IV infused over 2 hours. Drop factor is 60gtt/mL
Calculate flow in mL/h, and then the flow rate in gtt/min
500mL/2hours = 250ml/h
V/TxC=R
250mL / 60 min X 60gtt/mL = 250gtt/min
Order: Cialis 500mg po q2h
Supply: Cialis 125mg
How many pills can you give? How many pills would be given each day?
D/SxQ = 500/125x1 = 4 pills can be given every 2 hours
4 pills x 12 = 48 pills per day… mega Boner.
Order: NS 2.5L IV to infuse at 175mL/h. Drop factor is 10gtt/mL
What is the flow rate in gtt/min?
Convert L to mL - 2.5x1000= 2500mL
V/TxC=R
2500mL / 60 min X 10gtt/mL = 417gtt/min
Order: Humulin N 55units and NovoRapid 15units.
Which insulin would you draw from first, and how many mL would you have after drawing up each type of insulin?
Draw up NovoRapid first because it is a rapid-acting insulin and is clear, then draw up the Humulin N with is a cloudy-intermediate insulin.
15+55= 70units
100units = 1mL so 70Units = 0.7mL
Order: Amoxiclav 300mg PO q8h for a child weighing 39lbs.
Recommended dosage is 20-40mg/kg/day
Is this order safe? calculate the min and max for this medication.
Convert lbs to kg - 39lbs/2.2 = 18kg (17.7)
Min dose = 20mg/kg/dayX18kg = 360mg/day
360mg / 3 (q8h) = 120mg per q8h dose
Max dose = 40mg/kg/dayX18kg = 720mg/day
720mg / 3 = 240mg per q8h dose
Therefore, 300mg q8h is too high and unsafe for the child
Order: Acetaminophen 200mg PO q12h for a child weighing 53 lbs.
Recommended dosage is 10-15mg/kg/day
Is this order safe? calculate the min and max for this med
Convert lbs to kg - 53/2.2 = 24kg
Min dose = 10mg/kg/dayX24kg = 240mg/day
240mg/day / 2 (q12h) = 120mg q12h
Max dose = 15mg/kg/dayX24kg = 360mg/day
360mg/day / 2 (q12h) = 180mg q12h
200mg q12h is an unsafe dose for this child as is it too high.
