introduction to medication calculations

Introduction to Introduction to Medication Medication

Calculations for Calculations for Nursing StudentsNursing Students

Please Click Slide to Proceed

ObjectivesObjectives

► Gain an understanding of the formulas used to calculate correct medication for administration.

► Show examples of medication formulas and calculations.

► Practice questions throughout the presentation with a test at the end.


Test Your Current KnowledgeTest Your Current Knowledge

1. A patient is ordered an injection of 80mg of Pethidine. Each stock ampoule 100mg per 1ml. How much will you draw up?

2. A patient is prescribed 3g of Sulphadiazine, the stock contains 600mg/5ml. How much Sulphadiazine should be given to the patient?

3. A patient is prescribed 1L of a Saline solution. The rate is set at 100ml/hr. How long will the infusion take?

4. How many 300mg tablets are required for a prescribed dose of 450mg?

5. A doctor orders Penicillin via Potassium oral suspension 56mg/kg/day in four doses per day for a child who weighs 25kg. The suspension available is 125mg/5ml. What volume should be administered at each dose?

Please Click Slide to Proceed when ready

AnswersAnswers

1.1. .8ml.8ml2.2. 25ml25ml3.3. 10 hours10 hours4.4. 1.5 Tablets1.5 Tablets5.5. 350mg350mg


Medication Formulas – Tablets Medication Formulas – Tablets

Strength RequiredStrength Required

Stock StrengthStock Strength= Number Of

Tablets

MEANS DIVIDE THE TOP NUMBER BY THE BOTTOMPlease Click Slide to

Proceed


Medication Example:Medication Example:

750mg750mg CIPROFLOXACIN IS ORDERED ON HAND ARE CIPROFLOXACIN IS ORDERED ON HAND ARE 500mg500mg TABLETS. TABLETS. HOW MANY TABLETS SHOULD BE HOW MANY TABLETS SHOULD BE GIVEN?GIVEN?

Strength RequiredStrength Required Stock StrengthStock Strength750mg750mg500mg500mg

= Number Of Tablets

= 1.5 TABLETS



Medication ExampleMedication Example::

HOW MANY HOW MANY 20mg20mg TABLETS OF CODEINE ARE REQUIRED TABLETS OF CODEINE ARE REQUIRED FOR A DOSE OF FOR A DOSE OF 0.05g0.05g??


Stock StrengthStock Strength

Requires ConversionRequires Conversion

g to mg – 0.05g x 1000 = 0.05 x 1000 = 50mgg to mg – 0.05g x 1000 = 0.05 x 1000 = 50mg

50mg50mg

20mg20mg

=Number Of Tablets

= 2.5 TABLETSPlease Click Slide to

Proceed

Medication Formulas – Volume / Medication Formulas – Volume / InjectionInjection


Stock StrengthStock Strength = Volume Required

X Volume

Volume in the AmpoulePlease Click Slide to

Proceed


Volume Medication Example:

CALCULATE THE VOLUMECALCULATE THE VOLUME TO BE DRAWN UP IF A PATIENT TO BE DRAWN UP IF A PATIENT REQUIRES REQUIRES 1 mg1 mg OF BUMETANIDE, AND EACH STOCK OF BUMETANIDE, AND EACH STOCK AMPOULE CONTAINS AMPOULE CONTAINS 2mg/4ml2mg/4ml

Volume Formula CalculationVolume Formula Calculation



1mg1mg 2mg2mg

= Volume To Be Administered

= 2 ml

X Volume

X 4ml



Volume Medication Example:Volume Medication Example:

AN INFANT REQUIRES AN INFANT REQUIRES 2000 units2000 units OF CALCIPARINE. IF OF CALCIPARINE. IF STOCK AMPOULES CONTAIN STOCK AMPOULES CONTAIN 20000 units in 1 ml20000 units in 1 ml. . HOW MUCH HOW MUCH SHOULD YOU DRAW UP?SHOULD YOU DRAW UP?




2000 units2000 units 20000 units20000 units

=Volume To Be Administered

= .1 ml

X Volume

X 1mlPlease Click Slide to

Proceed


Volume Medication Example:Volume Medication Example:

IF AN ADULT PATIENT WAS ORDERED IF AN ADULT PATIENT WAS ORDERED 85mg85mg OF CORTISONE, OF CORTISONE, AND EACH STOCK AMPOULE WAS AND EACH STOCK AMPOULE WAS 5 ml5 ml AND CONTAINED AND CONTAINED

100mg100mg OF CORTISONE, OF CORTISONE, FIND THE VOLUME REQUIRED?FIND THE VOLUME REQUIRED?




85mg85mg 100mg100mg


= 4.25 ml

X Volume

X 5ml



Volume Medication Example:Volume Medication Example:A PATIENT ORDERED A PATIENT ORDERED 70mg70mg OF PETHIDINE, OF PETHIDINE, FIND THE FIND THE

VOLUMEVOLUME REQUIRED IF THE STOCK SOLUTION CONTAINS REQUIRED IF THE STOCK SOLUTION CONTAINS 10g10g OF PETHIDINE PER OF PETHIDINE PER 200ml200ml??




Conversion RequiredConversion Required

g to mg – 10g x 1000 = 10000mgg to mg – 10g x 1000 = 10000mg 70 mg70 mg 10000 mg10000 mg


= 1.4 ml

X Volume

X 200mlPlease Click Slide to

Proceed

Tablet and Volume QuizTablet and Volume Quiz

1.1. The patient is ordered Amisulpride Tablets. Order is 1200mg Mane, the The patient is ordered Amisulpride Tablets. Order is 1200mg Mane, the tablets come in 400mg. How many tablets do you administer?tablets come in 400mg. How many tablets do you administer?

2.2. The patient ordered Coversyl Plus 2.5mg Mane. Coversyl comes in The patient ordered Coversyl Plus 2.5mg Mane. Coversyl comes in 5mg Tablets. How many tablets do you give?5mg Tablets. How many tablets do you give?

3.3. A patient experiencing pain is ordered 25mg of Toradol (Ketorolac A patient experiencing pain is ordered 25mg of Toradol (Ketorolac Trometamol). The Toradol comes in 30mg/1ml. How many mls do you Trometamol). The Toradol comes in 30mg/1ml. How many mls do you draw up?draw up?

4.4. A 2 year old child is ordered Painstop (120mg Paracetamol/Codeine A 2 year old child is ordered Painstop (120mg Paracetamol/Codeine Phosphate 5mg/5ml). The child is ordered 5ml Painstop every 6 – 8 Phosphate 5mg/5ml). The child is ordered 5ml Painstop every 6 – 8 Hours. How many mls do you administer?Hours. How many mls do you administer?

5.5. A patient has returned from theatre with Nausea. The PRN order is for A patient has returned from theatre with Nausea. The PRN order is for Ondansetron IMI. The order is for 6mg, the Ondansetron comes in Ondansetron IMI. The order is for 6mg, the Ondansetron comes in 4mg/2ml. How many mls do you draw up?4mg/2ml. How many mls do you draw up?


Stock StrengthStock StrengthX Volume


Stock StrengthStock Strength=

Number Of Tablets


Tablet and Volume AnswersTablet and Volume Answers

1.1.The patient is ordered Amisulpride Tablets. Order is 1200mg The patient is ordered Amisulpride Tablets. Order is 1200mg OD, the tablets come in 400mg. How many tablets do you OD, the tablets come in 400mg. How many tablets do you administer?administer?1200mg1200mg 400mg400mg

2.2.The patient ordered Coversyl Plus 2.5mg Mane. Coversyl The patient ordered Coversyl Plus 2.5mg Mane. Coversyl comes in 5mg Tablets. How many tablets do you give?comes in 5mg Tablets. How many tablets do you give?

5mg5mg 2.5mg2.5mg

= 3 Tablets

= 1/2 Tablet



3.3.A patient experiencing pain is ordered 25mg of Toradol (Ketorolac A patient experiencing pain is ordered 25mg of Toradol (Ketorolac Trometamol). The Toradol comes in 30mg/1ml. How many mls do you Trometamol). The Toradol comes in 30mg/1ml. How many mls do you draw up?draw up?

25mg25mg

30mg30mg

4.4.A 2 year old child is ordered Painstop (120mg Paracetamol/Codeine A 2 year old child is ordered Painstop (120mg Paracetamol/Codeine Phosphate 5mg/5ml). The child is ordered 5ml Painstop every 6 – 8 Hours. Phosphate 5mg/5ml). The child is ordered 5ml Painstop every 6 – 8 Hours. How many mls do you administer?How many mls do you administer?

=X 1ml 0.8ml

5ml



5.5.A patient has returned from theatre with Nausea. The PRN order is for A patient has returned from theatre with Nausea. The PRN order is for Ondansetron IMI. The order is for 6mg, the Ondansetron comes in Ondansetron IMI. The order is for 6mg, the Ondansetron comes in 4mg/2ml. How many mls do you draw up?4mg/2ml. How many mls do you draw up?

6mg6mg

4mg4mg=X 2ml 3ml


Medication Formulas – WeightMedication Formulas – WeightWeight Calculation

mg for each Kg

Example: Child weighs 48kg the dose is 16mg for each Kg.

16mg x 48kg = 768mg/Kg required

Use formula to complete how much you need.


Medication Formulas – Weight Medication Formulas – Weight


A 5 YEAR OLD GIRL IS ORDERED PARACETAMOL STAT. THE PHARMACY A 5 YEAR OLD GIRL IS ORDERED PARACETAMOL STAT. THE PHARMACY GUIDELINES RECOMMEND GUIDELINES RECOMMEND 15mg/Kg15mg/Kg. THE CHILD WEIGHS . THE CHILD WEIGHS 18Kg18Kg. STOCK IS . STOCK IS 125mg/5ml125mg/5ml. . HOW MANY mls WILL THE CHILD RECEIVEHOW MANY mls WILL THE CHILD RECEIVE??

WEIGHT CALCULATIONWEIGHT CALCULATION

15mg for each Kg – 15 x 18 = 270mg15mg for each Kg – 15 x 18 = 270mg




270mg270mg 125mg125mg


= 10.8 ml

X Volume

X 5ml


Medication Formulas – WeightMedication Formulas – Weight


A CHILD WEIGHING A CHILD WEIGHING 16kg16kg IS ORDERED IS ORDERED 40mg/Kg/Day40mg/Kg/Day. . 4 DOSES A DAY4 DOSES A DAY, OF , OF ERYTHROMYCIN. ERYTHROMYCIN. FIND THE STRENGTH FOR A SINGLE DOSEFIND THE STRENGTH FOR A SINGLE DOSE??

Weight CalculationWeight Calculation

40mg For Each Kg – 40 X 16 = 640mg/Day40mg For Each Kg – 40 X 16 = 640mg/Day

New Calculation FormulaNew Calculation Formula

Strength Required Per DayStrength Required Per Day

Number Of Doses Per DayNumber Of Doses Per Day

640mg640mg

4 doses4 doses

= Single Dose Per Day

= 160mg for each single dose


Medication Formulas – IV InfusionsMedication Formulas – IV Infusions

Flow Rate =Volume

Time

Volume of fluid being administered Time for volume

to be infusedPlease Click Slide to

Proceed

Medication Formulas – IV InfusionsMedication Formulas – IV Infusions

Flow Rate =

Volume

Time

A PATIENT REQUIRES 1000ml FLUID OVER 8 HOURS. FIND THE FLOW RATE?

IV Infusion Calculation

1000mls

8hr

= 125mls/hr

IV Infusion Calculation Example


Medication Formulas – Iv InfusionsMedication Formulas – Iv Infusions

Flow Rate =

Volume

Time

A PATIENT IS TO RECEIVE 600ml 5% DEXTROSE IN WATER IV TO BE INFUSED OVER 4 HOURS. CALCULATE THE RATE IN mls/h TO BE DELIVERED BY PUMP?

IV Infusion Calculation

600mls

4hr

= 150mls/hr

IV Infusion Calculation Example


Weight and IV fluid Administration QuizWeight and IV fluid Administration Quiz

1. Calculate the size of a single dose if a child weighing 20 kg is ordered Flucioxacillin 100mg/kg/day. 4 doses per day?

2. Calculate the flow rate if 1.2L is to be infused over 24 hours?

3. A 5 Year Old Girl is ordered paracetamol stat. The pharmacy guidelines recommend 15mg/Kg. The child weighs 25Kg. Stock is 125mg/5ml. How many ml will the child receive?

4. A 1000ml bag of Hartman's is to be infused over 18hours. What is the flow rate?

5. A patient is ordered antibiotics. A 100mg of Metronidazol in a 100ml. It is to be infused over an hour how what is the flow rate?

VolumeVolume

TimeTimeFlow Ratemg x Kgmg x Kg =


Weight and IV fluid Administration AnswersWeight and IV fluid Administration Answers

1.1.Calculate the size of a single dose if a child weighing 20 kg is ordered Calculate the size of a single dose if a child weighing 20 kg is ordered Flucioxacillin 100mg/kg/day. 4 doses per day?Flucioxacillin 100mg/kg/day. 4 doses per day?

Weight Calculation: 20kg x 100mg = 2000Weight Calculation: 20kg x 100mg = 2000

20002000 4 doses4 doses

2.2.Calculate the flow rate if 1.2L is to be infused over 24 hours?Calculate the flow rate if 1.2L is to be infused over 24 hours?

Conversion: Litres to mls – 1.2 x 1000 = 1200mlsConversion: Litres to mls – 1.2 x 1000 = 1200mls

12001200 24 Hours24 Hours

= 500mg for each single dose

= 50 mls/hr



3.A 5 Year Old Girl is ordered paracetamol stat. The pharmacy guidelines recommend 15mg/Kg. The child weighs 25Kg. Stock is 125mg/5ml. How many ml will the child receive?Weight Calculation: 25kg x 15mg = 375mgWeight Calculation: 25kg x 15mg = 375mg

375375 125125

4.A 1000ml bag of Hartman's is to be infused over 18hours. What is the flow rate?

1000100018 Hours18 Hours

=

=

X

55.55* or 56 mls/hr

5ml 15ml



5.A patient is ordered antibiotics. A 100mg of Metronidazol in a 100ml. It is to be infused over an hour how what is the flow rate?

100mg100mg

100ml100ml= 100 mls/hr


Your TurnYour Turn1.1. A child requires 50 milligrams of Phenobarbitone. If stock A child requires 50 milligrams of Phenobarbitone. If stock

ampoules contain 200 mg in 2ml, how much will you draw ampoules contain 200 mg in 2ml, how much will you draw

up?up?

2.2. What volume is required for the injection if a patient is What volume is required for the injection if a patient is

ordered 500mg of Capreomycin Sulphate, and each stock ordered 500mg of Capreomycin Sulphate, and each stock

ampoules contains 300mg/ml?ampoules contains 300mg/ml?

3.3. A patient needs 5000mg of medication. Stock solution A patient needs 5000mg of medication. Stock solution

contains 1g per 1ml. What volume is required?contains 1g per 1ml. What volume is required?

4.4. A teenager is prescribed 1000mg of Chloramphenicol, stock A teenager is prescribed 1000mg of Chloramphenicol, stock

on hand contains 250 mg/10ml in suspension. Calculate the on hand contains 250 mg/10ml in suspension. Calculate the

volume required?volume required?Please Click Slide to

Proceed

Your TurnYour Turn5.5. How many 25mg tablets are required for a prescribed How many 25mg tablets are required for a prescribed

dose of 0.05g?dose of 0.05g?

6.6. Calculate the size of a single dose if a child weighing Calculate the size of a single dose if a child weighing

15 kg is ordered Flucioxacillin 100mg/kg/day. 4 doses 15 kg is ordered Flucioxacillin 100mg/kg/day. 4 doses

per day.per day.

7.7. 500ml is to infuse over 5 hour period. Find the flow 500ml is to infuse over 5 hour period. Find the flow

rate in ml/h?rate in ml/h?

8.8. A child weighing 45kg requires antibiotics which are A child weighing 45kg requires antibiotics which are

ordered 75mg/kg. How much will the child get in a ordered 75mg/kg. How much will the child get in a

single day if there are 3 doses a day?single day if there are 3 doses a day?Please Click Slide to

Proceed

Your TurnYour Turn9.9. An adult is to be administered 500ml of blood in An adult is to be administered 500ml of blood in

3 hours. What is the mls/hr required to 3 hours. What is the mls/hr required to

administer in the required time?administer in the required time?

10.10. A 100ml bag of Metronidazol is to be A 100ml bag of Metronidazol is to be

administered over 30minutes. What is the mls/hr administered over 30minutes. What is the mls/hr

to achieve this?to achieve this?


End of TutorialCongratulations you have completed the first part of the medications tutorial. Please email you final answer to the following email address: [email protected] and a result and certificate of completion will be emailed back. The certificate is equivalent to .5 points towards your education requirements for the year.

Upcoming Medication Tutorials will include:

• Drip Rates

• Formula for amount of fluid has been infused

• Formula for the length of time of the infusion

• Formula to find out the time it will take to infuse fluid

• Patient Controlled Analgesia calculations

mailto:[email protected]

introduction to medication calculations

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