Injectable Drug DosagesInjectable Drug Dosages

Injectable Drug DosagesInjectable Drug Dosages

Calculating Injectable Drug DosagesChoosing Syringe Size

Insulin InjectionsTypes of InsulinInsulin LabelsMixing InsulinsMeasuring Insulin in an Insulin SyringeCombination Insulin Dosage

5. Use the formula to calculate the amount of

medication to give.

DH* Q = X

parenteral Administration of medication by some means other thanthrough the gastrointestinal tract, referring particularly to introduc-tion of substances into an organism by intravenous, subcutaneous,intramuscular, or intramedullary injection.

prefilled unit-dose syringe A sterile disposable syringe and nee-dle unit packaged by the manufacturer with a single dose of med-ication inside and ready to administer.

shaft The long portion of the needle; also known as the cannula.tuberculin syringe A narrow device calibrated in tenths and hun-

dredths of a milliliter.vial A small glass or plastic bottle intended to hold medicine.

G L O S S A R Yampule A sealed glass container that usually contains a single dose

of medicine. The top of the ampule must be broken off to open thecontainer.

bevel The pointed end of the needle that pierces the skin.cannula Long portion of the needle; also known as the shaft.desired dose The amount of medicine to be injected with a single

dose.gauge A scale of measurement used for needles.hub Portion of the needle that connects to the syringe.hypodermic syringe Device used to inject medications, available in

2, 2.5, and 3 mL sizes marked with minim and milliliter scales.insulin syringe Device imprinted with a scale specially designed for

the injection of insulin.

O B J E C T I V E SUpon completion of this chapter, the student should be able to:

1. Calculate the dosage of an injectable drug to administer.2. Select the appropriate syringe.3. Measure insulin in a matching insulin syringe.4. Compare the calibration of U-100 insulin syringe units to

milliliters (100 U � 1 mL).

O U T L I N EOverviewEquipment for Parenteral Administration

Standard Hypodermic SyringesInsulin SyringesTuberculin SyringesLarge-Capacity SyringesPrefilled Unit-Dose SyringesSafety SyringesNeedlesAmpules and Vials

1 0

1428344225, Pharmaceutical Calculations for Pharmacy Technicians: A Worktext, by Jahangir Moini, MD, MPH - ©Thomson

CHAPTER 10 Injectable Drug Dosages 105

OVERVIEW

Parenteral forms of medication are selected when a rapidresponse time to medication is desired, or if the patient isnot able to take the medication orally. Injectable drugforms may be available as a solution or a powder. Par-enteral medication can be administered via different routessuch as intravenous, intramuscular, subcutaneous, intra-dermal, epidural, subarachnoid space, and intra-articular.

Parenteral forms of medication distribute immediately.Therefore, accurate calculation of injectable drug dosagesis essential. Medication errors may cause severe impair-ment of the body organs or even loss of life.

EQUIPMENT FOR PARENTERALADMINISTRATION

To administer parenteral medications, syringes and nee-dles are used to withdraw medication from ampules (asealed glass container that usually contains a single doseof a medication) and vials (a small glass or plastic bottleintended to contain medication) (Figure 10-1). There areseveral kinds of syringes, differing in size, shape, and ma-terial. The three most commonly used types are the stan-dard hypodermic syringe, the insulin syringe, and thetuberculin syringe.

Standard Hypodermic SyringesHypodermic syringes are available in 2, 2.5, and 3 mLsizes. Syringes have three parts: the tip (or hub), whichconnects with the needle; the barrel (or outside part) onwhich the scale is printed; and the plunger, which fits in-side the barrel (Figure 10-2).

These syringes usually have two scales marked onthem: the minim and the milliliter. The milliliter scale isthe one normally used; the minim scale is used for verysmall dosages. Look closely at the metric scale in Figure10-3, which is calibrated in milliliters (mL), for each tenth(0.1) of a milliliter. Each 1/2 (or 0.5) of a milliliter ismarked up to the maximum volume of 3 milliliters.

It is important to remember to eject any extra amountof medication before injecting the patient.

Insulin SyringesAn insulin syringe is similar to a hypodermic syringe, butthe scale is specially designed for insulin: a 100-unit cali-brated scale intended for use with Unit-100 insulin. Several

1 2 1 2

2 212

3mL

Rubber plunger tipBarrel

Needle

Luerlock syringe hub Plunger

Figure 10-2. Parts of the syringe.

Figure 10-1. Injectable medications come packaged in ampulesand vials.

(A)

(B)

re, and ma-

terial. The three most commonly used types are the stan-e, and the

sed to withdrss container thation) and vi

w medication fat usually contais (a small glass

m ampu (as a single doser plastic bot

dles are ueale

of a


106 CHAPTER 10 Injectable Drug Dosages

low-dose insulin syringes are also available and frequentlyhave a nonremovable needle. It is important to know that forUnit-100 insulin, 100 units equal 1 mL. Figure 10-4 showsone side of the insulin syringe calibrated in odd-number,2-unit increments, and the other side calibrated in even-number, 2-unit increments. Figure 10-5 simulates the mea-surement of 70 units of Unit-100 insulin.

MinimScale

MetricScale

Figure 10-3. The minim and metric scales on the syringe.

Figure 10-6 shows Lo-Dose Unit-100 insulin syringes.The enlarged scale is easier to read and is calibrated foreach 1 unit up to 50 units per 0.5 mL, or 30 units per 0.3mL. Every 5 units are labeled. The 30-unit syringe is com-monly used for pediatric administration of insulin. Theplunger in Figure 10-7 simulates the measurement of 19units of U-100 insulin.

Tuberculin SyringesThe tuberculin syringe is a narrow syringe calibrated intenths and hundredths of a milliliter (up to 1 mL) on onescale and in sixteenths of a minim (up to 1 minim) on theother scale (Figure 10-8). This type of syringe can also beuseful in administering other drugs, particularly whensmall or precise measurement is indicated (e.g., pediatricdosages).

Large-Capacity SyringesSyringes are made in other sizes as well (e.g., 5, 10, 20,and 50 mL). These are not generally used to administerdrugs directly, but they can be useful for adding medica-tions to intravenous solutions or for irrigating wounds(Figure 10-9).

Prefilled Unit-Dose SyringesAnother popular type of syringe is called the prefilledunit-dose syringe. This is a sterile, disposable syringe

Figure 10-5. Standard U-100 Insulin syringe measuring 70 units of U-100 insulin.

Figure 10-4. Standard U-100 insulin syringes. (Courtesy of BD [Becton Dickinson and Company])

(A)

(B)

owse side of the insulin syringe calibrated in odd-number,

ven-Prefilled Unit-Dose Syringes

syringes are al available and que

y gand 50drugs d

ns t

e not generally y can be useful folutions or fo

mL). These ectly, but thintravenous

gsed to adminir adding medrrigating woue in



Figure 10-6. Lo-Dose U-100 insulin syringe. (Courtesy of BD [Becton Dickinson and Company])

(A)

(B)

Figure 10-7. Lo-Dose U-100 insulin syringe measuring 19 units of U-100 insulin.

(A)

(B)

Figure 10-8. Tuberculin syringe. (Courtesy of BD [Becton Dickinson and Company])



(A)

(B)

Figure 10-9. 5, 10, 30, and 60 mL syringes.

and needle packaged by the manufacturer with a singledose of medication ready to administer (Figure 10-10).Prefilled syringes contain the usual single dose of a med-ication and are to be used only once. When less than thefull single dose of a drug provided in a prefilled, single-dose syringe is administered, the syringe and its remain-ing medication should be discarded.

Safety SyringesSafety syringes have been designed in recent years to pro-tect health care workers. Figure 10-11 shows examples ofsafety syringes, where the needle is protected by a shieldor is retracted to prevent accidental needlestick injuries tothe health care worker after administering an injectablemedication.

NeedlesNeedles are made of stainless steel, and most are dispos-able. A needle has three discernible parts: the hub, whichfits onto the syringe; the cannula, or shaft, which is at-tached to the hub; and the bevel, which is the slanted part

at the tip of the needle (Figure 10-12). The gauge of theneedle refers to the diameter of the shaft; the larger thegauge number, the smaller the diameter of the shaft. Nee-dle lengths range from 1/4 inch to 5 inches.

Ampules and VialsAmpules and vials are frequently used to package sterileparenteral medications. An ampule is a glass containerusually designed to hold a single dose of a drug. It is madeof clear glass and has a distinctive shape with a constrictedneck. Ampules vary in size from 1 to 10 mL or more. Mostampule necks have colored marks around them, indicat-ing where they are prescored for easy opening.

A vial is a small glass bottle with a sealed rubber cap.Vials come in different sizes, from single to multidose.They usually have a metal or plastic cap that protects therubber seal. To access the medication in a vial, the vialmust be pierced with a needle. In addition, air must be in-jected into a vial before the medication can be withdrawn.

Several drugs (e.g., penicillin) are dispensed as pow-ders in vials. A liquid must be added to a powdered med-ication before it can be injected.

Figure 10-10. Prefilled, single-dose syringe. (Courtesy Roche Laboratories, Inc.)

drug provided in a prefilled, single-se syringe is administered, the syringe and its remain-

Am

aged by the mon ready to a

i h

anufacturer withminister (Figure

i l d

a single10-10).

at the tneedle

e (Figure 10-12)ameter of the s

th di

p of the neefers to the d

b th

The gauge of aft; the larger

f h h f N

edleme

d



(A) (B)

Figure 10-11. Safety syringes. (A) Courtesy of BD Medical Systems; (B) Courtesy of Retractable Technologies)

Shaft

Bevel

Hub

Figure 10-12. Parts of the needle.

STOP AND REVIEWSTOP AND REVIEW

Equipment for Parenteral Administration

1. Fill in the blank with the word or phrase that bestcompletes the sentence.a. Large-capacity syringes are made in various sizes,

which include_________________________________________.

b. An insulin syringe is similar to a __________ syringe.c. A hypodermic syringe usually has two scales marked

on it: the minim and the __________.d. The tuberculin syringe is a narrow syringe, calibrated

in tenths and __________ of a milliliter.

2. Determine whether the following statements are Trueor False._____a. The smaller the diameter of the needle shaft,

the larger the gauge number._____b. The 30-unit insulin syringe is commonly used

for adult patients._____c. Commonly used shaft lengths range from 1 to

4 inches._____d. A prefilled syringe contains multiple doses of

medication._____e. A vial is a small glass that has a distinctive

shape and a constricted neck._____ f. A hypodermic syringe is available in 2, 2.5, and

3 mL sizes.

Figure 10-11. Safety syringes. (A) Courtesy of BD Medical Systems; (B) Courtesy of Retractable Technologies)



CALCULATING INJECTABLE DRUG DOSAGES

Parenteral medications are measured in proper syringes.The amount of solution delivered is called the desireddose of drug. The dosage strength on an injectable drug’slabel represents the amount of medication containedwithin a volume of solution. For example, xylocaine 1%(label drug) can be interpreted as 100 mL contains 1g ofxylocaine. Another example is Compazine 5 mg/mLmeans 1 mL contains 5 mg of Compazine.

When the dosage ordered and the dose on hand havedifferent units, the dosage ordered must be converted tothe desired dose. To calculate the amount to administer,use this formula method:

D (desired)

H (have)* Q (quantity) = X (amount)

EXAMPLE 1:Measure 0.33 mL in a 1 mL syringe.

EXAMPLE 2:Round 1.33 mL to 1.3 mL, and measure in a 3 mL syringe.

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0

mL

0.33 mL

12 11

2

2 212

3mL

1.3 mL

Choosing Syringe SizeThe following rules are helpful in deciding which size sy-ringe to choose to administer parenteral dosages:

1. Round the amount to be injected (X) to tenths if theamount is greater than 1 mL, and measure it in a 3 mLsyringe.

2. Measure amounts to less than 1 mL rounded to hun-dredths and all amounts less than 0.5 mL in a 1 mLsyringe.

3. Amounts of 0.5 to 1 mL, calculated in tenths, can beaccurately measured in either a 1 mL or 3 mL syringe.

Remember

• Use this formula to calculate the amount of an injectabledrug by the formula method:

D (desired)H (have)

* Q (quantity) = X (amount)

(A)

(B)

EXAMPLE 3:Measure 0.6 mL in either a 1 mL or 3 mL syringe.(Notice that the amount is measured in tenths sothe 3 mL syringe would be preferable.)

12 11

2

2 212

3mL

0.6 mL

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0

mL

0.6 mL

.7 .8 .90000 LLLL

LEEX



An amber color has been added to selected syringedrawings throughout the text to simulate a specificamount of medication, as indicated in the example orproblem. Because the color used may not correspond tothe actual color of the medication named, it must not beused as a reference for identifying medications.

The following are some examples of parenteral dosagecalculations.

EXAMPLE 4:Measure 0.65 mL in a 1 mL syringe. (Notice thatthe amount is measured in hundredths and is lessthan 1 mL.)

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0

ML

0.65 mL

EXAMPLE 1:Ordered: Vistaril 100 mg IM statOn hand: Vistaril IM solution 50 mg / mL in a

10 mL multiple-dose vialThe amount that should be administered to thepatient:

Give intramuscularly immediately.

DH* Q =

100 mg50 mg

* 1 mL = 2 mL

(Label reproduced with permission of Pfizer, Inc.)

Select a 3 mL syringe and measure 2 mL ofVistaril 50 mg / mL. Look carefully at theillustration to clearly identify the part of the blackrubber stopper that measures the exact dosage.

12 11

2

2 212

3mL

2 mL

PLE 1:

calculatio



EXAMPLE 3:Ordered: Cleocin Phosphate 150 mg IM q12hOn hand: Cleocin Phosphate (clindamycin

injection) 300 mg / 2 mL

EXAMPLE 2:Ordered: heparin 8,000 U SC b.i.d.On hand: A vial of heparin sodium injection

10,000 units / 1 mL

given subcutaneously twice daily.

DH* Q =

8,000 U10,000 U * 1 mL =

810

mL = 0.8 mL

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0

mL

0.8 mL

12 11

2

2 212

3mL

1 mL

(Courtesy of ESI Lederle, a Business Unit of WyethPharmaceuticals, Philadelphia, PA)

Select a 1 mL or a 3 mL syringe and measure 0.8mL of heparin 10,000 U / mL. Heparin is a verypotent anticoagulant drug. It is safest to measureit in a 1 mL syringe.

given intramuscularly every 12 hours.Select a 3 mL syringe, and measure 1 mL ofCleocin 300 mg / 2 mL.

DH* Q =

150 mg300 mg

* 2 mL =22= 1 mL


8 mL

1 3 4 5

it in a

7 .9

Lm

LLLy



EXAMPLE 4:Ordered: Robinul 150 mcg IM statOn hand: Robinul 0.2 mg / mL0.2 � 1000 � 0.200. � 200 mcg

�

Equivalent : 1 mg � 1000 mcg

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0

mL

0.75 mL

given intramuscularly immediately.Select a 1 mL syringe, and measure 0.75 mL ofRobinul 0.2 mg / mL.

DH* Q =

150 mcg200 mcg

* 1 mL =34= 0.75 mL

(Courtesy of ESI Lederle, Philadelphia, PA)

EXAMPLE 5:Ordered: morphine sulfate gr 1/6 IM q3–

4h p.r.n.The label on the dosette vial states morphinesulfate 10 mg / mL.On hand: morphine sulfate 10 mg / mLEquivalent: gr i � 60 mg

(Courtesy of Baxter Healthcare Corporation)

7 8

m

g en intramuscularly iect a 1 mL syringe,

* Qmcg

*

75 mL of

mL

mediately.nd measure 0

L4




Calculating Desired Dose and Choosing the Correct Syringe

1. Calculate the amount you will prepare for each dose. The labels provided represent the drugs available. Draw an arrow tothe syringe calibration that corresponds to the amount you will administer. Indicate doses that have to be divided.a. Ordered: potassium chloride 15 mEq added to each 1000 mL IV fluids

Give: __________ mL

given intramuscularly every 3 to 4 hours asneeded for pain.

DH* Q =

10 mg10 mg

* 1 mL = 1 mL

gr16*

601= 10 mg

12 112

2 212

3mL

1 mL

1 2 3 4 5 6 7 8 9 10 mL

(Courtesy of American Pharmaceutical Partners, Inc.)

b. Ordered: Tigan 200 mg IM stat, then 100 mg q6h p.r.n., nauseaGive: __________ mL stat and __________ mL q6h

12 11

2

2 212

3mL

stat DOSE

12 11

2

2 212

3mL

q.6h p.r.n. DOSE(Courtesy of Monarch Pharmaceuticals)



c. Ordered: methotrexate 30 mg IM q.d. � 5 daysGive: __________ mL

d. Ordered: Vitamin B12 0.5 mg IM once / weekGive: __________ mL

12 11

2

2 212

3mL


e. Ordered: furosemide 15 mg IM q.d.Give: __________ mL

12 11

2

2 212

3mL


12 11

2

2 212

3mL


f. Ordered: Vistaril 20 mg IM q4h p.r.n., nauseaGive: __________ mL

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0

mL

(Label reproduced with permission of Pfizer, Inc.) (continues)

122

1



g. Ordered: Bumex 500 mcg IV bolus statGive: __________ mL

(continued)

12 11

2

2 212

3mL

h. Ordered: digoxin 600 mcg IV statGive: __________ mL

(Courtesy of Hoffman-LaRoche)

i. Ordered: Depo-Provera 1 g IM statGive: __________ mL

12 11

2

2 212

3mL

(Reproduced with permission of GlaxoSmithKline)

12 11

2

2 212

3mL

(Courtesy of Pharmacia Corporation, Peapack, NJ)



j. Ordered: Bicillin CR 900 / 300 2,400,000 U IM statGive: __________ mL

0.5 mL 1 mL 1.5 mL 2 mL

0.5 mL 1 mL 1.5 mL 2 mL

k. Ordered: Terramycin 150 mg IM q12hGive: __________ mL

(Copyright Eli Lilly and Company. Used with permission.)

12 11

2

2 212

3mL

l. Ordered: heparin 4500 USC q.d.Give: __________ mL


.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0

mL

(Courtesy of ESI Lederle, a Business Unit of Wyeth Pharmaceuticals, Philadelphia, PA)



INSULIN INJECTIONS

Insulin is a hormone released from the pancreas. It is es-sential for glucose, proteins, and fat metabolism. Patientswho suffer from insulin-dependent diabetes are requiredto receive insulin injections each day. Insulin is measuredin units (U) and the most frequent supply dosage is 100U per mL. U-100 is the abbreviation of 100 U per mL.

Pharmacy technicians must remember that accuracy ininsulin preparation and administration is critical. Poten-tially life-threatening situations may result from inaccu-racy of the measurement. The information on the insulinlabel must be correctly interpreted and the correct size sy-ringe must be selected for administration of insulin. Theseare the two most important factors for the pharmacy tech-nician to understand regarding insulin injections.

Types of InsulinThere are several sources of insulin, which include:

1. Human insulin (the most common type)a. Biosynthetic—bacteria genetically altered to cre-ate human insulinb. Semisynthetic—pork insulin chemically alteredto produce human insulin

2. Beef insulin—from the pancreas of a cow3. Pork insulin—from the pancreas of a pig4. Beef-pork mixture—a combination of beef and pork

insulin (this type of insulin is being phased out)

Timing of Action

Insulins are classified by the timing of their action. Figure10-13 illustrates a sampling of insulin labels arranged bythe three action times:

� Rapid-acting (Regular, Lispro)� Intermediate-acting (Lente, NPH, or Neutral

Protamine Hagedorn)� Long-acting (Ultralente)

Figure 10-13. Labels for insulin types grouped by action types. (Copyright Eli Lilly and Company. Used with permission and Courtesy ofNovoNordisk)

(A)

(B)

(C)

(D)

(E)

(F)

(G)

� L)

ralente)amine Ha

ng-acting (U



The two most common types of insulin used are Regularand NPH insulin. You can see the uppercase, bold letterson each insulin label as follows: R for Regular insulin; Lfor Lente insulin; N for NPH insulin; and U for Ultralenteinsulin. These letters are important visual identifiers whenselecting the insulin type.

Insulin LabelsInsulin labels are identified by the manufacturer, thebrand and generic names, storage information, the supplydosage or concentration, and the expiration date (Figure10-14).

Mixing InsulinsTwo premixed insulin combinations that are commerciallyavailable are 70 / 30 U-100 insulin and 50 / 50 U-100 in-sulin (Figure 10-15). The 70 / 30 insulin concentrationmeans there are 70% NPH insulin and 30% Regular in-sulin in each unit. Therefore, if the prescriber orders 10units of 70 / 30 insulin, the patient would receive 7 unitsof NPH insulin (70% or 0.7 � 10 U � 7 U) and 3 units ofRegular insulin (30% or 0.3 � 10 U � 3 U) in the 70 / 30concentration.

The 50 / 50 insulin concentration means there are 50%NPH insulin and 50% Regular insulin in each unit. There-fore, if the physician orders 16 units of 50 / 50 insulin, thepatient would receive 8 units of NPH insulin (50% or 0.5� 12 U � 8 U) and 8 units of Regular insulin (50% or 0.5� 16 U � 8 U).

Brand Name

Generic Name

Supply Dosage/Concentration

Manufacturer Storage

Species

Expiration DateType

Total Volume of Container

Figure 10-14. Insulin label. (Copyright Eli Lilly and Company.Used with permission.)

Figure 10-15. Premixed, combination insulins. (Copyright Eli Lillyand Company. Used with permission; Courtesy of NovoNordisk)

(A)

(B)

Measuring Insulin in an Insulin SyringeMeasuring insulin with the insulin syringe is quite simple.The insulin syringe obtains a correct dosage without math-ematical calculation. They are the standard (100-unit) ca-pacity and the lo-dose (50-unit and 30-unit) capacities.

Standard U-100 Insulin Syringe

The Standard U-100 insulin syringe in Figure 10-4 is adual-scale syringe with 100 U / mL capacity. It is calibratedon one side in even-numbered, 2-unit increments (2, 4, 6. . .) with every 10 units labeled (10, 20, 30 . . .). It is cal-ibrated on the reverse side in odd-numbered, 2-unit in-crements (1, 3, 5 . . .) with every 10 units labeled (5, 15,25 . . .). The measurement of 73 units of U-100 insulin isshown in Figure 10-16.

Lo-Dose U-100 Insulin Syringes

The Lo-Dose U-100 insulin syringe in Figure 10-6 is asingle-scale syringe with 50 U / 0.5 mL capacity. It is cali-brated in 1-unit increments with every 5 units (5, 10, 15 . . .) labeled up to 50 units. The enlarged 50-unit cali-bration of this syringe makes it easy to read 32 units. Tomeasure 32 units, withdraw U-100 insulin to the 32-unitmark (Figure 10-17).

10 20 30 40 50 60 70 80 90 100

UN

ITS

USE U-100 ONLY

5 15 25 35 45 55 65 75 85 95 (Opposite Side)

Figure 10-16. Standard U-100 insulin syringe measuring 73 units.

lin labels are identified by the manufacturer, thethe sup

ematical calculation. They are the standard (10

nsu for hese letters arehe insulin typ

H insulin; anmportant visual

U for Ultralenteentifiers when

nsulin in an Ineasuring I ulin Syringe

for Lentensuelec

unit

t) caes



The Lo-Dose U-100 insulin syringe is also shown inFigure 10-6. This is another single-scale syringe with30 U / 0.3 mL capacity. It is calibrated in 1-unit incre-ments with every 5 units (5, 10, 15 . . .) labeled up to30 units. The enlarged 30-unit calibration accuratelymeasures very small amounts of insulin, such as for chil-dren. To measure 12 units, withdraw U-100 insulin to the12-unit mark (Figure 10-18).

Combination Insulin DosageSome patients may use two types of insulin that has beenordered to be administered at the same time. To avoid in-jecting the patient twice, it is common practice to draw upboth insulins in the same syringe.

EXAMPLE 1:Ordered: Novolin R Regular U-100 insulin 12

U with Novolin N NPH U-100insulin 40 U SC with breakfast

To accurately draw up both insulins into the samesyringe, the pharmacy technician must know thetotal units of both insulins: 12 � 40 � 52 units.Withdraw 12 units of the Regular U-100 insulin(clear) and then withdraw 40 more units of theNPH U-100 insulin (cloudy) up to the 52-unitmark (Figure 10-19). In this case, the smallestcapacity syringe that can be used is the StandardU-100 insulin syringe.

5 10 15 20 25 30 35 40 45 50 UN

ITSUSE U-100 ONLY

Figure 10-17. 50 U Lo-Dose U-100 insulin syringe measuring 32 units.

5 10 15 20 25 30 UN

ITSUSE U-100 ONLY

Figure 10-18. 30 U Lo-Dose U-100 insulin syringe measuring 12 units.

12 unitsRegularU-100 insulin

40 unitsNPH

U-100 insulin

Total insulin dosage = 52 units

10 20 30 40 50 60 70 80 90 100

UN

ITS

USE U-100 ONLY

5 15 25 35 45 55 65 75 85 95 (Opposite Side)

Figure 10-19. Combination insulin dosage. (Courtesy of Novo Nordisk)

(A)

(C)(B)

(clear) and then withdraw 40 more units of the

ynlarged 30-u

mall amounts o12 units, with

)it calibration ainsulin, such asraw U-100 ins

pcuratelyor chil-n to

ulin 40 U SC wraw up both insurmacy technici

o accurately yringe, the p

h breakns into the sammust know the

units. Thees vo me



The second example gives step-by-step directions forthis procedure. Look closely at Figures 10-20 and 10-21to demonstrate the procedure as you study Example 2.Notice that to withdraw Regular insulin (clear) first andthen NPH insulin (cloudy), you must inject the doseamount of air into the NPH insulin before you inject thedose amount of air into the Regular insulin.

5101520253035404550 UNITS

US

E U

-100

ON

LY

1)Inject 30 Uair

2)Inject 10 Uair

3)Withdraw10 U Regular

4)Withdraw30 U NPHfor a total of40 U

NovolinN

U-100Novolin

R

U-100

NovolinU-100

RNovolinU-100

N

5101520253035404550 UNITS

US

E U

-100

ON

LY

5101520253035404550

UNITS

US

E U

-100 ON

LY

5101520253035404550

UNITS

US

E U

-100 ON

LY

Figure 10-20. Procedure for drawing up combination insulin dosage: 10 U Regular U-100 insulin with 30 U NPH U-100 insulin.

EXAMPLE 2:A prescriber orders Novolin R Regular U-100insulin 10 U with Novolin N NPH U-100 insulin30 USC 1/2 hour before dinner.1. Draw back and inject 30 units of air into the NPH

insulin vial (cloudy liquid). Remove the needle.

2. Draw back and inject 10 units of air into theRegular insulin (clear liquid) and leave theneedle in the vial.

3. Turn the vial of Regular insulin upside down,and draw out the insulin to the 10-unit markon the syringe. Make sure all air bubbles areremoved.

4. Roll the vial of the NPH insulin in your hands tomix; do not shake it. Insert the needle into theNPH insulin vial, turn the vial upside down andslowly draw back to the 40-unit mark, beingcareful not to exceed the 40-unit calibration.10 units of Regular � 30 units of NPH � 40units of insulin total (see Figure 10-21).

R



10 unitsNovolin R RegularU-100 Insulin

30 unitsNovolin N NPH

U-100 Insulin

Total insulin dosage = 40 units5 10 15 20 25 30 35 40 45 50 UN

ITS

USE U-100 ONLY

Figure 10-21. Combination insulin dosage.


Calculating Insulin Doses

1. Read the following labels. Identify the insulin brandname and its action time (rapid-acting, intermediate-acting, or long-acting).a. Insulin brand name __________

Action time __________





(Courtesy of Novo Nordisk)

b. Insulin brand name __________Action time __________

c. Insulin brand name __________Action time __________

d. Insulin brand name __________Action time __________

e. Insulin brand name __________Action time __________

f. Describe the three syringes available to measure U-100 insulin.__________________________________________

g. What would be your preferred syringe choice tomeasure 24 units of U-100 insulin?__________________________________________

h. What would be your preferred syringe choice tomeasure 35 units of U-100 insulin?__________________________________________

i. There are 60 units of U-100 insulin per _____ mL.j. There are 25 units of U-100 insulin per _____ mL.k. 65 units of U-100 insulin should be measured in a(n)

____________ syringe.l. The 50 unit Lo-Dose U-100 insulin syringe is intended

to measure U-50 insulin only. ______(True or False)



2. Identify the U-100 insulin dosage indicated by the colored area of the syringe.a. __________ U

10 20 30 40 50 60 70 80 90 100

UN

ITS

USE U-100 ONLY

5 15 25 35 45 55 65 75 85 95 (Opposite Side)

b. __________ U

5 10 15 20 25 30 UN

ITS

USE U-100 ONLY5 10 15 20 25 30 35 40 45 50

UN

ITS

USE U-100 ONLY

10 20 30 40 50 60 70 80 90 100

UN

ITS

USE U-100 ONLY

5 15 25 35 45 55 65 75 85 95 (Opposite Side)

10 20 30 40 50 60 70 80 90 100

UN

ITS

USE U-100 ONLY

5 15 25 35 45 55 65 75 85 95 (Opposite Side)

5 10 15 20 25 30 UN

ITS

USE U-100 ONLY

10 20 30 40 50 60 70 80 90 100

UN

ITS

USE U-100 ONLY

5 15 25 35 45 55 65 75 85 95 (Opposite Side)

5 10 15 20 25 30 UN

ITS

USE U-100 ONLY

5 10 15 20 25 30 35 40 45 50U

NIT

S

USE U-100 ONLY

c. __________ U

d. __________ U

3. Draw an arrow on the syringe to identify the given dosages.a. 80 units U-100 insulin

b. 15 units U-100 insulin

c. 66 units U-100 insulin

d. 16 units U-100 insulin

e. 32 units of U-100 insulin

(continues)

10 3 4010 0 7070707070 80 9050

0000 TSITTT



(continued)

4. Draw arrows and label the dosage for each of the combination insulin orders to be measured in the same syringe. Label andmeasure the insulins in the correct order, indicating which insulin will be drawn up first.a. Novolin R Regular U-100 insulin 21 U with Novolin N NPH U-100 insulin 15 U SC stat

5 10 15 20 25 30 35 40 45 50U

NIT

S

USE U-100 ONLY

10 20 30 40 50 60 70 80 90 100

UN

ITS

USE U-100 ONLY

5 15 25 35 45 55 65 75 85 95 (Opposite Side)

10 20 30 40 50 60 70 80 90 100

UN

ITS

USE U-100 ONLY

5 15 25 35 45 55 65 75 85 95 (Opposite Side)

5 10 15 20 25 30 UN

ITS

USE U-100 ONLY

b. Humulin R Regular U-100 insulin 16 U with Humulin N NPH U-100 insulin 42 U SC stat

c. Humulin R Regular U-100 insulin 32 U with Humulin N NPH U-100 insulin 40 U SC with dinner

d. Humulin R Regular U-100 insulin 8 U with Humulin N NPH U-100 insulin 12 U SC stat

T E S T Y O U R K N O W L E D G ET E S T Y O U R K N O W L E D G ECalculate one dose of each of the drug orders numbered 1 through 12. Draw an arrow on the syringe, indicating thecalibration line that corresponds to the dose to be administered. The labels provided following these questions arethe drugs that are on hand. Indicate dosages that must be administered.

1. Haldol 1.5 mg IM q8hGive: __________ mL

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0

mL

(Courtesy of Ortho-McNeil Pharmaceuticals)

101010101 2 30 0 50 60 70 80 90

10TS

UN

ITTT1



2. Thorazine 40 mg IM q6hGive: __________ mL

12 11

2

2 212

3mL

(Courtesy of GlaxoSmithKline)

3. Inapsine 1 mg IV stat.Give: __________ mL

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0

mL

(Courtesy of Akorn Inc)

4. Nebcin 100 mg IM q8h.Give: __________ mL

12 11

2

2 212

3mL


5. Epoetin alpha 12,000 U SC q.d. � 10 daysGive: __________ mL

12 11

2

2 212

3mL

(Courtesy of Amgen Inc.)(continues)



(continued)

6. Humulin Regular U-100 insulin 22 USC statGive: __________ U

5 10 15 20 25 30 35 40 45 50 UN

ITS

USE U-100 ONLY

10 20 30 40 50 60 70 80 90 100

UN

ITS

USE U-100 ONLY

5 15 25 35 45 55 65 75 85 95 (Opposite Side)


7. Meperidine 60 mg IM q3–4h p.r.n., painGive: __________ mL

12 11

2

2 212

3mL


8. Phenergan 15 mg IM q3–4h p.r.n., nausea and vomitingGive: __________ mL

12 11

2

2 212

3mL

(Courtesy of ESI Lederle, a Business Unit of Wyeth Pharmaceuticals,Philadelphia, PA)

22 22 mL



9. Reglan 7 mg IM statGive: __________ mL

12 11

2

2 212

3mL

(Courtesy of A-H Robins Pharmaceuticals)

10. Neupogen 225 mcg SC q.d. � 2 weeksGive: __________ mL

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0

mL

(Courtesy of Amgen Inc)

11. Novolin R Regular U-100 insulin 32 U with Novolin N NPH U-100 insulin 54 U SC with breakfast.Give: __________ U

10 20 30 40 50 60 70 80 90 100

UN

ITS

USE U-100 ONLY

5 15 25 35 45 55 65 75 85 95 (Opposite Side)

(Courtesy of Novo Nordisk)(continues)



(continued)

12. Novolin 70 / 30 U-100 insulin 46 U SC with dinner.Give: __________ U

5 10 15 20 25 30 35 40 45 50 UN

ITS

USE U-100 ONLY

(Courtesy of Novo Nordisk)

Calculate the amount you will prepare for one dose.Indicate the syringe you will select to measure themedication.

13. Ordered: Demerol 35 mg IM q4h p.r.n., painOn hand: Demerol 50 mg / 1 mLGive: __________ mL Select: __________ syringe

14. Ordered: Atarax 40 mg IM q4–6h p.r.n., agitationOn hand: Atarax 50 mg / mLGive: __________ mL Select: __________ syringe

15. Ordered: Garamycin 40 mg IM q8hOn hand: Garamycin 80 mg / 2 mLGive: __________ mL Select: __________ syringe

16. Ordered: heparin 3500 U SC q12hOn hand: heparin 5000 U / mLGive: __________ mL Select: __________ syringe

17. Ordered: Lasix 60 mg IV statOn hand: Lasix 20 mg per 2 mL ampuleGive: __________ mL Select: __________ syringe

18. Ordered: Phenergan 35 mg IM q4h p.r.n., nausea andvomiting

On hand: Phenergan 50 mg / 1 mLGive: __________ mL Select: __________ syringe

19. Ordered: vitamin B12 0.75 mg IM q.d.On hand: vitamin B12 1000 mcg / mLGive: __________ mL Select: __________ syringe

20. Ordered: lidocaine 50 mg IV statOn hand: lidocaine 2%Give: __________ mL Select: __________ syringe

21. Ordered: morphine sulfate gr 1/4 IM statOn hand: morphine sulfate 10 mg / mLGive: __________ mL Select: __________ syringe

22. Ordered: Cleocin 300 mg IM q.i.d.On hand: Cleocin 0.6 g / 4 mLGive: __________ mL Select: __________ syringe

23. Ordered: Dilantin 25 mg IV q8 hOn hand: Dilantin 100 mg / 2 mL ampuleGive: __________ mL Select: __________ syringe

24. Ordered: heparin 6000 U SC q12hOn hand: heparin 10,000 U / mL vialGive: __________ mL Select: __________ syringe

25. Ordered: atropine gr 1/150 IM on call to O.R.On hand: atropine 0.4 mg / mLGive: __________ mL Select: __________ syringe

26. Ordered: Thorazine 10 mg deep IM q.i.d.On hand: Thorazine 25 mg / mLGive: __________ mL Select: __________ syringe

27. Ordered: Epogen 1400 U SC tiwOn hand: Epogen 2000 U / mLGive: __________ mL Select: __________ syringe

28. Ordered: Adrenalin 0.2 mg SC statOn hand: Adrenalin 1 : 2000 solutionGive: __________ mL Select: __________ syringe

29. Ordered: Brethine 0.25 mg SC statOn hand: Brethine 1 mg / mLGive: __________ mL Select: __________ syringe



30. Ordered: magnesium sulfate 250 mg IM q.d.On hand: magnesium sulfate 10% solutionGive: __________ mL Select: __________ syringe

31. Ordered: Calciferol 24,000 IU IM q.d.On hand: Calciferol 500,000 IU / 5 mLGive: __________ mL Select: __________ syringe

32. Ordered: Robinul 0.15 mg IM statOn hand: Robinul 0.2 mg / mLGive: __________ mL Select: __________ syringe

CRITICAL THINKING

1. Describe how to prevent a medication error in the fol-lowing example.A patient presents with nausea, and a physician ordersoral Compazine liquid. Due to the patient’s difficultyin taking the medication normally, the physician hasinstructed that a needleless syringe be supplied alongwith the medication, which the patient can use to self-administer the medication. The pharmacy technicianprocessing the order accidentally packages it withneedles so that the medication may be self-injected,along with appropriate self-injection instructions.If the patient followed these instructions, and did self-inject the medication, how would the medication be ab-sorbed? What could possibly develop at the site of theinjection as a result?


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