N232 Math

1 drop (gtt)

1 mL

Solve Using Formula •Prescription for 600 mg •Strength available 200 mg in 2.6 mL

600 mg/ 200 mg * 2.6 ml= X 600/200 *2.6=X= 7.8mL

Convert the following measurements. (Round to the nearest tenth.) Convert 6 mg to mcg ___________

6000 mcg

1 tablespoon (tbsp)

15mL

•Prescription for 30 mEq •Strength available 40 mEq in 5 mL

30 mEq/ 40 mEq* 5mL= X 30/40*5=X= 3.75=3.8 mL

1 ounce (oz)

30 milliliters (mL)

•dosage calculation: -Prescription for 20 mg -Dosage strength available 25 mg in 1.5 mL

25mg/1.5ml= 20 mg/ Xml 25X= 30 X= 1.2 ml

Other Label Information

If drug is in a multiple dose container, number of tablets or capsules in container will be on label. United States Pharmacopeia (USP) or National Formulary (NF) may be on multiple dose containers.

Average Doses

Most oral dosages consist of half to three tablets or capsules or half to double the mL volume in liquid medications

What is the NDC number?

National Drug Code An 11 digit number assigned to every medication that identifies the manufacturer, medication, and package size of the medication.

What is the trade name of a drug?

-also called brand name or proprietary name -assigned by pharmaceutical company -identifies drug as exclusive property of the company -usually does not relate to chemical nature of drug, but is catchy & easy to remember Hydrochlorothiazide

Convert the following measurements. (Round to the nearest tenth.) Convert 300 mcg to mg __________

0.3 mg

Solve Using Formula •Prescription for 0.4 mg •Strength available 0.25 mg in 1.2 mL

0.4 mg / 0.25 mg*1.2 ml= X 0.4 * 0.25* 1.2= X = 1.92 = 1.9 mL

Convert the following standard times to military time. 12:01 AM

00:01

Convert the following military times to standard time. 0215 ________

02:15am

Notation Rules

1.Quantity written in Arabic numbers: -1, 2, 3, 4, etc. -For example, 5 mL, 125 mcg, 11 cm, 62 kg, 35 mg 2.Numbers representing quantity placed before abbreviations: -For example, 3 mL, 10 kg, 6 mg, 250 mcg, 8 cm 3.Full space used between number and abbreviation: -For example, 10 mg, 100 L, 15 mcg 4.Fractional parts of unit written in decimal fractions: -For example, 34.5 mg, 2.5 mL, 78.2 kg 5.Zero placed in front of decimal point when not preceded by whole number: -Emphasizes decimal point -For example, 0.25 mg, 0.5 g 6.Excess zeros following decimal fraction deleted: For example, 4.500 g = 4.5 g; 2.500 L = 2.5 L

Dosage Calculation •Prescription for 0.5 mg •Dosage strength of 200 mcg/mL available

200 mcg : 1 mL = 0.5 mg : X mL 200 mcg : 1 mL = 500 mcg : X mL 200 X = 500 X = 2.5 mL

200 mcg/ 1mL= 0.5 mg/ X ml

200 mcg/ 1mL = 600 mcg= X mL 200 X = 500 X= 2.5mL

Convert the following standard times to military time. 10:30 PM ______

22:30

dosage calculation: -Prescription for 20 mg -Dosage strength available 25 mg in 1.5 mL

25 mg : 1.5 mL = 20 mg : X mL 25X=20*1.5 25X=30 X=1.2ml

Convert the following military times to standard time. 1445 ________

2:45pm

Convert the following measurements. (Round to the nearest tenth.) Convert 3 tbsp to mL ___________

3 tbsp * 15 ml= 45 ml

Convert the following measurements. (Round to the nearest tenth.) Convert 8 lbs. to kg ___________

3.62kg

Convert the following measurements. (Round to the nearest tenth.) Convert 4 oz. to mL ____________

4 oz. * 30 ml= 120 ml

Convert the following measurements. (Round to the nearest tenth.) Convert 4 tsp to mL ____________

4 tsp* 5 ml= 20 ml

Solve Using Formula •Prescription for 400 mcg •Strength available 0.3 mg per mL •Convert 0.3 mg to mcg to eliminate decimal point: -0.3 mg = 300 mcg

400 mcg/ 300 mcg*1 mL=X 400/300*1=X=1.33=1.3mL

1 teaspoon (tsp)

5 mL

Convert the following measurements. (Round to the nearest tenth.) Convert 5 kg to g ____________

5000 g

8mgh/1 mL= 12mg/X mL

8 X=12 , X=1.5mL

dosage calculation: -Solution strength of 8 mg per mL used to prepare dosage of 12 mg

8 mg : 1 mL = 12 mg : X mL 8 X = 12 X = 1.5 mL

Convert the following measurements. (Round to the nearest tenth.) Convert 21 lbs. 5 ounces to kg _________

9.66 kg

Formula Method "D"

= desired or dosage prescribed in mg, g, etc. -For example, if prescription for 240 mg, 240 mg is D

Medication Administration Record (MAR

A sheet used for documentation listing medications prescribed and times to be given

Liquid Oral Medications

In addition to aforementioned label information, labels for liquid oral medications state dosage strength in both: Unit of measure For example, mg, mcg, g, etc. Amount of dosage strength in mL of fluid Smaller volumes may be measured in oral or hypodermic (without needle) syringes. Larger volumes are usually measured in calibrated medication cup: 20 mL or more

500: 2 = 250: 1 500*1= 250* 2 500=500

In true proportion, product of means equals product of extremes:

Who is the manufacturer of the drug

Intas Pharmaceutical Limited

Caution

Learn to question orders for more than 3 tablets or capsules

Multiple Drug Preparations

Preparations containing multiple drugs list name and dosage of each drug. For example, Percocet™ contains oxycodone 5 mg and acetaminophen 325 mg Preparations containing multiple drugs list name and dosage of each drug. For example, Percocet™ contains oxycodone 5 mg and acetaminophen 325 mg •Tablets and capsules that contain more than one drug are usually prescribed by trade name and number of tablets/capsules to be given. -For example, Percocet™ 5 mg

Six Rights of Medication Administration

Right patient Right medication Right dose Right route Right time Right documentation

Solid Oral Drug Preparations

Tablets Scored tablets Indented marking to make breaking for partial drug dosages easier and more accurate Enteric coated tablets Delayed absorption until medication reaches small intestine Capsules Powdered or oily medications in gelatin cover Sustained or controlled-release capsules Action of medication spread over prolonged period of time

What is the generic name of a drug?

The original company who researched the drug (EX: ibuprofen)

What is the unit dose (dosage strength) of measure?

The proportion of active drug substance to excipient, measured in units of volume or concentration. (2) The strength of a drug product, which indicates the amount of active ingredient in each dosage.

Drug Label Information

Trade or brand name Capitalized Generic or official name Lowercase Strength in metric measure Always has unit of measure Manufacturers are continuing to correct the following on drug labels: "gr" for gram, which is being eliminated from use in health care Inserting a space between the dosage and the unit of measure, such as "500 mg" instead of "500 mg" •Manufacturer •Lot number •Expiration date -Must check before administering

1 tab : 50 mg= 2 tab : 100 mg 15 mg : 4 ml= 45 mg: 12m:mL

True proportion contains two ratios that are equal:

Tablet and Capsule Labels

Unit dosage label in which each tablet or capsule is packaged separately Most common label in clinical setting Each drug has only one official name but may have several trade names, created by the companies that produce them

Unnecessary Zeros

Unnecessary zeros are eliminated when metric dosages are transcribed: 2.0 mg = 2 mg, 0.20 mg = 0.2 mg

Tablet/Capsule/Oral Liquid Medication Calculation

Use basic formula: D = desired or dosage prescribed H = have/on hand Q = quantity X = unknown

Metric Conversion Chart

k(1000) h(100) da(10) GLMS d(10) c(100) m(1000) King Henry Doesn't Drink Chocolate Milk

Mg

milligram

miligram

one thousandth of a gram

Using Formula for Units Prescription for 7500 units •Strength available 10,000 units per mL

•7500 units/ 10000units* 1mL=X 7500/ 10000*1 = X = 0.75 = 0.8mL •The dosage ordered, 7500 units, is less than the strength available, 10,000 units, and must be contained in a smaller volume of the solution than 1 mL, which 0.8 mL is.

Metric/SI System

•All units of measure differ from each other in powers of 10. •Conversions between units accomplished by simply moving the decimal point. •The greatest hazard of the metric system in drug dosages is that a misplaced decimal point will alter a dosage by a multiple of at least 10.

apothecary measures

•Basically obsolete •Only measure still seen is grain (gr) -Seldom used -Equivalent to 60 mg in metric system

Right Drug

•Check every drug three times: -When drug is located -Just before opening or pouring medication -Immediately prior to administration

Right Dosage

•Compare to average dosages. •Metric dosages containing decimals are of particular concern. - Ask yourself if the dosage makes sense.

Calculations When Dosages Are in Different Measures

•Convert one measurement before solving problem. -For example, mcg and mg •Safer to convert from larger to smaller metric units of measure to eliminate decimal points. •Convert one measurement before solving problem. -For example, mcg and mg •Safer to convert from larger to smaller metric units of measure to eliminate decimal points.

Metric System /Système International (SI)

•Developed in France in 1875 •Name stems from basic unit of measure -Meter

Always remember to

•Double-check math calculations. •Use logic and reasoning when checking answer.

Medication Errors

•Estimated 100,000 people die each year from medication errors. •Occur during: -Prescribing -Transcribing Administering The major factors in nursing medication administration errors are distraction and Fatigue. •Personnel are held legally responsible if the wrong drug or dosage is given regardless of the source of error.

Milliequivalent (mEq) Measurements

•Expression of number of grams of drug in 1 mL of normal solution

Abbreviations

•Gram (g) •Milligram (mg) •Microgram (mcg) •Liter (L) which is always a capital L •Milliliter (mL) •Kilogram (kg) •Kilometer (km)

Formula Method "H"

•H = have/on-hand, or dosage strength available in mg, g, etc. -For example, if available 80 mg in 0.8 mL, 80 mg is H

Logic and Reasoning

•If prescribed dosage is smaller than available strength, X should be smaller than available volume. •If prescribed dosage is larger than available strength, X should be larger than available volume.

Ratio and Proportion Using Common Fractions

•In true proportion, products of cross multiplying are identical: 1*100= 50*2 = 100=100 •Numerators and denominators in the same unit of measure •Try the same dosage calculation: -Solution strength of 8 mg per mL used to prepare dosage of 12 mg •Notice both numerators in mg and both denominators in mL: 8mgh/1 mL= 12mg/X mL= X=1.5 ML

Percentage Measurements

•Indicate parts per hundred •Greater the percentage, stronger the solution •Used primarily in intravenous (IV) solutions •Also used in topical, ophthalmic, and optic solutions -For skin, eyes, and ears -•In solutions represent a number of grams of drug per 100 milliliters of solution. -For example, 100 mL of 5% solution contains 5 g of drug. -For example, 100 mL of a 2.5% solution contains 2.5 g of drug. •Dextrose and sodium chloride -Most common percentage dosages -Dextrose dosages are written as the whole number •For example, 5% dextrose in water (D5W) -Sodium chloride dosages are written as a decimal fraction •For example, 0.45% sodium chloride

Common Weight Units Used in Health Care

•Kilogram •Gram •Milligram •Microgram •Liter •Milliliter

Ratio Measures

•Strengths primarily used to describe solutions. •Written using Arabic numbers followed by space, colon, space, and another Arabic number. •Solution of 1:100 contains one part drug to 100 parts solution. •Represent parts of the drug per parts of the solution. •A solution that is 1 part drug in 2 parts solution would be written 1:2. •The less solution a drug is dissolved in, the stronger the solution •Ratio strengths are always expressed in their simplest terms. -For example, 2:10 would be incorrect. •It must be expressed as 1:5.

MAR Similarities

•Large column usually on the left-hand side of MAR form contains: -Drug names •Both scheduled and as needed (PRN) -Drug dosage -Frequency of drug administration •Usually three columns designated for documenting medication administration for the day, evening, and night shifts Space for precautions related to administration, such as checking:-Pulse -Blood pressure -Bodyweight •Column included for initials of person transcribing medication from an order sheet to MAR. •May include "start" and "stop" columns. -Indicate what day and time medication is to be started and stopped. •Area where all staff initials identified with full name and title •May be one sheet (front and back) or two sheets to separate scheduled and prn medications

Basic Units

•Length-Meter •Volume-Liter •Weight Gram

International Units

•Measure the drug's action. -Not weight •The word "units" is not abbreviated. The previously accepted abbreviation (U) is now on Joint Commission "Do Not Use" list •Written using Arabic numbers followed by space and word "unit". •Commas not used unless at least five digits. •For example, 6 units, 1000 units, 250,000 units. •Common medications are expressed in units. -For example, insulin and heparin

Errors

•Most errors occur because prescriptions are not properly notated or are inaccurately transcribed. •Errors usually involve decimal fractions.

Right Person

•Most important nursing intervention. •Check ID band, and read both surname and first name and birthdate. •Do this every time medication given. -No exceptions

Metric Conversions

•Move decimal point three places when units of clinical measure differ by 1000. To convert 0.5 g to mL, move the decimal three places to the right. 0.5 g = .500. mg = 500 mg •When converting from smaller to larger units in the same basic unit of measure, move the decimal point three places to the left. -For example, weight •Numerical answer will be smaller. •When converting from larger to smaller units in the same basic unit of measure, move the decimal point three places to the right. The numerical answer will be larger

Household Measures

•One of the oldest drug measurement systems •Volume measurements include ounce, tablespoon, teaspoon, and drop •Drop is an integral part of small volume medication preparation -Including those for eye, ear, and nose •Drop used almost exclusively with medications with an attached dropper

Right Route

•Oral •Sublingual -Under tongue •Drops -For the eye, ear, and nose •Topical •Transdermal •Inhalation •Creams •Suppositories •Parenteral routes -IV •Most common -Intramuscular (IM) -Subcutaneous Intradermal

Right of Refusal

•Partner with client. •If client questions medication, consider client correct until proven otherwise. •Client also has right to refuse medication.

1 mL/50mg= 2mL/100mg

•Proportion used to show relationship between two ratios:

Formula Method "Q"

•Q = quantity or volume dosage strength available contained in, such as mL or tablet For example, if available 80 mg in 0.8 mL, 0.8 mL

Safety Points

•Question any prescriptions that require unusual number of tablets or capsules. -More than three •Be mindful of errors in prescribing, transcribing, or calculating. •Some dosage strengths contain both metric and apothecary (gr) measures. Read labels carefully •Labels will not state amount of tablets/capsules or solution contained in prescribed dose. •Labels will not state amount of tablets/capsules or solution contained in prescribed dose. •When using calibrated medicine cup for liquid oral medications: -Pour safely at eye level. -Always read calibrations carefully. •Some contain several seldom-used units of measure.

Using Formula with Conversions

•Remember drug strengths must be expressed in same units of measure. -What is prescribed (D) and what is available (H) •If not, complete conversions before placing numbers in formula.

Actions When Medication Errors Occur

•Report as soon as discovered. •Institute necessary remedial measures immediately. •Determine reason for error. •Prepare incident/accident report. •Institute corrective policies/procedures to prevent recurrence, if possible.

Right Time

•Standard time. •12:00 am for midnight to 11:59 pm for one minute before midnight. •Times are duplicated during 24-hour period. -Only am and pm differentiate. •Military time •0001 for one minute after midnight to 2359 for one minute before midnight •After one o'clock in the afternoon, 12 hours added to each time until midnight -For example, 1300 = 1:00 pm, 1700 = 5:00 pm, 2200 = 10:00 pm

Ratios

•Two different numbers or quantities that have a significant relationship to each other •Can be expressed as numbers separated by a colon or as common fraction: 1ml: 50 mg= 50mg/ 1 ml •Numbers on the ends are extremes. •Numbers in the middle are means. •Mixing-up positions of extremes and means yields incorrect answer. •Ratios in proportion written in same sequence of measurement units •Each answer assessed to determine if logical

Joint Commission's "Do Not Use" List

•U -Write "unit" •IU -Write "International Unit" •QD, Q.D., q.d., or qd -Write "daily" •QOD, Q.O.D., q.o.d., or qod -Write "every other day" •MS -Write "morphine sulfate" •MSO4 or MgSO4 Write "magnesium sulfate •Omit trailing zero -For example, write X.0 mg as X mg •Use zero before decimal number -For example, write .X mg as 0.X mg

Avoiding Errors

•Use reasoning powers. Question quantities that seem unreasonable

Formula

•Variation of ratio and proportion •Formula: D/H*Q=X • -Most common initials, though others may be used For example: O(Ordered) / H(on hand)* V(vehicle)= X

Right Documentation

•When medication is administered, must be documented immediately . Never record before administered medication

Terms

•Whether larger or smaller than basic units, all other units have name of basic unit incorporated in them: -For example, kilogram, centimeter, milligram, microgram •So, the only units that can stand alone are meter, liter, and gram. •If you have just m, then it is meter. You would have to have mm for millimeter.

mEq Dosages

•Written using Arabic numbers followed by space and abbreviation mEq •Used in variety of oral and IV solutions -For example, potassium chloride most commonly used •20 milliequivalents written as 20 mEq KCl

Formula Method "X"

•X = unknown/answer or volume in which desired dosage will be contained -Amount administered after D divided by H and that answer then multiplied by Q -Based on previous examples, 2.4 mL is X •The unknown, X, will always be expressed in the same units of measure as Q, the mL volume, the dosage available is contained in.