Menggunakan Ukur Rumah Tangga

Menggunakan Ukur Rumah Tangga (household) di Perhitungan Farmasi

What is that ?Ukuran rumah tangga (household ) adalah sistem ukuran yang digunakan di rumah-rumah , terutama di dapur. Satuan ukuran rumah tangga untuk volume termasuk sendok teh , sendokmakan, gelas, liter , dan galon . Satuan ukuran rumah tangga adalah pound dan ons. Mengukur volume atau takaran dengan menggunakan sistem ukuran rumah tangga kurang akurat daripada sistem lain karena mengukur dengan menggunakan peralatan rumah tangga dapat berbeda dalam ukuran / bervariasi. Penting untuk dicatat bahwa satuan ons dalam cairan adalah sama dalam rumah tangga dan diapotek dalam ukuran volumenya. Namun, ons digunakan untuk menandakan berat badan berbeda. Ada 12 oz dalam pound apotek, sementara ada 16 oz dalam pon rumah tangga. Satuan pound dalam ukuran rumah tangga adalah kesetaraan yang umum digunakan (Bellington, 2007).When is it appropriate?Mengukur volume dengan sistem ukuran rumah tangga dapat digunakan dalam praktik farmasi di komunitas ketika meracik obat-obatan yang akan diberikan di rumah pasien karena pasien tidak mungkin memiliki alat ukur lainnya di rumah. Tanda untuk menginstruksikan pasien tentang cara mengambil obat sering menggunakan unit ukuran rumah tangga untuk alasan ini (Ballington, 2007).How is it applicate?Seperti semua sistem, unit volume dalam ukuran rumah tangga dapat dikonversi ke yang lebih besar atau unit yang lebih kecil. Contoh berikut akan menunjukkan jenis konversi.2 tbsp = 1 fl oz1 cup = 8 fl ozBerapa banyak tablespoonsful atau sendokmakan dalam 2 cangkir obat?Mulailah solusi dengan mencatat ekuivalensi yang tepat ditunjukkan dalam Tabel ekuivalen ukuran rumahtangga

VolumeBerat

3 teaspoonsful (tsp) = 1 tablespoonful (tbsp)2 tablespoonsful (tbsp) = 1 fluid ounce (fl oz)8 fluid ounces (fl oz) = 1 cup2 cups = 1 pint (pt)2 pints (pt) = 1 quart (qt)4 quarts (qt) = 1 gallon (gal)1 pound (lb) = 16 ounces (oz)

Solusi 1: Menggunakan metode rasio-proporsi, pertama menentukan jumlahons cairan dalam 2 cangkir.

Safety Note To avoid misreadingc for c or 0, do notabbreviate cup.

Table 5.1 Household Measure Equivalents

Volume Weight

3 teaspoonsful (tsp) 5 1 tablespoonful (tbsp) 1 pound (lb) 5 16 ounces (oz)2 tablespoonsful (tbsp) 5 1 fluid ounce (fl oz)8 fluid ounces (fl oz) 5 1 cup2 cups 5 1 pint (pt)2 pints (pt) 5 1 quart (qt)4 quarts (qt) 5 1 gallon (gal)

household measure a system of measureused in homes,

volume include tea-spoonful, tablespoon-

have other measuring devices at home. Labels instructing patients on how to take amedication often use household measure units for this reason.It is important to note that the fluid ounce is the same in household and inapothecary (pharmacy) volume measure. However, the ounces used to signify weightare different. There are 12 oz in an apothecary pound, while there are 16 oz in ahousehold pound. The household pound is the more commonly used equivalence.

Converting Household Volume Measures

Like all systems, units of household volume measure can be converted to larger orsmaller units. The following examples will demonstrate this type of conversion.

How many tablespoonsful are in 2 cups of medication?

Begin the solution by noting the appropriate equivalences indicated in Table 5.1. 2 tbsp 5 1 fl oz1 cup 5 8 fl ozUsing these equivalences, the solution can be determined in two ways.

Solution 1: Using the ratio-proportion method, first determine the number offluid ounces in 2 cups.

x fl oz 5 8 fl oz 2 cups 1 cup(2 cups) x fl oz 5 (2 cups) 8 fl oz 2 cups 1 cup

x fl oz 5 16 fl ozSecond, determine the number of tablespoonsful in 16 fl oz.

x tbsp 5 2 tbsp16 fl oz 1 fl oz

(16 fl oz) x tbsp 5 (16 fl oz) 2 tbsp 16 fl oz 1 fl oz

x tbsp 5 32 tbsp

Solution 2: Using the dimensional analysis method,2 cups 3 8 fl oz 3 2 tbsp 5 32 tbsp1 cup 1 fl oz

Chapter 5 Using Household Measure in Pharmacy Calculations 96

Remember apothecary pound(lb) 5 12 oz ( )household pound5 16 oz

Example 5.1.1

How many 1 tsp doses are in 3 cups of liquid medication?

Begin the solution by noting the appropriate equivalences indicated in Table 5.1. 3 tsp 5 1 tbsp2 tbsp 5 1 fl oz8 fl oz 5 1 cupUsing these equivalences, the solution can be determined in two ways.

Solution 1: Using the ratio-proportion method, first determine the number offluid ounces in 3 cups.

x fl oz 5 8 fl oz 3 cups 1 cup(3 cups) x fl oz 5 (3 cups) 8 fl oz 3 cups 1 cup

x fl oz 5 24 fl ozSecond, determine the number of tablespoonsful in 24 fl oz.

x tbsp 5 2 tbsp24 fl oz 1 fl oz

(24 fl oz) x tbsp 5 (24 fl oz) 2 tbsp 24 fl oz 1 fl oz

x tbsp 5 48 tbspThird, determine the number of teaspoonsful in 48 tbsp.

x tsp 5 3 tsp48 tbsp 1 tbsp

(48 tbsp) x tsp 5 (48 tbsp) 3 tsp 48 tbsp 1 tbsp

x tsp 5 144 tsp

Solution 2: Using the dimensional analysis method,3 cups 3 8 fl oz 3 2 tbsp 3 3 tsp 5 144 tsp1 cup 1 fl oz 1 tbsp

97 5.1 Household Measure

Example 5.1.2

How many 1 fl oz doses are in 3 pt of liquid medication?

Begin the solution by noting the appropriate equivalences indicated in Table 5.1. 8 fl oz 5 1 cup2 cups 5 1 pt2 pt 5 1 qtUsing these equivalences, the solution can be determined in two ways.

Solution 1: Using the ratio-proportion method, first determine the number ofcups in 3 pt.

x cup 5 2 cups 3 pt 1 pt

x cup 5 6 cupsSecond, determine the number of fluid ounces in 6 cups.

x fl oz 5 8 fl oz 6 cups 1 cup

x fl oz 5 48 fl oz

Solution 2: Using the dimensional analysis method,3 pt 3 2 cups 3 8 fl oz 5 48 fl oz1 pt 1 cup

How many 1 fl oz doses are in 2 qt of liquid medication?

Begin the solution by noting the appropriate equivalences indicated in Table 5.1. 8 fl oz 5 1 cup2 cups 5 1 pt2 pt 5 1 qtUsing these equivalences, the solution can be determined in two ways.

Solution 1: Using the ratio-proportion method, first determine the number ofpints in 2 qt.

x pt 5 2 pt2 qt 1 qt

x pt 5 4 pt


Example 5.1.3Example 5.1.4

Second, determine the number of cups in 4 pt.

x cup 5 2 cups 4 pt 1 pt

x cup 5 8 cupsThird, determine the number of fluid ounces in 8 cups.

x fl oz 5 8 fl oz 8 cups 1 cup

x fl oz 5 64 fl oz

Solution 2: Using the dimensional analysis method,2 qt 3 2 pt 3 2 cups 3 8 fl oz 5 64 fl oz1 qt 1 pt 1 cup

Converting between Household Measure and the Metric System

Because of the inaccuracy of the measuring tools used in the household measure, itis often preferable to convert all quantities into the metric system. This may seemlike additional work for some problems, but using the metric system will serve youelying on the household system, which is declining in use. Prescriptionsthat are interpreted and entered into a computer as part of the patients record willneed to be converted to the metric system. Typically, such computer programs areset up to accept measurements using milliliters and grams.Although some references list exact values for conversions between the house-hold measure and the metric system, the equivalents shown in Table 5.2 are gener-ally accepted for use for these conversions in daily pharmacy practice. All of theseconversion values should be committed to memory.


Table 5.2 Household Measure and Metric System Conversion Values

Volume Weight

1 tsp 5 5 mL 1 oz 5 30 g**1 tbsp 5 15 mL 1 lb 5 454 g** 1 fl oz 5 30 mL* 2.2 lb 5 1 kg1 cup 5 240 mL1 pt 5 480 mL*1 qt 5 960 mL1 gallon 5 3840 mL

*There are actually 29.57 mL in 1 fl oz, but 30 mL is usually used. When packaging a pint, companies will typicallyinclude 473 mL, rather than the full 480 mL.**There are actually 28.34952 g in an avoirdupois ounce; however, we often round up to 30 g. It is common practice touse 454 g as the equivalent for a pound (28.35 g 3 16 oz/lb 5 453.6 g/lb, rounded to 454 g/lb).

The following examples show some typical conversion problems the pharmacytechnician must be able to solve.

You are to dispense 300 mL of a liquid preparation. If the dose is 2 tsp, howmany doses will the whole preparation contain?

Begin solving this problem by converting to a common unit of measure usingthe conversion values in Table 5.2.1 dose 5 2 tsp 5 2 3 5 mL 5 10 mLUsing these converted measurements, the solution can be determined in two ways.

Solution 1: Using the ratio-proportion method and the metric system,

x doses 5 1 dose300 mL 10 mL

(300 mL) x doses 5 (300 mL) 1 dose 300 mL 10 mL

x doses 5 30 doses

Solution 2: Using the dimensional analysis method, 300 mL 3 1 dose 5 30 doses10 mL

A patient is to purchase a 12 fl oz bottle of antacid. The patient is to take 15 mL before each meal and at bedtime. How many doses does the bottleBegin solving this problem by converting to a common unit of measure usingthe conversion values in Table 5.2.1 fl oz 5 30 mL, so 0.5 fl oz 5 15 mL, and 12 fl oz 5 360 mLUsing these converted measurements, the solution can be determined in three ways.

Solution 1: Using the ratio-proportion method and the metric system,


x dose 5 24 doses

Solution 2: Using the dimension analysis method and the metric system,360 mL 3 1 dose 5 24 doses15 mL


Example 5.1.5

Remember 1 tsp 5 5 mL

Example 5.1.6

Remember 1 fl oz 5 30 mL

Solution 3: Using the dimensional analysis method and the household system,12 fl oz 3 1 dose 5 24 doses0.5 fl oz

How many 2 tbsp doses are in 480 mL?

Using the conversion values in Table 5.2, 1 tbsp 5 15 mL. Since 1 dose equals2 tbsp, 1 dose 5 2 tbsp 5 2 3 15 mL 5 30 mLUsing these converted measurements, this problem can be solved in two ways.

Solution 1: Using the ratio-proportion method,


x dose 5 16 doses

Solution 2: Using the dimensional analysis method,480 mL 3 1 dose 5 16 doses30 mL

Theophylline elixir contains 80 mg/15 mL. A dose is 2 tbsp. How manymilligrams are in 1 dose of the theophylline elixir?

Using the conversion values in Table 5.2, 1 dose 5 2 tbsp 5 2 3 15 mL 5 30 mLThis problem can be solved in two ways.


x mg 5 80 mg30 mL 15 mL

x mg 5 160 mg

Solution 2: Using the dimensional analysis method, 30 mL 3 80 mg 5 160 mg15 mL

Like volumes, weights can be converted between household measure and metricmeasure. The most common conversions are between the household measurementsof pounds and ounces and the metric kilograms and grams. These conversions werepresented in Table 5.2.



A physician has written a prescription for a 1.5 oz tube of ointment. Howmany grams is this?

Since 1 oz equals 30 g, this problem can be solved in two ways.


x g 5 30 g1.5 oz 1 oz

x g 5 45 g

Solution 2: Using the dimensional analysis method, 1.5 oz 3 30 g 5 45 g1 oz

You have a 1 lb jar of ointment available. You are instructed to use thisstock to fill smaller jars with 20 g of ointment each. How many jars canyou fill?

Since 1 lb equals 454 g, this problem can be solved in two ways.


x jars 5 1 jar 454 g 20 g

x jar 5 22.7 jars, or 22 full jars

Solution 2: Using the dimensional analysis method, 454 g 3 1 jar 5 22.7 jars, or 22 full jars 20 g

In both solutions, there is 0.7 jar of ointment remaining. You can figure outhow many grams of ointment are leftover with the following calculation.20 g/jar 3 0.7 jar leftover ointment 5 14 g leftover ointment

Converting Body Weight

As discussed in the previous chapter, drugs are sometimes dosed based on the weightof the patient. Increasingly, drug manufacturers are providing a recommended dosebased on a specific dose in milligrams per kilogram of the patients weight. Becausemost drugs are dosed on the basis of kilograms, if a patients weight is documented inpounds, the weight will have to be converted to kilograms before calculating theappropriate dose.



Remember 30 g 5 1 oz454 g 5 1 lb

A patient weighs 134 lb. What is this patients weight in kilograms?

Since 1 kg equals 2.2 lb, this problem can be solved in two ways.


x kg 5 1 kg134 lb 2.2 lb

x kg 5 60.909 kg, rounded to 60.9 kg

Solution 2: Using the dimensional analysis method,134 lb 3 1 kg 5 60.909 kg, rounded to 60.9 kg2.2 lb

A patient weighs 76 lb. What is this patients weight in kilograms?

Since 1 kg equals 2.2 lb, this problem can be solved in two ways.


x kg 5 1 kg76 lb 2.2 lb

x kg 5 34.545 kg, rounded to 34.5 kg

Solution 2: Using the dimensional analysis method,76 lb 3 1 kg 5 34.545 kg, rounded to 34.5 kg2.2 lb

Although it is important to understand the conversion using both the ratio-proportion and the dimensional analysis methods, a shorthand method for convertinga patients weight from pounds to kilograms is to divide the amount by 2.2 lb/kg.Similarly, you can convert a patients weight from kilograms to pounds by multiplyingy 2.2 lb/kg.

A patient weighs 58 kg. What is this patients weight in pounds?

58 kg 3 2.2 lb/kg 5 127.6 lbCheck this answer by converting the answer from pounds back to kilograms.127.6 lb 3 1 kg/2.2 lb 5 58 kg

A patient in the neonatal ICU weighs 1250 g. How many pounds is this?

First, convert the grams to kilograms.1250 g 5 1.25 kg


Example 5.1.11Example 5.1.12Example 5.1.13Example 5.1.14

Remember 2.2 lb 5 1 kg

Second, convert kilograms to pounds.1.25 kg 3 2.2 lb/kg 5 2.75 lb Check the answer by converting the answer from pounds back to kilograms.2.75 lb 3 1 kg/2.2 lb 5 1.25 kg


Problem Set 5.1 3 Self-check your problem set work at www.emcp.com.

Convert the given volumes within the householdmeasure system.1. 8 cups 5 ________________________ pt2. 3 pt 5 __________________________ fl oz3. 1 pt 5 __________________________ tbsp4. 3 qt 5 __________________________ fl oz5. 28 tsp 5 ________________________ fl oz6. 1 pt 5 __________________________ qt7. 6 cups 5 ________________________ tspConvert the given volumes between the householdmeasure and metric systems.8. 80 mL 5 ________________________ tbsp9. 6 fl oz 5 ________________________ mL10. 90 mL 5 ________________________ fl oz11. 800 mL 5 _______________________ pt12. 53 mL 5 ________________________ tsp13. 35 mL 5 ________________________ tsp14. 10 L 5 __________________________ gal15. 4 tbsp 5 ________________________ mL16. 15 mL 5 ________________________ tsp17. 720 mL 5 _______________________ pt18. 30 tsp 5 ________________________ mL

19. 120 mL 5 _______________________ fl oz20. 1 2 gal 5 _________________________ mL21. 2 L 5 ___________________________ pt22. Convert the following commonly usedvolumes to milliliters.a. 3 tbsp 5 ______________________ mLb. 1 fl oz 5 ______________________ mLc. 2 fl oz 5 ______________________ mLd. 3 fl oz 5 ______________________ mLe. 4 fl oz 5 ______________________ mLf. 5 fl oz 5 ______________________ mLg. 6 fl oz 5 ______________________ mLh. 7 fl oz 5 ______________________ mLi. 8 fl oz 5 ______________________ mLj. 12 fl oz 5 _____________________ mLk. 16 fl oz 5 _____________________ mLConvert the following weights between householdmeasure and the metric system.23. 2 oz 5 __________________________ g24. 1.5 oz 5 ________________________ g25. 8 oz 5 __________________________ g26. 906 g 5 _________________________ lb

5.2 ORAL DOSES It is important that pharmacy technicians be able to perform calculations involving oraldosing of medications. Oral medications are prescribed over other dose forms wheneverpossible and appropriate because oral medications typically are safe and cost-effective.Most prescriptions taken orally come in tablet or capsule form, but liquid forms are alsocommon. Liquid medications are used most commonly by children and by adults witha disease that impairs the swallowing reflex. For all dosing calculations, accuracy ofconversions from metric to the household system, dosing amounts, and dispensingamounts need to be checked for safety as well as billing purposes.

Determining Pediatric Doses Using Dosing Tables

Not all drugs that are safe and effective for adult use are appropriate for the pediatricpopulation. In the past, formulas using the childs weight or age were used to reducethe normal adult dose to a smaller amount appropriate for the child patient. Today,prescribers are reluctant to use a medication for a child unless the pharmaceutical

105 5.2 Oral Doses

27. 30 g 5 __________________________ lb28. 0.8 oz 5 ________________________ gConvert the following patient weights from poundsto kilograms.29. 3.5 lb30. 14 lb31. 42 lb32. 97 lb33. 112 lb34. 165 lb35. 178 lb247 lb

Applications

In solving these problems, convert all quantitiesinto the metric system even when the problemcould be solved using only the household measure.37. How many 1 tsp doses are in 2 pt, 6 fl oz?38. How many 2 tsp doses are in 3 cups?39. How many 1 tbsp doses are in 12 bottlescontaining 16 fl oz each?

40. How many 5 mL doses are in a 5 fl oz bottle?41. How many 3 tsp doses are in 1 pt?42. A dose of 1.5 fl oz is to be given three timesdaily. How many milliliters will be given inone day?43. How many 11 2 tsp doses are in an 8 fl ozbottle of cough syrup?44. How many 1 tsp doses are in an 8 fl oz bottleof cough syrup?45. A medication has 15 mg/mL. How manymilligrams are given each day if the patienttakes 1 tbsp tid?46. A patient uses 1.5 fl oz of medication tid. Howmany milliliters are needed to give two doses?47. How many 1 tsp doses are in two bottlescontaining 400 mL each?48. If a medication is prescribed as 2 tsp/68 kg/dayfor an adult patient, how many doses wouldyou get in a 300 mL bottle for a patient whoweighs 180 lb?49. A medication is prescribed as 1 tsp/20 kg/dayfor a pediatric patient. How many doses will a4 fl oz bottle provide for a 52 lb patient?50. A laxative medication is prescribed as 2 tbsp/50 kg. How long will a 12 fl oz bottlelast for a patient who weighs 172 lb?

manufacturer indicates the proper dose. A manufacturer will provide specific age-and/or weight-related prescribing guidelines for pediatric-appropriate doses of aeness for the pediatric population havebeen established. These guidelines are provided in dosing tables as a dose range thats weight and/or age. When a recommended dose is notprovided, often the reason is that the Food and Drug Administration has notapproved the particular drug for use in children. The dosing tables are satisfactoryy purposes, but when a more accurate calculation is needed, either theweight-based dosing method or the body surface area (BSA) dosing method, whichwere discussed in Chapter 4, must be used.A typical

dosing table includes an age range and/or a weight range with corre-sponding doses. Dosing tables are used for both oral liquids and solid dose forms, butoral liquids are easier for young patients to take and thus are more common. Dosing tables often appear on over-the-counter (OTC) packaging for products usedfor children older than two years of age. For medications used for children under agetwo, the instruction Consult your physician appears. The table for children underage two is available to healthcare providers in pharmacies and physicians offices.ysicians often instruct parents to purchase OTC medications for small children, soappropriate dosing instructions must be provided for these patients. Dosing may needto be translated from metric units to household measure units. The dosing tables inables 5.3, 5.4, and 5.5 will be used to complete the following examples.


Table 5.3 Acetaminophen Dosing

Age Dose

03 mo 40 mg411 mo 80 mg12 yr 120 mg23 yr 160 mg45 yr 240 mg68 yr 320 mg910 yr 400 mg11 yr to adult 480 mgadult 325650 mg q46h or 1000 mg 34 times daily adult maximum 4000 mg daily

Table 5.4 Ibuprofen Dosing

Age Weight Dose

611 mo 1217 lb 50 mg1223 mo 1823 lb 75 mg23 yr 2435 lb 100 mg45 yr 3647 lb 150 mg68 yr 4859 lb 200 mg910 yr 6071 lb 250 mg11 yr 7295 lb 300 mg

dosing table a table providing doserecommendations

A 12-month-old child weighing 22 lb is to receive one dose of acetaminophen.According to the dosing information in Table 5.3, what is an appropriate dose?

Since the acetaminophen dosing is by age, not weight, use dosing for one totwo years. The appropriate dose would be 120 mg.

A parent wants to give her 15-month-old child who weighs 21 lb an appro-priate dose of OTC ibuprofen. The package provides the dosing informationin Table 5.4. What is the appropriate dose?

The dose can be determined by either age or weight, and for this child, thedosing would be the same. The appropriate dose would be 75 mg.

Dispensing Liquid Medications

Many oral liquid medications are actually solids, suspended in a liquid. Thesesuspensions are often indicated by the number of milligrams per milliliter. For exam-ple, amoxicillin is available as a 125 mg/5 mL oral liquid. In other words, 5 mL ofxicillin. Oral liquid medications are most often dosed by teaspoonsful, tablespoonsful, fluidounces, or now, in the metric system, milliliters. Being able to convert accuratelyeen household measure and the metric measure system is a necessary skill for thepharmacy technician. When calculating volumes of oral medication, it is best to converteverything into the same units. The preferred method is to use the metric system.Patient instructions will usually indicate teaspoonsful if the amount is an even half orfull teaspoon. However, the instructions should indicate milliliters if the dose is noteasily measured using the household system. An oral syringe, as shown in Figure 5.1 ishelpful to patients dosing oral liquids using the metric or household systems.Usually, an oral liquid medications written prescription includes a specificvolume to be given at each dose, as well as the total volume to be dispensed. It isimportant to have a working knowledge of the volumes of oral liquid medicationsthat are commonly prescribed. Most frequently, the dosage amount is between 2 mLand 60 mL, or roughly

1 2 tsp to 2 fl oz. Oral doses are often verified in the pharmacyby means of reference and established protocols.

107 5.2 Oral Doses

Table 5.5 Pseudoephedrine Dosing

Age Dose per Day

,2 yr 4 mg q6h25 yr 15 mg q6h612 yr 30 mg q6h12 yr to adult 3060 mg q6h


Figure 5.1 Oral Syringe This oral syringe ismarked with both

The pharmacy receives a prescription for 100 mg of amoxicillin to be takenthree times daily for 10 days. The pharmacy has a 150 mL bottle of 125 mg/5 mL amoxicillin. How many milliliters of the suspension will bedispensed, and what will the patients dosing instructions on the label say?

Determine what quantity of suspension contains 100 mg amoxicillin. This canbe solved in two ways.


x mL 5 5 mL100 mg 125 mg

x mL 5 4 mL

Solution 2: Using the dimensional analysis method,100 mg 3 5 mL 5 4 mL125 mg

Using the amount determined for a single dose, determine the total amount ofsuspension to be dispensed for 10 days.4 mL 3 3 doses/day 3 10 days 5 120 mLThe patients instructions will say, Take 4 mL three times daily for 10 days.The patient will need a dosing syringe to dispense the required amount ofmedication.

If a 12 fl oz bottle of mouthwash contains 0.75 g of the active ingredient,how many milligrams will be in a 1 tbsp dose?

Begin the problem by converting all of the household measure units to metric units. 12 fl oz 5 360 mL 1 tbsp 5 15 mLAlso, convert 0.75 g to 750 mg.Using these converted values, this problem can be solved in two ways.


x mg 5 750 mg15 mL 360 mL

x mg 5 31.25 mg



Solution 2: Using the dimensional analysis method,15 mL 3 750 mg 5 31.25 mg360 mL

The pharmacy receives a prescription for amoxicillin suspension 1 g bid.The pharmacy has a supply of amoxicillin 250 mg/5 mL. How many milli-liters are in one dose? What will the patients dosing instructions on thebottle label say?

First determine how many milligrams are needed for one dose.1 g 5 1000 mgThen determine what quantity of suspension contains 1000 mg.


x mL 5 5 mL1000 mg 250 mg

x mL 5 20 mL

Solution 2: Using the dimensional analysis method, 1000 mg 3 5 mL 5 20 mL250 mg

Translate the amount in milliliters to teaspoonsful: 5 mL 5 1 tsp, so 20 mL 5 4 tsp. The patients instructions will say, Take 20 mL (or 4 teaspoonsful) two timesdaily.

A patient is to take 7 mL of amoxicillin 250 mg/5 mL. How manymilligrams are present in one dose?


x mg 5 250 mg 7 mL 5 mL

x mg 5 350 mg

Solution 2: Using the dimensional analysis method,7 mL 3 250 mg 5 350 mg5 mL

109 5.2 Oral Doses


A patient is taking 4 tsp of diphenhydramine elixir at bedtime. He wishes totake oral tablets instead of the elixir. The 12.5 mg/5 mL elixir comes in a 4 fl oz bottle and is 14% alcohol. The 25 mg tablets come in a 1 00-countbottle. How many tablets will he need to take to equal the dose in the 4 tspof elixir?

Begin by determining the milligrams per dose of the oral liquid using one ofthe following methods.


x mg 5 12.5 mg 20 mL 5 mL

x mg 5 50 mg

Solution 2: Using the dimensional analysis method,20 mL 3 12.5 mg 5 50 mg5 mLNow, compare the milligrams to the alternative tablet product.


x tablets 5 1 tablet 50 mg 25 mg

x tablet 5 2 tablets

Solution 2: Using the dimensional analysis method,50 mg 3 1 tablet 5 2 tablets25 mgSince the patients dose is 50 mg, and the tablets come in 25 mg, he will needto take two tablets to provide the proper amount of the drug.

How many milligrams of medication are in 1 tbsp of medication thatcontains 50 mg/tsp?

Convert both volumes to the metric system using the following values from Table 5.2.1 tbsp 5 15 mL1 tsp 5 5 mLUsing these equivalences, this problem can be solved in two ways.




x mg 5 50 mg 15 mL 5 mL

x mg 5 150 mg

Solution 2: Using the dimensional analysis method,15 mL 3 50 mg 5 150 mg5 mL

Calculating the Amount to Dispense

How long the amount of medication dispensed will last the patient must be deter-mined when the prescription is entered into the patients computerized record.Pharmacies typically bill liquid medications by the milliliter and solid medications byance companies require claims for reimbursement forprescription drugs to include the amount of drug dispensed. This amount is calcu-lated by multiplying the amount of drug needed for a single day by the number ofys of treatment. Not only is this amount needed for insurance purposes, but thepharmacy also needs to ensure that the patient is receiving enough medication tolast for the duration of treatment, whether the medication is in liquid or solid form.

A patient is taking 2 tsp of medication every 8 hours. He has a 6 fl oz bottleof medication. How much medication will the patient take in one day, andhow many days will the medication last?

Begin by converting all of the stated volumes to the metric system using theconversion values in Table 5.2.1 tsp 5 5 mL; therefore, 2 tsp/dose 5 10 mL/dose1 fl oz 5 30 mL; therefore, 6 fl oz/bottle 5 180 mL/bottleNext, determine how much medication is needed for one day of treatment.The dose is every 8 hours, and there are 24 hours in a day, so 24 hr/day 3 1 dose/8 hr 5 3 doses/day3 doses/day 3 10 mL/dose 5 30 mL/dayFinally, determine the number of days the medication will last.180 mL/bottle 3 1 day/30 mL 5 6 days/bottle

A patient is to take 1 tsp of a medication twice daily, and she has a 4 fl ozbottle of medication. How much medication will the patient take in a day,and how many days will the medication last?

Begin by converting all of the stated volumes to the metric system using theconversion values in Table 5.2.1 tsp 5 5 mL; therefore, 1 tsp/dose 5 5 mL/dose1 fl oz 5 30 mL; therefore, 4 fl oz/bottle 5 120 mL/bottle

111 5.2 Oral Doses


Next, determine how much medication is needed for one day.The dose is taken twice daily, so there are 2 doses/day. 2 doses/day 3 5 mL/dose 5 10 mL/dayFinally, determine the number of days the medication will last.120 mL/bottle 3 1 day/10 mL 5 12 days/bottle

A patient has a prescription that says the following: Take Magic Coughsyrup 12 tsp every 46 hours prn cough. Disp: 8 fl oz. How many dayswill the cough syrup last?

Begin by converting all of the stated volumes to the metric system using theconversion values in Table 5.2.1 tsp 5 5 mL; therefore, 12 tsp/dose 5 510 mL/dose1 fl oz 5 30 mL; therefore, 8 fl oz/bottle 5 240 mL/bottleNext, determine how much medication is needed for one day. Assume that thepatient will take as much medication as possible as frequently as allowed. Thiswill give the minimum number of days the medication will last.There are 24 hours in a day, so if the patient takes a dose every 4 hours, 24 hr/day 3 1 dose/4 hr 5 6 doses/day6 doses/day 3 10 mL/dose 5 60 mL/dayFinally, determine the number of days the medication will last.240 mL/bottle 3 1 day/60 mL 5 4 days/bottleNote that the bottle will last longer if the patient takes 1 tsp every six hours.Some prescriptions do not come with explicit instructions as to how muchmedication is to be dispensed. The prescription may say, Take 2 tsp every morningfor 10 days. The quantity indicated on the prescription may also say QS, whichmeans to dispense a quantity sufficient to meet the needs of the patient with theinstructions given. When the duration of treatment is indicated, the amount ofmedication needed for a single day and the total amount to be dispensed can becalculated as demonstrated in the following examples.

A patient comes to the pharmacy with a prescription that does not indicatea quantity. It says, Amoxicillin 125 mg/5 mL, 1 tsp tid for 10 days. Begin by converting all of the dosage volumes to the metric system using theconversion values in Table 5.2.1 tsp 5 5 mL; therefore, 1 tsp/dose 5 5 mL/dose



Next, determine how much medication is needed for one day. Because tidmeans three times daily, 5 mL/dose 3 3 doses/day 5 15 mL/dayFinally, determine the amount of medication to dispense.15 mL/day 3 10 days 5 150 mL

A patient is to take 2 tsp of a medication four times daily for 5 days. How much will be needed?

Begin by converting all of the dosage volumes to the metric system using theconversion values in Table 5.2.1 tsp 5 5 mL; therefore, 2 tsp/dose 5 10 mL/doseNext, determine how much medication is needed for one day. 10 mL/dose 3 4 doses/day 5 40 mL/dayFinally, determine the amount of medication to dispense.40 mL/day 3 5 days 5 200 mLThe same procedure is used when calculating the number of tablets needed tofill a prescription or the number of days a given prescription will last.

A patient has brought in a prescription for an antidiabetic drug. Theprescription says, Take 2 tablets before breakfast, 1 before lunch andsupper, and 1 at bedtime. Determine the quantity needed for a 30-daysupply.

Begin by determining the number of tablets required for one day. 2 before breakfast + 1 before lunch + 1 before supper + 1 at bedtime 5 5 The patient will take 5 tablets/day, so a 30-day supply wil be5 tablets/day 3 30 days 5 150 tablets

A patient is to take a prescription for prednisone that uses a tapered dosingschedule. Determine the number of 5 mg tablets needed.

113 5.2 Oral Doses

Example 5.2.13Example 5.2.14Example 5.2.15

Prednisone 5 mg Oral Tablets

Take 40 mg for 2 daysTake 35 mg for 1 dayake 30 mg for 2 daysThen decrease by 5 mg each day until gone.

In this problem, the number of tablets taken each day changes, so the moststraightforward way to determine the number of tablets needed is to make alist of how many tablets the patient will take each day of treatment.Day 1: 40 mg/day 4 5 mg/tablet 5 8 tabletsDay 2: 40 mg/day 4 5 mg/tablet 5 8 tabletsDay 3: 35 mg/day 4 5 mg/tablet 5 7 tabletsDay 4: 30 mg/day 4 5 mg/tablet 5 6 tabletsDay 5: 30 mg/day 4 5 mg/tablet 5 6 tabletsDay 6: 25 mg/day 4 5 mg/tablet 5 5 tabletsDay 7: 20 mg/day 4 5 mg/tablet 5 4 tabletsDay 8: 15 mg/day 4 5 mg/tablet 5 3 tabletsDay 9: 10 mg/day 4 5 mg/tablet 5 2 tabletsDay 10: 5 mg/day 4 5 mg/tablet 5 1 tabletThe sum of the daily totals is 50 tablets for a 10-day regimen.


Problem Set 5.2 3 Self-check your problem set work at www.emcp.com.

Aspirin is typically contraindicated in children. If a child is unable to take acetamin-ophen or ibuprofen, however, aspirin may be used. Additionally, aspirin is indicatedfor some conditions in children such as antiplatelet therapy and antirheumatic ther-apy. Determine the milligram dose of aspirin every four hours for each child in thefollowing questions using the dosing table provided. 1. 4 years2. 7 years3. 10 years4. 14 years

Aspirin Dose (mg Age (years) Weight every 4 hr)lb kg

23 2435 10.615.9 16245 3647 1621.4 24368 4859 21.526.8 324910 6071 26.932.3 40511 7295 32.443.2 4861214 $96 $43.3 648

Levothyroxine is indicated for children with hypothyroidism. Many states requireinfants to be tested for hypothyroidism shortly after birth so that therapy can beginimmediately if needed. In adult patients, the dose is adjusted up or down based onblood titers and clinical signs and symptoms. Newborn patients are more difficult toassess, so a standard dosing table based on kilograms has been developed.Determine the daily dose of levothyroxine for each child in the following questionsusing the dosing table provided. 5. 6 lb, newborn6. 7 lb, 12 oz, newborn7. 23 lb, 11 months8. 18 lb, 15 months

115 5.2 Oral Doses

Applications

Calculate the following using either the dimensionalanalysis method or the ratio-proportion method.9. A patient takes 1 tsp daily of a medicationwith the concentration 80 mg/15 mL. Howmany milligrams are in one dose?10. A patient needs to have 60 mg of medication,and the drug has the concentration 120 mg/5 mL. How many teaspoonsful wille?11. If there are 24 mg in a teaspoonful of liquidmedication, how many grams are in 8 fl oz?12. How many milligrams are in 4 fl oz of liquidmedication with the concentration of 13. How many milligrams are in a 2 tsp dose ofliquid medication if there are 2.5 g in 2 fl oz?14. How many milligrams are in a 1 tbsp dose of liquid medication if there are 260 mg in 600 mL?

15. A prescription is received for Drug YXZ to betaken 2 tsp bid. The pharmacys supply of thew many grams areneeded to prepare 20 fl oz?16. A prescription is received for Drug YXZ to betaken 1 tbsp qam. The pharmacys supply ofthe drug is 30 mg/15 mL. How manymilligrams are in a 1 tsp dose?17. A prescription is received for Drug YXZ to betaken 1 tbsp bid. The pharmacys supply ofw many grams ofmedication are needed to prepare 1 pint?18. A patient is taking

3 4 tsp of an antibioticsuspension three times a day. How long will a 150 mL bottle of antibioticsuspension last this patient?b. How many milliliters will be left after 10 days?

Levothyroxine

Normal range Daily dose Age per day (mg) per kg (mg)

0,6 mo 7.530 2.466,12 mo 3045 3.64.815 yr 4580 33.6612 yr 6090 2.43

.12 yr .90 1.21.8

19. An antibiotic suspension is available in 80 mL,150 mL, and 200 mL bottles.a. What size bottle of antibiotic suspensionwill a patient need in order to take 1 tsptwice daily for 14 days?b. How much will remain after 14 days?20. How many days will a 12 fl oz bottle last if apatient takes 1 tbsp tid?21. A patient is on an alternate-day therapyconsisting of 2 tsp of a medication one dayand 1 tbsp the next. How long will a 300 mL22. If there are 25 mg in a tablespoonful of liquidmedication, how many grams are in 20 fl oz?23. A patient uses an antacid 1 fl oz tid and hs.How many 12 fl oz bottles will this patientneed to last 14 days?24. A mother of two children with poison ivy needsto know how many 4 fl oz bottles of antihista-mine to purchase to last 4 days. One child takes1 tsp tid and the other takes 2 tsp qid.25. How many prednisone 5 mg tablets areneeded to fill the following prescription?26. How many milliliters of nystatin must bedispensed for the following prescription?

27. There are 25 mg in a teaspoonful of medica-tion. You are dispensing 12 fl oz. a. How many milligrams will be in the bottle?b. If the patient is to get a total of 9 g for afull therapy program, how many refills will28. For the prescription below, how many fluidounces of nystatin must be dispensed?29. A prescription received reads, Take 2 tbsp ofan oral suspension three times daily for 20days. How many milliliters should beUse the label below to answer the following questions.30. How many milligrams are in

3 4 tsp?31. How many milligrams are in 1 1 2 tsp?32. How many milliliters are needed to provide125 mg?33. How many milliliters are needed to provide500 mg?


Prednisone 5 mg

Take 4 tab 3 2 daysTake 3 tab 3 2 daysTake 1 tab 3 1 day

Nystatin Suspension

use 1 mL in each cheek pouch q3h,dispense qs 10 days

Nystatin Oral Suspension

Take ii teaspoonsful 3 times dailyfor 15 days

5.3 TEMPERATURE MEASUREMENT Temperature is a factor in dealing with chemical compounds. Two temperature scalesare used to measure temperatures: the Celsius system and the Fahrenheit system.Both were developed almost 300 years ago.

Understanding Temperature Measurement Systems

Daniel Fahrenheit, a German physicist, invented an alcohol thermometer in 1709, amercury thermometer in 1714, and a temperature scale in 1724. This temperaturescale was based on ice water and salt as a low point (0 F) and the human bodyature as the high point (100 F). Fahrenheit used his own body temperatureas the standard, but in the years that followed, scientists learned that body tempera-ture varied. Therefore, the Fahrenheit scale was keyed to water for both the lowpoint and the high point. The freezing point of water at sea level was set at 32 F,ater at sea level was set at 212 F.About 1742 Anders Celsius, a Swedish astronomer, developed what became theCelsius or centigrade thermometer. In Celsius measurement, water freezes at 0 C00 C.

Converting Celsius and Fahrenheit Temperatures

Both measurement systems are in common use today. Pharmacy personnel mustknow the two systems and be able to convert back and forth between them. Theformulas for converting from one temperature measuring system to another arebased on the fact that each Celsius degree equals 1.8 or 9 5 of each Fahrenheit degree.The conversion formulas are as follows.

Celsius to Fahrenheit: F 5 9 3 C 1 32 15 2

orF 5 (1.8 3 C) 1 32

117 5.3 Temperature Measurement

Menggunakan Ukur Rumah Tangga

Documents

Transcript of Menggunakan Ukur Rumah Tangga