Chapter 6 Conversions And Calculations Flashcards
Apothecary system
A system of measurement once used in the practice of pharmacy to measure both volume and weight; this system has been mostly replaced by the metric system
Avoirdupois system
A system of measurement previously used in a pharmacy for the determination of weight in ounces and pounds; this system has been mostly replaced by the metric system
Conversion factor
A fraction with the numerical value of one, which is used to convert one unit to another without changing the value of the number
Diluent/solvent
And innard product, either liquid or solid, that is added to a preparation to reduce the strength of the
Dilution
The process of adding a Diluent or solvent to a compound, resulting in a product of increased volume or wait and lower concentration
Dimensional analysis or DA
A method used to solve complicated pharmaceutical calculations that would require numerous sets of ratio and proportion problems; the main benefit of using DA is the ability to keep track of units during the process
Drip rate or DR/drop rate
The number of drops or gtt administered over a specific time via an intravenous infusion (I.e., gtt/min)
Drop factor
The size of drops coming through the tubing; the size is measured in gtt/mL and is found on the tubing package
Flow rate/infusion rate
The amount of intravenous or IV solution administered over a specific period example milliliters per minute, milliliters per hour,drops per minute; volume/time
Household system
A system of measurement commonly used in the United States; it measures volumes using household utensils
International time
A 24 hour method of keeping time; ours are not distinguished as a.m. or p.m. rather her come to continuously throughout the day example military time
International system of units or SI
A system of measurement based on seven base units with prefixes that change units buy multiples of 10; the prefixes for the modern metric system are taken from the French systeme International d’Unites and were adopted to provide a single worldwide system of weights and measures
Markup
The amount added to a wholesale price usually a percentage, to make a profit
Metric system
The approved system of measurement for pharmacy in the United States based on multiples of 10; the basic units of measurement are the gram (g) for weight, the liter (L) for volume, and the meter (m) for length
Milliequivalent (mEq)
A type of unit used in the United States to express the concentration of electrolytes such as sodium, potassium, magnesium, and calcium
Retail price
The wholesale price plus markup
Units
A unit of measurement assigned to medications called “biologicals” which have been tested for potency and biological systems; units are specific to each medication, therefore units of one medication cannot be compared to units of a different medication.
Volume
The amount of liquid enclosed within a container
Wholesale cost
The purchase price of a product in this case, medication, which is then marked up for resale
Alligation alternate
A mathematical method of solving problems that involves the mixing of two solutions or two solids with different percentage weights to achieve a desired third strength
Roman Numerals
I= 1 V= 5 X= 10 L= 50 C= 100 D= 500 M= 1000
Fahrenheit temperature of freezing
32°
Fahrenheit temperature of boiling
212°
Freezing point in Celsius
0°
Boiling point in Celsius
100°
To convert Fahrenheit to Celsius
Fraction equation:
C = (F - 32) • 5÷9
Fahrenheit to Celsius, Decimal equation
C = (F-32)/1.8
Celsius to Fahrenheit fraction equation
F= ((9•C)/5) +32
Celsius to Fahrenheit decimal equation
F=(1.8•C) +32
Solving proportion problems
Cross multiply
3/7=x/21
7x=3*21
7x=63
Teaspoon to milliliter
1 tsp = 5 mL
Tbsp to mL
1 Tbsp = 15 mL
Fluid ounce to mL
1 fl oz = 30 mL
Pint to mL
1 pt = 480 mL
Gallon to mL
1 gal = 3840 mL
Explain the apothecary measurement of grain, and the complications of using it.
The apothecary measurement of grain was dependent on the wheat crop; a successful or poor season could mean a heavier or lighter grain from one year to the next. Therefore, measurements of grain can vary between 60 mg, 64.8mg, and 65mg/gr. Codeine and nitroglycerin are measured in 60 mg/gr whereas aspirin (ASA), acetaminophen (APAP) and iron tablets are measured in 65 mg/gr.
Conversions of apothecary volume
8 fluid drams = 1 fl oz = 30 mL = 2 Tbsp
1 fluid dram = 3.7 mL (often considered to be 5mL or 1tsp, which is an approximation)
Write out the household/metric oral medicine cup measurements (7), 1/2 tsp - 2Tbs.
2 Tbs = 30mL 5 tsp = 25 mL 4 tsp = 20mL 1 Tbs = 15 mL 2 tsp = 10 mL 1 tsp = 5 mL 1/2 tsp
Write out apothecary/household oral medicine cup measurements (5), 8 dr - 1 dr.
8dr = 1 oz 6 dr = 3/4 oz 4 dr = 1/2 oz 2 dr = 1/4 oz 1 dr = 1/8 oz
