Systems of measurement

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Systems of measurement
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objectives

• Apothecary system
• Metric system
• Abbreviations

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Apothecary systems

• Apothecary system is one of the oldest systems of
  measurement.
• Uses fractions, as opposed to decimals.
• Is less accurate than the metric system.

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Terminology
apothecary system

• the system used by an apothecary
• a system of measurement used in pharmacy prior to
  the metric system
• units of measure include minims, fluidrams,
  scruples, grains, ounces, and pounds

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Apothecary Volume and Weight Equivalences
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Apothecary Volume and Weight Equivalences
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Apothecary Volume and Weight Equivalences
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apothecary pound 12 oz household pound 16 oz
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Conversions between the Apothecary and the Metric
Systems

• Use equivalent measures to convert between units
  in the apothecary system.
• As a general rule, convert all quantities to the
  metric system as soon as possible.

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Volume Equivalents
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Volume Equivalents
There are actually 3.75 mL in 1 fluidram.
However, convention dictates that 1 fluidram 1
tsp 5 mL.
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Volume Equivalents
There are actually 29.57 mL in 1 fluidounce, but
30 mL is usually used
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Weight Equivalents
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Weight Equivalents
Many manufacturers use 60 mg instead of 65 mg as
the equivalent for 1 grain.
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Terminology
grain
the smallest unit of measure in the apothecary
system
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Conversions between the Apothecary and the Metric
Systems

• Converting Grains
• The units of grains appears on nitroglycerin,
  along with milligram equivalent.
• Most pharmacists use 1 gr 65 mg, but some
  sources indicate 1 gr 60 mg.

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Metric system

• Kg- Kilogram
• L- Liter
• mcg- microgram
• mEq- milliequivalant
• mg- milligram
• mL- milliliter
• µg- microgram
• µgtt- micro drop
• gm-gram

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Safety Note!
Many manufacturers use 60 mg instead of 65 mg as
the equivalent for 1 grain. Read the label to
confirm the package contents.
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Conversions between the Apothecary and the Metric
Systems
Converting Fluidounces
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Remember
16 fl oz 480 1 fl oz 30 mL
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Lbs. to Kg

• There are two methods that may be used to convert
  pounds to Kg
• Lbs./ 2.2 Kg
• Therefore, if you need to convert Kg to Lbs
• Kg x 2.2 Lbs.

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Metric Conversions

• Kg, g, mg, mcg
• Lbs. to Kg
• L to mL

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Kg, g, mg, mcg

• To convert if going from large value to smaller
  value, move the decimal point 3 places to the
  right for each conversion.
• If going from smaller value to larger value, move
  the decimal point 3 places to the left for each
  conversion.
• 3.0 Kg 3000. g 3000 g
• 3.0 Kg 3000000. 3,000,000 mg
• 3.0 Kg 30000000 00.
• 3,000,000,000 mcg

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L to mL

• 1 L 1000. 1,000 mL
• 500 mL 500. .5 L

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Conversions to mg

• 300 mcg 3 mg
• 6 Kg 6,000,000 mg
• 14 g 14,000 mg
• 1,000 mcg 1 mg

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Conversions to mcg

• 1 g 1,000,000 mcg
• 0. 452 mg 452 mcg
• 0.010 mg 10 mcg
• 0.0006 Kg 600,000 mcg

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Conversions to g

• 0.043 Kg 43 g
• 100,000 mcg 0 .1 g
• 1,000 mg 1 g
• 0.075 mg 0.000075 g
• 1,500 mcg 0 .001500 g
• 1 Kg 1,000 g

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Conversions to Kg

• 1000 g 1 Kg
• 1,500 mg 0.0015 Kg
• 0.042 mg 0.000000042 Kg
• 720,000,000 mcg 0 .72 Kg

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Lbs. to Kg

• 275 Lbs. 125 Kg
• 100 Lbs. 45 Kg

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Kg to Lbs.

• 100 Kg 220 Lbs.
• 32 Kg 70 Lbs.

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L to mL

• 2 L 2,000 mL
• 0.5 L 500 mL
• 1 L 1,000 mL
• 0.250 L 250 mL

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mL to L

• 3,000 mL 3 L
• 1,500 mL 1.5 L
• 500 mL 0.5 L

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mL v. cc

• A mL and a cc have the same value.
• Therefore
• 1 mL 1 cc
• 500 mL 500 cc
• 0 .5 cc 0.5 mL

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Thank you!!