Important point:
For liquid dosages < 1 mL, round to the nearest
hundredth.
Look at the 1 mL syringe.
Notice that it is calibrated in hundredths and can accommodate
dosages rounded to the nearest hundredth.
Ex:
Order:
Codeine 25 mg IM now
Supply: vial labeled 60 mg/mL
25 mg (desired)
x 1 mL (supply) = 0.416 mL = 0.42 mL
60 mg (have)
Important point:
For liquid dosages > 1 mL, round to the nearest tenth.
Look at the 3 mL syringe.
Notice that it is calibrated in tenths and can accommodate dosages
rounded to the nearest tenth.
Ex:
Order:
Phenobarbitol 60 mg IM tid
Supply:
vial labeled 100 mg/ 2.1 mL
60 mg (desired)
x 2.1 mL (supply)
=
1.26 mL = 1.3 mL (rounded to nearest tenth)
100 mg (have)