How to calculate tablet dosages:
This formula is used to calculate the number of tablets to be administered when given the required dose.
Required Dose
------------------
Stock Dose
= Number of tablets to be given
N.B. Units for required dose and stock dose must be the same.
Example 1:
A client is ordered 150mg of aspirin. 300 mg aspirin tablets are available. How many tablets would you give?
150 mg
------------------
300 mg
= 1/2 tablet
Example 2:
How many tablets containing 62.5 mcg will be required to give a dose of 0.125 mg?
STEP 1 : CONVERT TO SAME UNITS
Convert 0.125 mg to mcg.
The decimal place is moved 3 places to the right.
Mg - - kg hg dag g dg cg
mg
> >
µg
0.125 mg = (0.125 * 1000 mcg)
= 125 mcg
STEP 2: CALCULATE
125 mcg
------------------
62.5 mcg
= 2 tablets
OR
Convert 62.5 mcg to mg.
The decimal place is moved 3 places to the left.
Mg - - kg hg dag g dg cg
mg
< <
µg
62.5 mcg = (62.5 * 0.001 mg)
= 0.0625 mg
STEP 2: CALCULATE
0.125 mg
------------------
0.0625 mg
= 2 tablets