DOSAGE CALCULATIONS. More unit conversions applied to Nursing now! 1 Tablespoon (Tbsp) = 3 Teaspoon (tsp) = 15 mL
A doctor writes an order for Lortab Elixir 5mg by mouth as needed for pain every 4 hours. Pharmacy dispenses you with 7.5mg/15ml. How many Tbsp will the nurse administer per dose?



Answer :

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Answer:

2/3 tablespoon, or 2/3 Tbsp

Explanation:

The order as written by the provider is for 5 mg Lortab Elixir PO PRN for pain q4h. This means each individual dose is 5 mg to be taken as needed by mouth every 4 hours.

In order to determine the dose to administer, the ordered amount is multiplied by the dosage strength dispensed by the pharmacy. The following formula can be used to make such calculations:

ordered amount × dosage strength = administered dose

The ordered amount is 5 mg, per the given information. The dosage strength, written as a proportion, is 7.5 mg/15 mL, meaning there are 7.5 mg of medication in 15 mL of volume. Substituting in these values can yield the value to administer.

5 mg × (15 mL / 7.5 mg)
5 mg × (2 mL / mg)
10 mg mL / mg
mg in both numerator and denominator cancel each other out, leaving mL as the unit of measurement.

The amount to be administered is 10 mL of medication.

Using the conversion factor, which is also a proportion, provided in which 15 mL is equivalent to 1 tablespoon (Tbsp), or 15 mL = 1 Tbsp, this volume can be converted to its household equivalent.

10 mL × (1 Tbsp / 15 mL)
10 mL Tbsp / 15 mL
mL in both numerator and denominator cancel each other out, leaving Tbsp as the unit of measurement.

10 Tbsp / 15 = 2/3 Tbsp

2/3 Tbsp of Lortab Elixir should be administered per dose by the nurse.

The nurse will administer 0.67 Tbsp per dose.

Determine the volume in mL needed for a 5 mg dose:  

  • 5 mg = (5 mg / 7.5 mg) * 15 mL = 10 mL

Next, convert mL to tablespoons (Tbsp):  

  • 1 Tbsp = 15 mL
  • 10 mL = 10 mL / 15 mL per Tbsp = 0.67 Tbsp