Dosage questions

Please attempt to answer the questions before you reveal the answer. You should be spending roughly one minute per question. We have provided explained solutions at the bottom of the page.

Practice Question 1

A patient is prescribed amoxicillin 500 mg to be taken four times a day for 7 days. How many tablets should be dispensed for the entire course of treatment?

Practice Question 2

A child weighing 15 kg is prescribed a liquid medication at a dose of 10 mg/kg every 6 hours. The medication concentration is 5 mg/mL. How many milliliters should be administered per dose?

Practice Question 3

A patient weighing 70 kg is prescribed a medication at a dose of 0.1 mg/kg/day. Calculate the daily dose in milligrams.

Practice Question 4

A patient is prescribed a salbutamol inhaler with a dosage of 100 micrograms per puff. If the prescribed dose is 400 micrograms per administration, how many puffs should be taken per dose?

Practice Question 5

A patient's blood glucose level is 10 mmol/dm³. Convert this value to g/mmol.

Practice Question 6

A patient is prescribed paracetamol 500 mg tablets to be taken every 4 hours for 3 days. How many tablets should be dispensed for the entire course of treatment?

Practice Question 7

A patient requires an IV medication at a dose of 2 mg/kg/day. If the patient weighs 60 kg and the medication concentration is 10 mg/mL, how many milliliters should be administered per day?

Practice Question 8

A child weighs 18 pounds. Convert this weight to kilograms. (1 kg = 2.20462 lbs)

Practice Question 9

A patient's blood test result for cholesterol is 250 mg/dL. Convert this value to mmol/L (millimoles per liter).

Hint: Use the conversion factor of 0.0259 to convert from mg/dL to mmol/L.

Practice Question 10

A patient requires an infusion of 1000 mL of saline solution over 8 hours. Calculate the infusion rate in mL/hour.

How to solve each question

  • The patient takes 4 tablets a day and the course is 7 days long.

    4 x 7 = 28 tablets

  • First you must calculate what dosage must be.

    15 x 10 = 150mg

    The medication comes in 5mg/ml. So we divide 150 by 5 to get 30ml of medication.

  • To calculate the dose we times the dosage by the weight:

    70 x 0.1 = 7mg

  • Each puff is 100mg and the total dose is 400mg.

    400/100 = 4 puffs

    • Given:

      • Blood glucose level is 10 mmol/dm³.

    • Molar mass of glucose:

      • Molar mass of glucose (C₆H₁₂O₆) is approximately 180.16 g/mol.

    • Conversion:

      • First, convert mmol to mol:

        • 10 mmol/dm³ = 10 × 10⁻³ mol/dm³ (since 1 mmol = 10⁻³ mol)

      • Now, convert mol to grams using the molar mass:

        • 10 × 10⁻³ mol/dm³ × 180.16 g/mol = 1.8016 g/dm³

    • Adjust units to g/mmol:

      • To express the result in g/mmol, consider that 1 mmol is 10⁻³ mol, and 1 dm³ is 1000 cm³. Thus:

        • 1.8016 g/dm³ = 1.8016 g / (10⁻³ mol × 1000 cm³)

        • Simplifying gives us: 1.8016 g / 10⁻³ mol = 1801.6 g / mol

  • First you must calculate the total amount of doses:

    24 hours / 4 = 6 doses per day

    The treatment is 3 days long, therefore:

    6 x 3 = 18 doses

    18 x 1 = 18 tablets

    Note: If the patient had to take 2 tablets we would multiply by 2.

  • First we must calculate the dose:

    60 x 2 = 120 mg

    We have the medication in strength 10 mg/ml, therefore we divide by 10.

    120 / 10 = 12 ml

  • 18 / 2.20462 = 8.165

  • We are told the conversion factor. So we do:

    250 x 0.0259 = 6.475 mmol/L

  • 1000ml must be given in 8 hours. So if we divide the total amount by the amount of hours we must administer the medication in we can calculate the amount per hour.

    1000 / 8 = 125 ml/h