An ibuprofen suspension for infants contains 100 mg/5.0 mL suspension. The recommended dose is 10 mg/kg body weight. How many mL of this suspension should be given to an infant weighing 18 lb? (Assume two significant figures.)

Verified step by step guidance

1. Convert the infant's weight from pounds to kilograms using the conversion factor: 1 lb = 0.453592 kg.
2. Calculate the recommended dose in milligrams for the infant by multiplying the infant's weight in kilograms by the dose per kilogram (10 mg/kg).
3. Determine the concentration of ibuprofen in the suspension, which is given as 100 mg per 5.0 mL.
4. Calculate the volume of suspension needed by using the formula: Volume (mL) = (Recommended dose in mg) / (Concentration in mg/mL).
5. Ensure the final answer is expressed with two significant figures, as required by the problem.

Key Concepts

Dosage Calculation

Dosage calculation involves determining the appropriate amount of medication to administer based on a patient's weight. In this case, the recommended dose of ibuprofen is 10 mg per kg of body weight, which requires converting the infant's weight from pounds to kilograms to ensure accurate dosing.

Unit Conversion

Unit conversion is the process of converting a measurement from one unit to another. Here, it is necessary to convert the infant's weight from pounds to kilograms, knowing that 1 kg is approximately 2.20462 lbs. This conversion is crucial for applying the correct dosage based on the weight in kg.

Concentration of Suspension

The concentration of a suspension indicates how much active ingredient is present in a given volume. In this case, the ibuprofen suspension has a concentration of 100 mg per 5.0 mL. Understanding this concentration allows for the calculation of how many mL of suspension are needed to achieve the required dosage based on the infant's weight.