Question

A nurse is preparing to administer the first dose of tobramycin (Nebcin) to an adolescent with cystic fibrosis. The order is for 3 mg/kg I.V. daily in three divided doses. The client weighs 95 lb. How many milligrams should the nurse administer per dose? Record your answer using one decimal place.

a) 13.6 mg
b) 14.5 mg
c) 15.3 mg
d) 16.2 mg

Answer 1

To calculate the dosage of tobramycin for the adolescent, their weight in pounds is converted to kilograms, and then multiplied by the prescribed mg/kg dose. Dividing the total daily dose by three determines the mg per dose, which is 43.1 mg, not matching any of the provided options.

Step-by-step explanation:

The student's question asks for the calculation of the correct dose of tobramycin to be administered to an adolescent with cystic fibrosis. The prescribed dose is 3 mg/kg I.V. daily in three divided doses.

To convert the client's weight from pounds to kilograms, we use the conversion factor that 1 pound is approximately equal to 0.453592 kilograms. So, 95 lb is equal to 95 x 0.453592 = 43.1 kg (when rounded to the nearest tenth). Once we have the weight in kilograms, we multiply it by the prescribed dose per kilogram:
43.1 kg x 3 mg/kg = 129.3 mg daily.

Since the total daily dose should be divided into three, the amount per dose would be:
129.3 mg ÷ 3 = 43.1 mg per dose, which is not one of the options provided in the question. Therefore, it appears there may be a typo or a miscalculation in the options given by the student. The correct dose per dose, based on the provided information and calculations, is 43.1 mg.