Question

A two-agent dosage regimen, termed MP, for the treatment of multiple myeloma is as follows:

Melphalan 0.25 mg/kg, PO,
D1-4/week × 6 weeks
Prednisone 2 mg/kg, PO,
D1-4/week × 6 weeks

a. Calculate the total milligrams each of melphalan and prednisone taken per week by a patient who weighs 165 lb.

b. If melphalan is available in 2-mg tablets, how many tablets are required to dose this patient for the entire treatment cycle?

c. If the patient prefers prednisone oral solution to prednisone tablets, how many milliliters of the solution (5 mg/mL) should be dispensed weekly?

Answer 1

To calculate the total milligrams of melphalan and prednisone taken per week, multiply the weight of the patient (in kg) by the dosage per kg. To find the number of melphalan tablets required for the entire treatment cycle, divide the total melphalan dosage by the dosage per tablet. To determine the milliliters of prednisone oral solution required weekly, divide the prednisone dosage per week by the concentration of the solution.

Step-by-step explanation:

To calculate the total milligrams of melphalan and prednisone taken per week by a patient weighing 165 lb:

For melphalan:
Weight of patient in kg = weight in lb / 2.2046
Weight of patient in kg = 165 lb / 2.2046 = 74.8 kg
Melphalan dosage per week = 0.25 mg/kg × 74.8 kg = 18.7 mg

For prednisone:
Prednisone dosage per week = 2 mg/kg × 74.8 kg = 149.6 mg

To calculate the number of melphalan tablets required for the entire treatment cycle:

Total melphalan dosage for the treatment cycle = melphalan dosage per week × 6 weeks = 18.7 mg/week × 6 weeks = 112.2 mg
Number of melphalan tablets required = total melphalan dosage / dosage per tablet = 112.2 mg / 2 mg = 56 tablets

To calculate the milliliters of prednisone oral solution required weekly:

Prednisone oral solution required per week = prednisone dosage per week / concentration of solution = 149.6 mg / 5 mg/mL = 29.92 mL