dose is 10mg/kg IV for a 100kg patient. level drawn at level 30 minutes after the dose.
The serum level of this antibiotic returns at 83.3mg/L. What is the volume of distribution of the drug?
The goal therapeutic serum level of a is 120 mg/L. How much more drug do you need
vanco serum level drawn that returns at 37mcg/mL. She will require a redose when the level reaches 15mcg/mL. Her half-life has been determined to be 46 hours. How many hours after the initial serum draw will she require a redose.
To calculate the volume of distribution of a drug, we can use the following formula:
Volume of distribution (Vd) = Amount of Drug in the Body / Plasma Concentration of the Drug
In this case, the dose of the drug is 10mg/kg IV, and the patient weighs 100kg. So the amount of drug in the body would be:
Amount of Drug = Dose * Patient's Weight
= 10mg/kg * 100kg
= 1000mg
The serum level of the antibiotic drawn 30 minutes after the dose is 83.3mg/L. Using the formula for Vd, we can calculate:
Vd = 1000mg / 83.3mg/L
= 12 L
Therefore, the volume of distribution of the drug is 12 L.
To determine how much more drug is needed to reach the goal therapeutic serum level of 120 mg/L, we can subtract the current serum level from the target level:
Additional Drug Needed = Target Level - Current Level
= 120 mg/L - 83.3 mg/L
= 36.7 mg/L
So, you would need an additional 36.7 mg/L of the drug to reach the goal therapeutic serum level.
For the vanco serum level, the initial draw is 37mcg/mL, and the redosing threshold is 15mcg/mL. Since the half-life of vanco is known to be 46 hours, we can use this information to determine the time required for the serum level to drop to the redosing threshold.
To calculate the time needed, we can use the following equation:
Time = Half-life * Log(Current Level / Redosing Threshold)
First, let's convert the units of the serum levels into mg/L:
Current Level = 37mcg/mL * 1mg/1000mcg
= 0.037mg/mL
Redosing Threshold = 15mcg/mL * 1mg/1000mcg
= 0.015mg/mL
Using the formula for time:
Time = 46 hours * log(0.037mg/mL / 0.015mg/mL)
Using a calculator or software, we can calculate the logarithm and determine the time needed.
Please note that the formula assumes first-order elimination kinetics and steady-state conditions. It's always best to consult a healthcare professional for accurate dosing and monitoring of medications.