The elimination rate constant of ibuprofen is 0.1155/hr and its volumeof distribution is 0.17 L/kg. What will be the dosing regimen requiredfor a 70-kg man to achieve an average plasma concentration of 50mg/L at steady state (bioavailability is 100%)

To calculate the dosing regimen, we need to use the formula for the maintenance dose at steady state:

Maintenance dose = (Desired plasma concentration * Clearance) / Bioavailability

First, we need to calculate the clearance. Clearance is calculated by multiplying the elimination rate constant (k) by the volume of distribution (Vd).

Clearance = k * Vd

Given that k = 0.1155/hr and Vd = 0.17 L/kg, we first need to adjust Vd for the patient's weight.

Vd = 0.17 L/kg * 70 kg = 11.9 L

Now we can calculate the clearance:

Clearance = 0.1155/hr * 11.9 L = 1.37445 L/hr

Next, we can calculate the maintenance dose. Given that the desired plasma concentration is 50 mg/L and the bioavailability is 100% (or 1), we have:

Maintenance dose = (50 mg/L * 1.37445 L/hr) / 1 = 68.7225 mg/hr

Therefore, to achieve an average plasma concentration of 50 mg/L at steady state, a 70-kg man would need a dosing regimen of approximately 68.7 mg of ibuprofen per hour.