Question

Problem 4.4 Amiodarone has a volume of distribution of 4600 L. If the plasma concentration is 1 mg/L:

(a) How much drug is in the body?
(b) How much drug is in the plasma? (Assume that the volume of plasma is 3 L.)

(c) How much drug is in the tissues?
(d) What percentage of the drug in the body is in the tissues?

Problem 4.8 Nosolatol binds extensively in skeletal muscle, and the equilibrium tissue/blood ratio is 3. Assume perfusion-controlled distribution. Given that the blood perfusion to muscle is 0.02 mL/min/g:
(a) What is the distribution half-life for nosolatol in muscle?

(b) How long will it take for the drug to distribute to the muscle?

Answer 1

a.The amount of the drug concentration is calculated by the following:

C0 = X / Vd

X = total concentration of the drug.

Vd = volume of the distribution.

Vd = X / Cp

X = Cp . Vd.

X= 1 * 4600

X = 4600 mg/L.

The amount of the drug in the body was found to be 4600gm/L.

b. Cp = X /  Vd.

Cp is the plasma drug concentration.

If we assume volume of plasma is 3 L.

Cp = 4600 / 3 = 1533.33 mg/L

The amount of the drug in the plasma was found to be 1533.33 mg/L.

c. The amount of the drug in the tissues was found to be 3066.67 mg/L

Ct = X- Cp , Ct is the amount of the drug in the tissues.

= 4600 - 1533.33 = 3066.67 mg/L

D. Answer:

The percentage of the drug in the body & tissues was found to be 66.67%

Suppose X = 4600 is the 100%

then for Ct = 3066.67 ---------- ?

= 3066.67 * 100 / 4600

= 66.67%

3. a. Answer:

The distribution half-life of  nosolatol in muscle was found to be

t1/2 = 0.7 * Vd / Cl

where cl is the clearance of the drug in the m L/ min

let us consider Vd / Cl =0.02 m L/ min/g

then it gives,

t1/2 = 0.7 * 0.02

t1/2 = 0.014 mins.

b. It takes time to distribute drug to the mucle was found to be 0.028 mins.

Note: The provided answer is as per my knowledge may be or may not be 100% correct, but definitely relevant to your question thank you so much.