Effect of the pharmacokinetic parameters
on the drug distribution between the central
and peripheral compartments (Cont'd)

c - First-order transfer rate constant, k21

Examine the drug amount-time profiles in the central and peripheral compartments after a single iv administration of the same dose when only k21 is different.

Peripheral
compartment

k21

k12

iv

Central
compartment

k10

Parameters
D(mg) k12 (hr-1) k21 (hr-1) k10 (hr-1)
300 .3 .15 .2
k21 (hr-1)

Detailed conclusion

Drugs with larger k2 have lower peripheral/central distribution ratio. These drugs have faster distribution rate, faster elimination rate, and similar CLT.