Compare doses

Compare two doses over time

4× the dose → 2× the modeled exposure (less than proportional).

Under linear PK the exposure ratio would equal the dose ratio. The model produces 0.5× of that: describing the behavior for the values entered.

Concentration (mg/L)

Dose A (900 mg)Dose B (3600 mg)

Modeled estimate: Dose A peaks at 11.33 mg/L (AUC 405.8 mg·h/L); Dose B peaks at 22.66 mg/L (AUC 811.6 mg·h/L). Dose B's peak is 2× and its exposure 2× Dose A, less than proportional to the dose change. Full modeled values are in the metrics table below.

Drug PK profile

Saturable absorption (Emax/D50)

Maximum bioavailability Emax: 0.9
D₅₀ (half-saturation dose) (mg): 1800
Volume of distribution V (L): 60
Absorption rate ka (/h): 0.6
Elimination rate ke (/h): 0.115

Bioavailability vs dose

Bioavailability F falls as the dose rises: absorption is saturable, so exposure does not scale with dose.

Modeled PK metrics
	Dose A	Dose B	B / A
Peak (Cmax) mg/L	11.33	22.66	2.00×
Time to peak h	42.4	42.4	1.00×
Exposure (AUC) mg·h/L	405.8	811.6	2.00×
Time to steady state h	32.0	32.0	—

Educational PK model: not clinical guidance. Confirm any dose change with a prescriber or pharmacist.