Acyclovir pharmacokinetics
How kidney function, dosing, and dialysis shape the concentration curves in AyFlux.
What does AyFlux show?
AyFlux lets you explore how dosing, kidney function, and dialysis affect predicted acyclovir concentrations over time. It uses a two-compartment pharmacokinetic model and also displays estimates for cerebrospinal fluid (CSF) and CMMG, an acyclovir metabolite.
The graphs show model predictions, not concentrations measured in a patient.
Why does kidney function matter?
Acyclovir is cleared mainly by the kidneys. When kidney clearance decreases, acyclovir can remain in the body longer. Dialysis can remove some of the drug, but the effect depends on the treatment method and schedule.
Try comparing the same dose with different kidney function or dialysis settings. Watching the curves change is more useful than focusing on a single predicted concentration.
Where does valacyclovir fit in?
Valacyclovir is an oral prodrug that the body converts to acyclovir. AyFlux includes an oral valacyclovir mode so you can explore how absorption and conversion assumptions change the predicted acyclovir curve.
Reading the charts
- Plasma acyclovir: predicted drug concentration in the blood over time.
- CSF acyclovir: an estimate of drug exposure in cerebrospinal fluid, not a measured CSF level.
- CMMG: predicted metabolite concentrations, which cannot diagnose neurotoxicity.
- Uncertainty bands: a range of results from the model's assumptions, not a guarantee for an individual patient.
Explore more
Selected references
The simulator includes a more complete reference list. To start, see published research on acyclovir kinetics in end-stage renal disease and CMMG and neurological symptoms.