💊 Corrected Phenytoin (Albumin)
Adjust a total phenytoin level for hypoalbuminaemia with the Sheiner-Tozer equation.
Corrected Phenytoin (Albumin)
Measured total phenytoin (µg/mL)
Albumin (g/dL)
CrCl < 20 mL/min (or ESRD)
When to use
Interpret phenytoin concentrations when albumin is low.
How it works
Corrected = level / (0.2 × albumin + 0.1); use 0.1 instead of 0.2 if CrCl < 20 mL/min or ESRD. Therapeutic 10–20 µg/mL.
Key points
- Low albumin raises the free fraction at a given total level.
- A measured free phenytoin level is preferred when available.
- Especially important in renal failure.
References
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.