What should be monitored in patients on Phenytoin with low albumin levels?

In patients receiving Phenytoin, particularly those with low albumin levels, it is crucial to monitor Phenytoin levels. Phenytoin is highly protein-bound, and low albumin means there is less protein available for the drug to bind to. This can lead to an increase in the free, unbound fraction of Phenytoin, potentially resulting in toxicity. Because the total serum Phenytoin level may appear normal even when the free levels are elevated in such patients, monitoring the drug levels more accurately reflects the patient's status regarding both efficacy and safety. This underscores the importance of regularly checking Phenytoin levels to ensure they remain within the therapeutic range, particularly when albumin levels fluctuate.