In a patient with diabetes mellitus, what can contribute to Dilantin toxicity?

Hypoalbuminemia is a significant factor that can contribute to Dilantin (phenytoin) toxicity due to its relationship with drug protein binding. Phenytoin is highly protein-bound; therefore, when albumin levels are low, there is an increased free fraction of the drug in circulation. This elevated free phenytoin concentration can lead to toxicity because only the unbound (free) drug is pharmacologically active and can cross biologic membranes.

In patients with diabetes mellitus, the state of hypoalbuminemia can arise from malnutrition, liver disease, or other comorbid conditions that are not uncommon in diabetic populations. Evaluating albumin levels is crucial as altered levels can significantly affect the dosing and management of phenytoin therapy.

Other factors, such as renal failure, can also influence phenytoin levels, but it mainly affects clearance rather than protein binding. Hyperlipidemia and increased blood glucose levels do not have the direct impact on phenytoin binding that hypoalbuminemia does. Hence, understanding the relationship between albumin levels and phenytoin binding is essential for managing potential toxicity in patients receiving this medication.