When should phenytoin be corrected for albumin?

When should phenytoin be corrected for albumin?

Corrects serum phenytoin level for renal failure and/or hypoalbuminemia. Use in patients with albumin ≤3.2 g/dL (32 g/L). The “Sheiner-Tozer Equation” is the official name of this correction.

How do you calculate corrected dilantin levels?

If clcr < 20 mL/min then Corrected Phenytoin = Total Phenytoin Level / ( (0.1 x albumin) + 0.1) This is so cool!

What is the normal corrected phenytoin level?

The reference range of free phenytoin is 1-2.5 µg/mL. In patients with renal failure associated with hypoalbuminemia, free phenytoin levels may be more accurate than total phenytoin levels.

How does albumin affect phenytoin levels?

Serum albumin concentrations < 3.5 g/dL have previously been shown to affect phenytoin binding ratios and to contribute to phenytoin intoxication. Decreased protein binding leads to an increase in the free fraction of the drug.

Does phenytoin bind to albumin?

Phenytoin is mainly bound to albumin, the percentage of bound drug being constant over a wide range of total drug concentrations.

When do you adjust phenytoin?

Maintenance Phenytoin Therapy Maintenance intravenous phenytoin therapy of 3-5mg/kg/day in three divided doses should be commenced 12 – 24 hours after loading dose. Doses should be adjusted gradually according to plasma-phenytoin concentrations.

How is a patient’s albumin level important to monitoring phenytoin therapy?

Phenytoin is highly protein bound and where protein binding is reduced, as in uraemia and hypoalbuminaemia, free phenytoin concentration levels will be increased accordingly. Therefore a patient with low albumin (<35g/L) may have a therapeutic level of free phenytoin but an overall low phenytoin level.

Is phenytoin bound to albumin?

Does phenytoin cause low albumin?

Phenytoin has a high protein binding (90%), so hypoalbuminemia condition will affect the free drug amount in the body, while it is known that only drug that unbound by protein (free drug) who can pass through the membrane and reach its target.

Is phenytoin highly protein bound?

Since phenytoin is highly protein-bound and free (unbound) phenytoin is the component producing the pharmacological effect, any factor which changes the protein binding of phenytoin would be expected to alter the free drug levels.

Does phenytoin bind to plasma protein?

The plasma protein binding of phenytoin was investigated in 100 epileptic patients, using equilibrium dialysis at 37 degrees C. The unbound fractions of phenytoin in plasma formed a skewed distribution, with a range of 9.7 to 24.7% and a median value of 12.3%.

What happens when Dilantin level is too high?

The neurotoxic effects are concentration dependent and can range from mild nystagmus to ataxia, slurred speech, vomiting, lethargy and eventually coma and death. Paradoxically, at very high concentrations, phenytoin can lead to seizures. Symptoms correlate well with the unbound plasma phenytoin concentration.

What is therapeutic DILANTIN level?

The therapeutic ranges for most adults have been established at 10.0-20.0 mcg/mL for total phenytoin (bound plus unbound) and 1.0-2.0 mcg/mL for free phenytoin (unbound only).

What is the antidote for DILANTIN?

There is no antidote, and there is no evidence that any method of gastrointestinal decontamination or enhanced elimination improves outcome. Activated charcoal should be considered if the patient presents early; however, the role of multiple-dose activated charcoal is controversial.

How long does it take for Dilantin levels to drop?

The plasma half-life in man after oral administration of phenytoin averages 22 hours, with a range of 7 to 42 hours. Steady-state therapeutic levels are achieved at least 7 to 10 days (5–7 half- lives) after initiation of therapy with recommended doses of 300 mg/day.

Can you take vitamin D with Dilantin?

The biggest thing to know, related to vitamin supplementation while taking this medications involves your vitamin D levels. Long term use of phenytoin (Dilantin) can deplete your vitamin D levels leading to the potential for other problems.

How do you adjust phenytoin?

A rough guide to making an adjustment to the daily dose that should increase a serum level without leading to supratherapeutic / toxic levels is: If the phenytoin concentration is < 7 mcg/mL, the dose may be increased by 100 mg/day. If the phenytoin concentration is 7-12 mcg/mL, the dose may be increased by 50 mg/day.

What is Dilantin 100 mg used for?

DILANTIN is a prescription medicine used to treat certain types of seizures called tonic-clonic (grand mal) and psychomotor (temporal lobe) seizures and to prevent and treat seizures that happen during or after brain surgery.