The process of absorbing, digesting, and excreting a medicine or food is called metabolism. The way the body metabolizes a particular medicine affects how often it must be taken. It also determines whether it will interact with other medicines or be affected by conditions such as liver disease.

Depakote ER tablets use special coatings to release medication over an extended period. After the outside film coating dissolves in the stomach, the outer layer of the tablet's contents begins to absorb fluid, forming a gel layer that releases the drug slowly.

The highest (peak) level of valproate in the blood is reached in 7 to 14 hours. The difference between the highest and lowest levels in the blood with the regular use of Depakote ER is 10% to 20% less than with regular Depakote. This may reduce side effects at the highest levels and improve seizure control when the levels are lowest.

If the same amount is taken, the body absorbs only about 89% as much medication from Depakote ER as from regular Depakote. This means that the once-daily dose of Depakote ER needs to be a little higher than the total daily doses of Depakote to achieve the same effect.

Depakote ER is broken down (digested) in the liver. People with liver disease should not take it. Other people need to be careful if they take other medicines that are digested in the liver, as many are. The metabolism of each medicine may be affected, changing how quickly it works and leaves the body.

This is why the doctor needs to know about everything that a person takes—prescription drugs, over-the-counter medications, vitamins and other dietary supplements, and herbs. In most cases, all the medicines can be used if the amounts are adjusted to allow for these changes.

When the amount of Depakote ER in the blood gets fairly high (but still in the usual range for effective treatment), the amount reaching the brain may go up a lot when just a little more is taken. This means that a small increase in the dose may have large effects on seizure control or side effects.