Which medication is known to increase the levels of Lamictal?

Valproic Acid is known to increase the levels of Lamictal (lamotrigine) due to its impact on the metabolism of this medication. Lamotrigine is primarily metabolized by the liver and is subject to glucuronidation. Valproic Acid inhibits the enzyme that is responsible for this glucuronidation process, leading to decreased metabolism and increased plasma concentrations of Lamictal. Higher levels of Lamictal can enhance its efficacy but also raise the risk of side effects, particularly in relation to its potential for causing skin rashes and Stevens-Johnson syndrome.

In contrast, Carbamazepine is an enzyme inducer that typically lowers Lamictal levels by speeding up its metabolism. Fluoxetine has a minimal effect in terms of altering Lamictal levels; while it may increase some medications' levels through its inhibitory effects, this is not the case with Lamictal. Oral contraceptives can sometimes affect the metabolism of various medications, but their influence on Lamictal does not lead to a significant increase in its levels. Thus, Valproic Acid stands out as the medication that notably increases Lamictal levels.