Drug General Information (ID: DDIZPXRA0V)
Drug Name			Phenobarbital		Drug Info		Methsuximide		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Anticonvulsants				Anticonvulsants
Structure

Mechanism of Phenobarbital-Methsuximide Interaction (Severity Level: Moderate)
Competitive inhibition of metabolic enzyme Click to Show/Hide Mechanism Graph
Drug Name		Phenobarbital				Methsuximide
Mechanism		Competition for the same metabolic pathway				Competition for the same metabolic pathway
Key Mechanism Factor 1
		Factor Name		Enzyme
		Factor Description		Alters the metabolism of the drug, leading to changes in the plasma concentration of the drug and affecting the pharmacological effects.
Mechanism Description		Increased plasma concentrations of Methsuximide and Phenobarbital due to competitive inhibition of the same metabolic pathway

Recommended Action
Management		If phenobarbital and a succinimide must be used together, monitoring of serum levels and observation for evidence of altered efficacy and safety is recommended. Dose adjustments may be necessary.

References
1	Giaccone M, Bartoli A, Gatti G, Marchiselli R, Pisani F, Latella MA, Perucca E "Effect of enzyme inducing anticonvulsants on ethosuximide pharmacokinetics in epileptic patients." Br J Clin Pharmacol 41 (1996): 575-9. [PMID: 8799524]
2	Rambeck B "Pharmacological interactions of mesuximide with phenobarbital and phenytoin in hospitalized epileptic patients." Epilepsia 20 (1979): 147-56. [PMID: 110583]