Table 3.

Anticonvulsant drug interactions with DAAs

Drug (route of metabolism)	Known or potential interactions with DAAs	Comments
Lithium (renal)	No interaction expected based on known pharmacologic characteristics	Monitor and titrate dose according to clinical response and serum levels.
Valproic Acid, divalproex Parent: UGT (50%), minor CYP dependent oxidation pathway (<10%) Inhibitor of UGT,CYP2C9/19	No interaction expected based on known pharmacologic characteristics	Monitor and titrate dose according to clinical response and serum levels.
Carbamazepine Parent: CYP3A>> 2C8, 1A2 Inducer of CYP3A, 2C9, 2C19, UGT and possibly 1A2	Potential for ↓ DAAs concentrations	Carbamazepine is contraindicated with boceprevir [19] Co-administration of telaprevir with potent CYP3A4 inducers such as carbamazepine may lead to reduced DAA plasma concentrations and decreased efficacy [18] Carbamazepine clearance can also potentially be decreased [62]. Consider an alternate agent with non-inducing metabolic properties.
Oxcarbazepine Parent: UGT Inhibitor of CYPC19; Potent inducer of CYP3A4. Relative to carbamazepine, oxcarbazepine inducing effect is 54% lower [63]	Potential for ↓ DAAs concentrations	Co-administration of boceprevir and telaprevir with potent CYP3A4 inducers, may lead to reduced DAA plasma concentrations and decreased efficacy. Consider an alternate agent with non-inducing metabolic properties [64].
Lamotrigine (UGT)	No interaction expected based on known pharmacologic characteristics	Monitor and titrate dose according to clinical response.
Gabapentin (Renal)	No interaction expected based on known pharmacologic characteristics	Monitor and titrate dose according to clinical response.
Pregabalin (Renal)	No interaction expected based on known pharmacologic characteristics	Monitor and titrate dose according to clinical response.