How do anticonvulsants and protease inhibitors (PIs) interact?

Updated: Jan 15, 2019
  • Author: Jason F Okulicz, MD, FACP, FIDSA; Chief Editor: Michelle R Salvaggio, MD, FACP  more...
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Answer

Answer

In combination with RTV-boosted PIs (ATV/RTV, FPV/ RTV, LPV/ RTV, SQV/ RTV, TPV/ RTV), carbamazepine can decrease PI drug levels, which can result in antiretroviral treatment failure; carbamazepine levels may also be elevated; if coadministration cannot be avoided, close clinical monitoring is indicated; consider alternative therapy for carbamazepine.

Do not coadminister carbamazepine with unboosted ATV, once-daily LPV/r, or cobicistat-boosted PIs.

Carbamazepine in combination with DRV/RTV may decrease drug levels of DRV; DRV may increase carbamazepine drug levels; use caution if concomitant use cannot be avoided.

A combination of ATV or RTV with carbamazepine can lead to decreased PI drug concentrations; consider an alternative anticonvulsant.

LPV/RTV or ATV/RTV can decrease lamotrigine levels; lamotrigine dose increase may be required.

Phenobarbital decreases all PI drug levels; use alternative anticonvulsants, or monitor levels of both drugs.

Do not coadminister phenobarbital with LPV/RTV once daily, unboosted ATV, or unboosted FPV.

Phenytoin decreases levels of PIs; phenytoin levels may also be decreased, a dose increase may be needed when used with RTV.

Do not coadminister phenytoin with LPV/RTV once daily, unboosted ATV, or unboosted FPV.

LPV/RTV may decrease valproic acid (VPA) levels and increase LPV levels; monitor VPA levels; monitor virologic response and for LPV-related toxicities.


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