Pharmacy Times

HIV/AIDS Patients with Epilepsy: Evidence-Based Guidelines for AED Use

Author: Jeannette Y. Wick, RPh, MBA, FASCP

New guidelines offer detailed information on interactions between antiepileptic drugs and antiretroviral drugs.

HIV/AIDS patients often need to take antiepileptic drugs (AEDs). They may have long-standing epilepsy, develop reactive seizures due to opportunistic infections, or need treatment for symptomatic peripheral neuropathy.
However, extra care must be taken when mixing AEDs with HIV/AIDS medications. Enzyme-inducing AEDs (EI AEDs) such as phenytoin and carbamazepine are particularly problematic because of the high likelihood of significant interactions with antiretroviral (ARV) medications that can decrease both medications’ effectiveness.
To address this problem, a joint panel of the American Academy of Neurology and the International League Against Epilepsy has created the first evidence-based guidelines on AED use in patients with HIV. Based on a systematic review of evidence from 1950 through 2010, the panelists focused on protease inhibitors (PIs) and nonnucleoside reverse transcriptase inhibitors (NNRTIs) because they are metabolized by the P450 system. Their assumption was that significant interactions with this drug classes would increase risk for virologic failure and immunologic decline.
Their findings confirm that coadministration of EI AEDs with PIs and NNRTIs reduces their concentrations by 28% to 36%. Most of their recommendations are Level C, unless noted: As always, clinicians must consider each individual patient’s unique medication profile when making prescribing decisions and assessing drug interactions.

Ms. Wick is a visiting professor at the University of Connecticut School of Pharmacy and a freelance writer from Virginia.