In the journal, “Neurology” articles published online before print (Neurology online before print, January 4, 2012 ),Doctors Birbeck and colleagues present an evidence-based guideline regarding antiepileptic drug selection for individuals with HIV/AIDS in terms of how to manage individuals who are taking antiseizure drugs, and are taking specific antiretroviral medication for their HIV/AIDS.  The investigators performed a literature review in order to assess what should be recommended with regards to potential interactions between antiseizure medications medications for HIV/AIDS known an antiretrovirals.  The researchers found that up to 55% of individuals taking antiretroviral medications may also be individuals taking antiepileptic drugs.  Specific recommendations included:

• Patients who take phenytoin may require an increase of the specific antiretroviral known as lopinavir/ritonavir dosages with an increase of about 50% to maintain a serum level.
• Patients who are taking valproic acid may require a zidovudine dosage reduction to maintain unchanged levels of zidovudine. 
• Taking valproic acid and efavirenz may not require any dosage adjustment. 
• Patients who take ritonavir may require a lamotrigine dose increase of almost 50% to maintain a serum level of lamotrigine.
• Coadministration of raltegravir and midazolam may not require any adjustment to the midazolam dosage.

  The general conclusion by the authors was that it may be important to avoid medications that are enzyme inducing in people who are on antiretroviral regimens that include certain classes of medications, such as protease inhibitors or nonnucleoside reverse transcriptase inhibitors, as many interactions can occur which may result in worsening of the disease.  If one needs to take these medications together in order to maintain seizure control patients may have to be monitored with more serum levels and dosage adjustments in order to make certain that appropriate levels are reached.