title: The impact of enzyme-inducing antiepileptic drugs on antiretroviral drug levels: a case-control study.
abstract: OBJECTIVE
  To evaluate the impact of enzyme-inducing antiepileptic drugs (EI-AEDs) on serum antiretroviral (ARV) levels in patients with HIV.
  
  
  METHODS
  Data from the U.S. Military HIV Natural History Study were screened to identify participants taking ARVs with EI-AEDs and controls taking ARVs with non enzyme-inducing AEDs (NEI-AEDs). The proportion of serum ARV levels below the recommended minimum concentrations (C(min)) was compared between these groups.
  
  
  RESULTS
  ARV levels were available for 10 individuals exposed to 16 intervals on combined ARVs/EI-AEDs (phenytoin and carbamazepine) and for 25 controls exposed to 30 overlap intervals on combined ARVs/NEI-AEDs. The percentage of overlap intervals with ≥1 ARV levels below C(min) was higher in the EI-AED group than in controls (37.5% vs. 23.3%; p=0.124). After excluding intervals associated with serum levels of EI-AEDs below the reference range (n=6), the proportion of intervals with ≥1 ARV level below C(min) was significantly greater among EI-AED recipients (60%) compared to controls (23.3%; p=0.008).
  
  
  CONCLUSIONS
  ARV levels below C(min) were more common in participants receiving EI-AEDs, the difference being statistically significant for intervals associated with EI-AED levels within the reference range. These data suggest that, in agreement with current guidelines, EI-AEDs should be avoided in patients receiving ARV therapy.
authors: Infectious Disease Clinical Research Program, Uniformed Services University of the Health Sciences, Bethesda, MD, USA. jason.okulicz@amedd.army.mil
authors: Jason F
authors: JF
authors: Okulicz
authors: Greg A
authors: GA
authors: Grandits
authors: Jacqueline A
authors: JA
authors: French
authors: Emilio
authors: E
authors: Perucca
authors: Jomy M
authors: JM
authors: George
authors: Michael L
authors: ML
authors: Landrum
authors: Edward P
authors: EP
authors: Acosta
authors: Gretchen L
authors: GL
authors: Birbeck
mesh_terms: D000328:Adult; D044966:Anti-Retroviral Agents / Q000097:blood* / Q000627:therapeutic use; D000927:Anticonvulsants / Q000097:blood* / Q000627:therapeutic use; D016022:Case-Control Studies; D004347:Drug Interactions / Q000502:physiology; D004790:Enzyme Induction / Q000187:drug effects / Q000502:physiology; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy / Q000201:enzymology*; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D044966:Anti-Retroviral Agents; D000927:Anticonvulsants