title: Antiretroviral drugs for prevention of mother-to-child transmission: pharmacologic considerations for a public health approach.
abstract: OBJECTIVE
  Efavirenz-based antiretroviral therapy is recommended for prevention of mother-to-child transmission of HIV with two programmatic options: lifelong therapy for all women or treatment until cessation of breastfeeding. However, the risk of HIV resistance emerging after discontinuing efavirenz-based antiretroviral therapy is unclear. We review present knowledge surrounding the emergence of resistance after stopping efavirenz-based antiretroviral regimens.
  
  
  METHODS
  An expert review.
  
  
  METHODS
  A literature review was conducted to identify studies assessing risk for emergence of efavirenz-related resistance following discontinuation of efavirenz-based antiretroviral regimens containing either lamivudine and zidovudine or tenofovir disoproxil fumarate and lamivudine. Discontinuation strategies including the use of 'pharmacologic tails' are discussed in the light of what is known about the pharmacology of the drugs.
  
  
  RESULTS
  We found no head-to-head comparisons between zidovudine, lamivudine and efavirenz and tenofovir disoproxil fumarate, lamivudine and efavirenz. The risk for HIV resistance exists, even with a 5-7 day tail of zidovudine and lamivudine. For tenofovir disoproxil fumarate, lamivudine and efavirenz, we found no clinical data to inform a recommendation for a tail.
  
  
  CONCLUSIONS
  In order to prevent emergence of resistance, a tail of at least 2 weeks in duration may be required when discontinuing efavirenz in a regimen containing zidovudine and lamivudine. Studies are needed to characterize the risk of resistance among women who discontinue tenofovir disoproxil fumarate, lamivudine and efavirenz.
authors.affiliation: aInfectious Diseases Institute, Makerere University College of Health Sciences, Kampala, Uganda bNational Hemophilia Center, Tel Aviv, Israel cRadboud University Nijmegen Medical Centre, Nijmegen, The Netherlands dDepartment of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Lamorde
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Schapiro
authors.forename: David
authors.initials: D
authors.lastname: Burger
authors.forename: David J
authors.initials: DJ
authors.lastname: Back
mesh_terms: D000225:Adenine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D000328:Adult; D000480:Alkynes; D044966:Anti-Retroviral Agents / Q000008:administration & dosage* / Q000494:pharmacology; D048588:Benzoxazines / Q000008:administration & dosage / Q000494:pharmacology; D002648:Child; D003521:Cyclopropanes; D024882:Drug Resistance, Viral; D004358:Drug Therapy / Q000379:methods; D006678:HIV / Q000187:drug effects* / Q000302:isolation & purification; D015658:HIV Infections / Q000188:drug therapy* / Q000517:prevention & control / Q000635:transmission* / Q000821:virology; D006801:Humans; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D019259:Lamivudine / Q000008:administration & dosage / Q000494:pharmacology; D063065:Organophosphonates / Q000008:administration & dosage / Q000494:pharmacology; D011634:Public Health; D000068698:Tenofovir
chemical_list: D000480:Alkynes; D044966:Anti-Retroviral Agents; D048588:Benzoxazines; D003521:Cyclopropanes; D063065:Organophosphonates; D019259:Lamivudine; D000068698:Tenofovir; D000225:Adenine; C098320:efavirenz