Prior to initiating post exposure prophylaxis for a sexual assault victim, which lab tests should be sent on the patient?

• ELISA for HIV antibodies
  
• Creatinine (Tenofovir-emtricitabine [Truvada] can cause nephrotoxicity)
  
• LFTs (Zidovudine-lamivudine [Combivir] can cause abnormal LFTs, neutropenia, anemia)
  
• CBC w/ diff
  
• Anti-HBs antibodies
  
• HBsAg
• HCV antibodies
  
• screening, including rapid plasma reagin (RPR), for other sexually transmitted infections
  
• consider checking HIV viral load and HCV RNA if suspect that patient may have an acute HIV or Hep C infection

Source

Landovitz, R. and Currier. J. "Postexposure Prophylaxis for HIV Infection" New England Journal of Medicine. 29 Oct 2009.