Prophylaxis postexposure

Animal studies and human case reports have led to several proposed postexposure prophylactic regimens for asymptomatic patients exposed to pulmonary agents, specifically phosgene, to prevent development of complications. Unfortunately, all of these treatments lack evidence in systemic studies, and asymptomatic patients may find at least one of the treatments unacceptable  

---

Individuals in contact with people infected with acute HAV, including household and sexual partners, staff and children from day care facilities, and food handlers of restaurant establishments may be candidates for postexposure prophylaxis. 

Postexposure prophylaxis for perinatal exposure depends upon the mother s HBsAg status.24 Mothers who are HBsAg-positive should have their newborns immunized with both the hepatitis B vaccine and HBIG 0.5 mL. This regimen is 85% effective in preventing the hepatitis B carrier status if administered... 

IG is used when pre- or postexposure prophylaxis against HAV infection is needed. It is most effective if given during the incubation phase of infection. A single dose of IG of 0.02 mL/kg intramuscularly is recom-... 

HBIg is used only for postexposure prophylaxis for HBV for perinatal exposure of infants of HBV-carrier mothers, sexual exposure to HBsAg-... 

If a patient has been exposed to rabies, the treatment objectives consist of thorough irrigation of the wound, tetanus prophylaxis, antibiotic prophylaxis (if indicated), and immunization. Postexposure prophylaxis immunization consists of both passive antibody administration and vaccine administration. 

Stavudine (d4T, Zerit) is a thymidine nucleoside analogue that is active against HIV-1 and HIV-2. It is approved for the therapy of HIV infection as part of a multidrug regimen and is also used for postexposure prophylaxis. 

Lamivudine (3TC, Epivir) is a cytosine nucleoside analogue with activity against HIV-1, HIV-2, and hepatitis B virus. It is approved as part of a multidrug regimen for the therapy of HIV infection in adults and children and has been used for HIV postexposure prophylaxis. Combination products contain lamivudine with either zidovudine (Combivir) or zidovudine and abacavir (Trizivir). The use of low-dose lamivudine in the treatment of chronic hepatitis B is described in Chapter 50. 

Efavirenz (Sustiva) is approved for the therapy of HIV infection of adults and children and is also used for postexposure prophylaxis. It is the only NNRTI approved for once-daUy dosing. Rash, although rarely severe, is a common adverse effect of efavirenz. Elevated liver enzymes and serum cholesterol also may occur. Central nervous system (CNS) effects in approximately half of patients may include dizziness, headache, insomnia, drowsiness, euphoria, agitation, impaired cognition, nightmares, vivid dreams, and hallucinations. These effects often subside after several weeks to months of therapy. 

Treatment involves the application of rabies-specific antibodies that are infiltrated around the bite wound, in addition to immunization. The antibodies provide passive protection and are able to neutralize the virus. For developing countries, these antibodies are both too expensive and difficult to produce in large quantities. In addition to this, there is a dramatic shortage of rabies monoclonal antibodies (MAbs) available on a worldwide basis. The production of inexpensive and safe plant-derived MAbs would be useful in postexposure prophylaxis-global health benefit. 

Tetanus immune Postexposure prophylaxis 250 units IM. Tetanus... 

Postexposure Five-doses at days 0, 3, 7, 14, and 28 2. Postexposure prophylaxis (administer with rabies immune globulin)... 

Postexposure prophylaxis if > 5 years has passed since last dose... 

Hepatitis Hepatitis immune globulin (HBIG) 0.06 mL/kg IM as soon as possible after exposure up to 1 week for percutaneous exposure or 2 weeks for sexual exposure. 0.5 mL IM within 12 hours after birth for perinatal exposure. Postexposure prophylaxis in nonimmune persons following percutaneous, mucosal, sexual, or perinatal exposure. Hepatitis vaccine should also be administered. 

Measles Immune globulin (IM) Normal hosts 0.25 mL/kg IM. Postexposure prophylaxis (within 6 days after exposure) in nonimmune contacts of acute cases. 

Tetanus Tetanus immune globulin Postexposure prophylaxis 250 units IM. For severe wounds or when there has been a delay in administration, 500 units is recommended. Treatment of tetanus and postexposure prophylaxis of nonclean, nonminor wounds in inadequately immunized persons (less than two doses of tetanus toxoid or less than three doses if wound is more than 24 hours old). 

Varicella Varicella-zoster immune globulin Weight (kg) Dose (units) Postexposure prophylaxis (preferably within 48 hours but no later than within 96 hours after... 

Other potential uses of cidofovir that are currently under investigation include treatment of the polyomavirus-associated progressive multifocal leukoencephalopathy syndrome in patients with AIDS, postexposure prophylaxis against smallpox, and topical treatment of molluscum contagiosum. Topical cidofovir is not currently available in a standardized preparation. 

Both amantadine and rimantadine, in doses of 100 mg twice daily or 200 mg once daily, are approximately 70-90% protective in the prevention of clinical illness by influenza A. The effectiveness of postexposure prophylaxis is inconsistent. When begun within 1-2 days after the onset of clinical symptoms of influenza, both drugs reduce the duration of fever and systemic complaints by 1-2 days. 

Varicella Varicella-zoster immune globulin Weight (kg) Dose (units) M0 125 IM 10.1- 20 250 IM 20.1- 30 375 IM 30.1- 40 500 IM > 40 625 IM Postexposure prophylaxis (preferably within 48 hours but no later than within 96 hours after exposure) in susceptible immunocomprised hosts, selected pregnant women, and perinatally exposed newborns. 

---