What medication is recommended for a patient suspected of having rabies or at risk of developing it?

Rabies Post-Exposure Prophylaxis

For patients suspected of rabies exposure or at risk of developing rabies, immediately administer both rabies vaccine (5 doses on days 0,3,7,14, and 28) and human rabies immune globulin (HRIG) at 20 IU/kg body weight, with as much HRIG as anatomically feasible infiltrated directly into and around the wound site. 1, 2, 3

Critical First Steps

Wound Management

• Thoroughly cleanse all wounds with soap and water for at least 15 minutes immediately after exposure - this single intervention can markedly reduce the likelihood of rabies transmission even before any biologics are administered 2, 4

Immediate Passive and Active Immunization

For Previously Unvaccinated Persons:

• Administer HRIG at 20 IU/kg body weight on day 0 - infiltrate the full dose thoroughly into and around the wound site if anatomically feasible, with any remaining volume injected intramuscularly at a site distant from vaccine administration 1, 2, 3
• Never administer HRIG in the same syringe or anatomical site as the vaccine 1
• If HRIG was not given on day 0, it can still be administered through day 7 of the vaccine series - beyond day 7, HRIG is not indicated as antibody response to vaccine is presumed to have occurred 1, 3

Rabies Vaccine Schedule:

• Administer 1.0 mL intramuscularly in the deltoid area (never gluteal) on days 0,3,7,14, and 28 1, 2
• For children, the anterolateral thigh is also acceptable 1
• The gluteal area must never be used as it results in lower neutralizing antibody titers 1

For Previously Vaccinated Persons:

• Administer only 2 doses of vaccine (1.0 mL each) on days 0 and 3 1, 2
• Do not administer HRIG - it is unnecessary and may interfere with the anamnestic antibody response 1, 2
• Previously vaccinated persons are those who completed a recommended pre-exposure or post-exposure regimen with cell culture vaccine and had documented rabies virus neutralizing antibody 3

Special Populations

Immunosuppressed Patients

• Use the full 5-dose vaccine regimen (days 0,3,7,14, and 28) even if previously vaccinated, as the immune response may be inadequate 1
• Do not withhold or delay immunosuppressive medications during post-exposure prophylaxis unless they can be safely discontinued 1
• Obtain serum samples for rabies virus neutralizing antibody testing after completing the series to ensure adequate response 1
• If no acceptable antibody response is detected, manage in consultation with public health officials 1

Pregnant Patients

• Pregnancy is not a contraindication to post-exposure prophylaxis - the potential consequences of inadequately managed rabies exposure far outweigh any theoretical risks 1
• Studies show no increased incidence of abortion, premature births, or fetal abnormalities with rabies vaccination 1
• Rabies exposure should never be regarded as a reason to terminate pregnancy 1

Patients with Vaccine Allergies

• Persons with serious hypersensitivity to vaccine components should be revaccinated with extreme caution 1
• Antihistamines may be given prophylactically, and epinephrine must be immediately available 1
• Once initiated, prophylaxis should not be interrupted due to local or mild systemic reactions - these can be managed with anti-inflammatory and antipyretic agents 1

Common Pitfalls to Avoid

• Never delay post-exposure prophylaxis, especially with severe wounds to the face, neck, and head where the incubation period may be as short as 10 days 2, 3
• Do not underestimate bat exposures - bat bites may be minor and undetected, and post-exposure treatment should be considered for any physical contact with bats when bite or mucous membrane contact cannot be excluded 3
• Never administer more than the recommended 20 IU/kg dose of HRIG as it can partially suppress active antibody production 1
• Do not fail to infiltrate HRIG directly into wound sites - rare prophylaxis failures have been reported when smaller amounts were infiltrated at exposure sites 1

Clinical Rabies: No Effective Treatment

Once clinical symptoms develop, rabies is essentially 100% fatal and no proven effective medical treatment exists. 1, 5

• Only 6 documented human survivors exist worldwide, and 5 of these had received vaccination before symptom onset 1, 5
• Initiating rabies vaccination after onset of clinical symptoms is not recommended and may be detrimental 1
• When definitive diagnosis is obtained, focus on comfort care and adequate sedation, as patients become extremely agitated with stimuli such as loud noises, air currents, and running water 1, 5
• Death typically occurs within 7 days of symptom onset 5

Available Products in the United States

Rabies Vaccines:

• Imovax® Rabies (human diploid cell vaccine - HDCV) 1
• RabAvert® (purified chick embryo cell vaccine - PCEC) 1

Rabies Immune Globulin:

• Imogam® Rabies-HT (human rabies immune globulin) 1, 3

Patient assistance programs are available for uninsured or underinsured patients through both manufacturers. 1