Home Supplements That Start With K Kedrab: Rabies Immune Globulin Explained, Benefits, Administration Steps, and Side Effects

Kedrab: Rabies Immune Globulin Explained, Benefits, Administration Steps, and Side Effects

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Kedrab is a rabies immune globulin (human) given as part of emergency care after a bite or other exposure that could transmit rabies. Its role is immediate: it supplies ready-made antibodies at the wound site and in the bloodstream while the rabies vaccine trains your immune system to make its own defense. When used correctly—alongside thorough wound cleansing and a full vaccine series—Kedrab helps close the window of vulnerability in the first days after exposure. Clinicians value it because the dose is straightforward (20 IU/kg for all ages), it can be infiltrated around visible wounds, and any remaining amount is injected intramuscularly at a separate site from the vaccine. Though serious reactions are uncommon, it is a human-plasma–derived product and should be administered by trained professionals who can handle allergic events. This guide explains what Kedrab is, how it works, who needs it (and who does not), practical dosing steps with examples, common mistakes to avoid, and the most important safety notes so you can understand each part of post-exposure prophylaxis.

Essential Insights

  • Provides immediate antibodies at the wound and systemically to protect until vaccine immunity develops.
  • Standard single dose is 20 IU/kg (all ages), infiltrate wounds first; inject remainder intramuscularly at a distant site.
  • Do not give Kedrab to people previously vaccinated for rabies; it can blunt the booster response.
  • Typical local reactions are mild; severe allergy is rare but possible, especially in people with anti-IgA antibodies.
  • Avoid in the same syringe or site as rabies vaccine; keep biologics separate to prevent interference.

Table of Contents

What Kedrab is and when to use it

Kedrab is a U.S.-licensed human rabies immune globulin (HRIG). It is a sterile, ready-to-use solution of concentrated antibodies (primarily IgG) purified from human plasma with robust viral inactivation steps. Clinically, it’s used for post-exposure prophylaxis (PEP) after potential rabies exposure in people who have not completed a pre-exposure or prior post-exposure rabies vaccination series. The concept is simple: even after a high-risk bite, rabies can still be prevented if you act quickly, clean the wound thoroughly, and administer both HRIG and rabies vaccine correctly.

Who needs Kedrab?

  • Unvaccinated individuals with a bite or mucous-membrane exposure judged to pose a rabies risk—often from bats, dogs, raccoons, foxes, or other mammals that can carry the virus.
  • Those with uncertain vaccine histories or incomplete prior rabies vaccination. If there is no reliable documentation, plan PEP with HRIG while you clarify records.
  • People with significant wounds (especially deep punctures, lacerations, or multiple sites) where thorough wound infiltration with antibodies is feasible and beneficial.

Who typically does not need Kedrab?

  • Previously vaccinated people (documented pre-exposure series or prior full PEP). For them, the immune system mounts a rapid booster response to vaccine alone.
  • Individuals presenting very late after exposure, once the patient has already developed signs compatible with rabies (clinical disease), where HRIG and vaccine no longer alter the course.

Timing matters. HRIG is given once, ideally on day 0 (the same day vaccine is started). If it was missed, it can be administered up to day 7 of the vaccine series. After day 7, the body’s vaccine response is typically underway; adding HRIG later can theoretically reduce that active response.

Product features that help in practice

  • Kedrab’s potency is 150 IU/mL, supplied in 2 mL (300 IU) and 10 mL (1500 IU) single-dose vials.
  • It’s preservative-free and administered for wound infiltration first, with the remainder intramuscularly (IM) at a site distant from vaccine.

Kedrab is a supportive bridge—rapid passive immunity—while vaccine builds active, long-lasting protection across the first two weeks. Understanding when to use it and when not to is central to effective rabies prevention.

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How Kedrab works and why it matters

Rabies is almost uniformly fatal once symptomatic, but the virus has a vulnerable window: after entering tissue, it must replicate locally and ascend along peripheral nerves to the central nervous system. Kedrab exploits that window by placing neutralizing antibodies exactly where the virus entered—the wound—and throughout circulation. These antibodies bind rabies virions to prevent cell entry and local replication, buying the needed time for the rabies vaccine to generate an adaptive immune response.

Here’s the two-pronged logic:

  1. Immediate passive antibodies (Kedrab):
  • Delivered into and around the wound to maximize local neutralization.
  • Any remainder is given IM at a different site than vaccine to avoid interference.
  • Protection is temporary, waning over weeks.
  1. Durable active immunity (vaccine):
  • A four-dose series (days 0, 3, 7, 14) for most people; a fifth dose on day 28 for those who are immunocompromised.
  • Antibodies rise over 7–14 days, then maintain protective levels.

Why infiltration is emphasized: virus concentration is highest at the inoculation site. Direct infiltration saturates local tissue, where passive antibodies can neutralize viral particles before they enter nerves. This is why not infiltrating a visible wound is a known error—systemic IM dosing alone cannot reliably substitute for local antibody placement.

Dose discipline matters. HRIG is dosed at 20 IU/kg across all ages. Exceeding this can blunt the vaccine-induced response by overloading the system with passive antibodies that mop up vaccine antigens. Conversely, under-dosing or skipping infiltration leaves gaps in early protection.

Site separation prevents interference. The vaccine is administered in the deltoid (or anterolateral thigh for small children). HRIG is kept anatomically distant—and never in the same syringe or site—so the passive antibodies do not neutralize vaccine antigens locally.

Kedrab’s role is critical but time-limited. When combined with thorough wound cleansing and the complete vaccine schedule, it transforms a high-risk exposure into a preventable infection.

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Step-by-step PEP using Kedrab

A clean, repeatable workflow helps clinicians deliver effective PEP under pressure. Below is a practical, clinic-ready sequence for unvaccinated patients:

  1. Immediate wound care
  • Irrigate thoroughly with soap and water; consider a povidone-iodine solution if available.
  • Explore for depth and debris; debride devitalized tissue as indicated.
  • Assess tetanus status and the need for antibiotics based on wound characteristics and location.
  1. Risk assessment
  • Identify the species (bat, dog, cat, raccoon, fox, skunk, or other mammal), exposure type (bite, scratch, saliva to mucosa), and local rabies epidemiology.
  • Coordinate with public health if needed (e.g., pet observation, animal testing, regional advisories).
  1. Vaccination plan
  • Start rabies vaccine on day 0: 1.0 mL IM in the deltoid (anterolateral thigh for young children).
  • Schedule doses for days 3, 7, and 14 (plus day 28 if immunocompromised).
  • Do not inject vaccine in the gluteal area.
  1. Kedrab dosing and preparation
  • Calculate 20 IU/kg. Using the 150 IU/mL concentration, total volume is (20 × weight in kg) / 150 mL.
  • Do not exceed the calculated IU dose and do not repeat HRIG once vaccine is underway (after day 7, HRIG is generally not given).
  1. Infiltration first
  • Infiltrate as much of the dose as feasible into and around all identifiable wounds.
  • For multiple or large wounds where calculated volume is insufficient, dilute Kedrab with normal saline to expand volume for thorough infiltration.
  • Use judicious volumes in tight spaces (fingers, toes, ears, nose, lips) to minimize ischemia risk; distribute across entry points.
  1. IM remainder at a distant site
  • Inject any unused portion IM at a site distant from the vaccine (e.g., opposite thigh).
  • If the IM volume is large, split into multiple sites (e.g., >2 mL per site in small children; >5 mL per site in adults).
  1. Do not mix biologics
  • Never combine Kedrab and vaccine in the same syringe or anatomical site.
  1. Documentation and counseling
  • Record lot numbers, doses, and sites; provide a vaccine card and next-dose dates.
  • Counsel on expected local soreness, the importance of finishing all vaccine doses, and signs of allergic reactions (rare).
  • Remind patients that passively acquired antibodies may interfere with live vaccines (e.g., MMR and varicella) for several months; schedule those later per guideline intervals.
  1. Special scenarios
  • Unknown bite site (e.g., bat in the bedroom with possible unrecognized exposure): give the entire HRIG dose IM at a site distant from vaccine.
  • Late presentation: if vaccine has started without HRIG, it can still be given through day 7 of the series.

This sequence keeps care organized, minimizes common errors, and aligns bedside actions with best-practice recommendations.

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Dosing calculations and practical examples

Because Kedrab is standardized at 150 IU/mL, dosing is predictable across ages and body sizes. Use 20 IU/kg, infiltrate wounds first, and give the remainder IM at a separate site from vaccine. These examples demonstrate the math and real-world adjustments:

1) Toddler, 12 kg, single puncture wound to the calf

  • Dose: 20 × 12 = 240 IU total.
  • Volume: 240 ÷ 150 = 1.6 mL Kedrab.
  • Technique: Infiltrate the puncture tract circumferentially and into subcutaneous tissue at entry. If 1.6 mL is too much for the small wound, infiltrate what will fit comfortably (e.g., 0.6–1.0 mL) and inject the remainder IM (anterolateral thigh) on the opposite side of the vaccine.

2) Adult, 75 kg, multiple lacerations to forearm and hand

  • Dose: 20 × 75 = 1500 IU.
  • Volume: 1500 ÷ 150 = 10 mL (conveniently equals one 10 mL vial).
  • Technique: Systematically infiltrate along laceration margins and into wound beds. If 10 mL is inadequate to infiltrate all surfaces thoroughly (many small lacerations), dilute with normal saline (e.g., 1:1) to increase volume and coverage without exceeding IU dose. Any leftover after robust infiltration can be given IM in divided doses (e.g., vastus lateralis), away from the vaccine deltoid.

3) Child, 20 kg, dog bite to the face (lip and cheek)

  • Dose: 20 × 20 = 400 IU.
  • Volume: 400 ÷ 150 ≈ 2.7 mL.
  • Technique: Use low-pressure infiltration along margins to avoid tissue distortion that could complicate repair or healing. In cosmetically sensitive areas, prioritize meticulous infiltration to exposed tissues and consider modest dilution with normal saline for even distribution. Inject any remainder IM (anterolateral thigh), distant from vaccine.

4) Adult, 100 kg, bat exposure while sleeping; no evident wound

  • Dose: 20 × 100 = 2000 IU.
  • Volume: 2000 ÷ 150 ≈ 13.3 mL.
  • Technique: Because there is no identifiable wound, give all Kedrab IM in divided doses at sites distant from the vaccine (e.g., split between thighs). Do not use the gluteal area for vaccine, but IM Kedrab can be placed in large muscle groups as long as it’s anatomically far from the vaccine site.

Per-site volume tips

  • For IM injections, aim for ≤2 mL per site in small children and ≤5 mL per site in adults; split larger totals.
  • For tight anatomical spaces (fingers, toes, ear, nose, lip), infiltrate cautiously; use small aliquots and consider dilution to spread IU units across the whole wound without compromising perfusion.

Do not exceed 20 IU/kg. Larger IU doses can dampen vaccine response. Likewise, never repeat HRIG once vaccine has started unless specifically guided by public health for a documented administration error—and even then, dose limits apply.

These examples illustrate both the arithmetic and the art: precision in IU dosing and flexibility in how you distribute volume to cover real wounds safely.

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Mistakes to avoid and troubleshooting

Even experienced teams can slip into avoidable errors during urgent care. Here are the most common pitfalls and how to correct them:

1) Skipping wound infiltration

  • Problem: Giving Kedrab only IM misses the high viral load at the entry site.
  • Fix: If feasible, re-infiltrate directly into the wound as soon as practical, ensuring the total Kedrab dose administered doesn’t exceed 40 IU/kg across all doses combined. If re-infiltration is not possible, proceed with the vaccine schedule and monitor closely.

2) Co-administering in the same site or syringe as vaccine

  • Problem: Passive antibodies can neutralize the vaccine antigen locally.
  • Fix: Repeat the vaccine dose in a distant anatomic location as soon as the error is recognized. Seek guidance on whether additional HRIG is needed, being careful not to exceed total IU limits.

3) Under-dosing HRIG

  • Problem: Rounding down or using a single vial when more IU are required leaves gaps in early protection.
  • Fix: Recalculate precisely (20 IU/kg) and administer the missing IU as soon as possible (within day 7 of the series).

4) Over-dosing HRIG

  • Problem: Exceeding 20 IU/kg can blunt vaccine response.
  • Fix: Avoid this through double-checks. If excess was given, do not give more HRIG; complete the vaccine series and consider antibody titers if clinically indicated.

5) Injecting vaccine in the gluteal area

  • Problem: Reduced immunogenicity and sciatic nerve risk.
  • Fix: Repeat the vaccine dose correctly (deltoid in adults; anterolateral thigh in small children) and maintain proper spacing for remaining doses.

6) Not diluting for large or multiple wounds

  • Problem: Inadequate coverage of wound surfaces.
  • Fix: Dilute Kedrab with normal saline (Kedrab’s recommended diluent) to create enough volume to infiltrate every wound track without exceeding the IU dose.

7) Missing HRIG on day 0

  • Problem: Starting vaccine without HRIG in an unvaccinated patient.
  • Fix: Administer HRIG up to day 7 of the vaccine series. After day 7, skip HRIG and finish the vaccine series.

8) Stopping PEP due to mild side effects

  • Problem: Interrupting care can lead to failure.
  • Fix: Manage common reactions (e.g., soreness, low-grade fever) with analgesics or antihistamines and continue the schedule; consult public health for severe events.

By anticipating these issues and having clear corrective steps, teams can keep PEP on track and maintain the highest chance of success.

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Safety, side effects, and who should avoid

Overall safety profile
Kedrab is generally well tolerated. The most common effects are local pain and tenderness at injection sites and transient systemic symptoms such as headache or mild fever. Serious hypersensitivity reactions are rare but possible with any human immune globulin product, and facilities should be equipped to treat anaphylaxis (epinephrine, airway support).

Key warnings and precautions

  • Do not give Kedrab to previously vaccinated people. It can interfere with the anamnestic (booster) response to vaccine and offers no benefit in that context. Previously vaccinated patients receive vaccine only on days 0 and 3.
  • IgA deficiency risk: Individuals with anti-IgA antibodies may have a higher risk of severe hypersensitivity. This is not a universal contraindication, but it warrants careful risk–benefit discussion and readiness to manage reactions.
  • Live-virus vaccine interactions: Passively acquired antibodies from Kedrab can reduce the effectiveness of live attenuated vaccines (e.g., MMR and varicella). Defer those live vaccines for the recommended interval after HRIG and consult current guidance for exact timing.
  • Transmission risk: Kedrab is made from human plasma with multiple safeguards (donor screening and viral inactivation). The residual risk of transmissible agents is extremely low but theoretically present; counsel patients accordingly.

Who should avoid Kedrab

  • People who can document prior complete rabies vaccination (pre-exposure or prior full PEP).
  • Patients with a history of severe systemic reactions to human immunoglobulin products may still need PEP because of rabies’ lethality; in such cases, involve specialists early, prepare for emergency management, and consider the safest feasible approach to deliver protection.

Special populations

  • Pregnancy: Rabies exposure is a medical emergency. PEP, including HRIG, should not be withheld because of pregnancy.
  • Infants and children: Same dosing by weight (20 IU/kg) and full infiltration principles apply; use age-appropriate vaccine sites (anterolateral thigh in small children).
  • Immunocompromised patients: They should receive the five-dose vaccine series (days 0, 3, 7, 14, 28) after HRIG. Consider post-series antibody testing to confirm response.

Patient counseling essentials

  • Explain that HRIG is one-time and immediate, while the vaccine must be completed on schedule to build lasting protection.
  • Provide clear instructions on which arm or leg received vaccine versus HRIG so future doses remain anatomically distant from HRIG sites.
  • Encourage prompt return if there’s any sign of infection at the wound or allergic reaction.

In short, Kedrab’s risks are comparatively small next to the threat of rabies; careful screening and preparation make it safe for almost all who need it.

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Evidence, questions, and clinical context

Effectiveness within modern PEP
Since the adoption of cell-culture vaccines and standardized HRIG use, PEP failures in immunocompetent patients are extremely rare when protocols are followed. Kedrab has demonstrated non-inferior immunogenicity to comparator HRIG products in clinical studies, with the vast majority of recipients achieving rabies virus neutralizing antibody (RVNA) titers ≥0.5 IU/mL by day 14 when given with vaccine.

Concentration and dilution nuances
Kedrab’s 150 IU/mL potency aligns with most U.S. HRIG products, which simplifies training and dosing math. For extensive wounds where calculated volume is not enough for thorough infiltration, normal saline is the recommended diluent to expand volume without altering IU dose. This is a frequent practical question at the bedside and one of the most impactful pearls for correct administration.

Why never exceed 20 IU/kg?
PEP success depends on the vaccine-mediated response by week two. Over-dosing HRIG saturates antigens and can blunt the vaccine response, potentially lowering peak RVNA levels. Adhering to the 20 IU/kg ceiling, thorough wound infiltration, and the four-dose vaccine schedule (with the fifth dose for immunocompromised patients) keeps protection robust.

When the wound is tiny—or absent
For tiny distal wounds (e.g., fingertip puncture) you may not be able to place the full volume locally without risking tissue ischemia. Use small aliquots, do not force volume, and put the remainder IM. If there is no visible wound (bat exposure), give all HRIG IM in divided doses away from the vaccine.

Global context and product selection
Clinicians sometimes encounter patients who started PEP elsewhere. If they received a WHO-recognized regimen (including equine RIG in some regions), no further biologics may be needed once records are verified. If the regimen is incomplete or not recognized, local public health guidance and, in some cases, RVNA testing, inform catch-up plans.

Key takeaways for clinical reliability

  • Follow the sequence: clean, infiltrate HRIG, vaccinate on schedule.
  • Dose precisely: 20 IU/kg; infiltrate wounds first; remainder IM at a distant site.
  • Avoid interference: never share syringe or site with vaccine; respect live-vaccine timing later.
  • Prepare for rare reactions: screen for allergy risk, keep epinephrine ready, and don’t interrupt PEP for mild side effects.

The evidence and the logistics converge on the same theme: timely, correctly administered PEP prevents human rabies. Kedrab is a dependable HRIG option when applied with these principles.

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References

Disclaimer

This article is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment. Rabies exposures are medical emergencies. Always consult a qualified healthcare professional or public health authority for guidance specific to your situation, and follow local protocols and product labeling. If you think you have been exposed to rabies, seek urgent medical care.

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