Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

First Aid & Emergencies

Font Size

Snake Antivenom - Topic Overview

Snake venoms can cause many problems, such as:

Antivenom is a medicine that is given to stop snake venom from binding to tissues and causing serious blood, tissue, or nervous system problems. Side effects from antivenom can include rash, itching, wheezing, rapid heart rate, fever, and body aches.

Recommended Related to First Aid

Fishhook Injuries

Embedded in the person’s eye or face Deeply embedded in the skin

Read the Fishhook Injuries article > >

The use of antivenom depends on how much poison was injected (envenomation) and the type and size of the snake. Large snakes tend to inject more venom than smaller snakes do. Antivenom is used for mild, moderate, and severe envenomations.

  • Dry bites (no venom injected) do not need to be treated with antivenom.
  • Mild envenomation bites may cause mild symptoms, such as slight bleeding, pain, and swelling at the bite.
  • Moderate envenomations are more likely to cause symptoms of severe pain, swelling of the whole limb, and general feelings of illness, such as nausea, vomiting, and weakness.
  • Severe envenomation symptoms include severe pain, severe swelling, difficulty breathing, moderate to severe bleeding, and signs of shock.

For best results, antivenom should be given as soon as possible after the bite. It is usually given within the first 4 hours after the snakebite and may be effective for 2 weeks or more after the bite.

Serum sickness is a delayed reaction to receiving antivenom and can occur several days or weeks after treatment. Symptoms of serum sickness include fever, chills, rash, muscle aches, joint aches, itching, and blood in the urine. Call your doctor if you have received antivenom medicine and you now have symptoms of serum sickness.

    WebMD Medical Reference from Healthwise

    Last Updated: September 09, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
    Next Article:

    Today on WebMD

    Antibiotic on hand
    3d scan of fractured skull
    Father putting ointment on boy's face
    Person taking food from oven
    sniffling child
    wound care true or false
    caring for wounds
    Harvest mite

    Pollen counts, treatment tips, and more.

    It's nothing to sneeze at.

    Loading ...

    Sending your email...

    This feature is temporarily unavailable. Please try again later.


    Now check your email account on your mobile phone to download your new app.

    WebMD the app

    Get first aid information. Whenever. Wherever... with your iPhone, iPad or Android.

    Find Out More