Do you need antivenom after a copperhead snake bite? An NC doctor explains

North Carolina has a great many copperheads, and as a result, many copperhead bites. They vary in severity, but some require antivenom.

Copperheads are crotalids, or pit vipers. Other pit vipers include rattlesnakes and cottonmouths. Pit viper envenomations may need to be treated with antivenom, depending on the severity of the bite.

Copperhead bites can cause serious symptoms, including difficulty breathing. In severe cases, breathing can stop. Rapid heart rate, weak pulse and low blood pressure are also potential effects, according to North Carolina Blue Cross and Blue Shield.

WakeMed Emergency Physician Benjamin German said antivenom options have continued to improve.

“Essentially, antivenom is antibodies that are made to neutralize the different components of snake venom,” German said. “Antivenom has been around for over 100 years in various forms, and it’s gotten better with time.”

Antivenom doses: How much do you need?

A starting dose of the crotalid antivenom CroFab is 4-6 vials. More than that may be required, depending on the severity of the bite.

“Every bite is a little different, because we don’t know how much phenom the snake injects, because there’s so many variables there,” German said. “How much venom the snake has available, how much enters the tissue when it bites, the baseline health of the snake, or even the agitation level of the snake. In other words, if a snake is really irritated when it bites somebody, it can get more venom.”

Doctors follow a clinical protocol to determine how much antivenom is needed. More vials will be given if symptoms continue to worsen.

“You can’t give the dose and say, ‘okay, for this bite I’m only going to give four vials, and that’s going to be it,’ because we don’t know how much venom we’re trying to neutralize,” German said.

After antivenom is given, patients are monitored in the hospital.

“Typically, they get admitted to the hospital overnight because they’re probably going to need some pain medicine, they’re going to need that limb elevated, which helps with swelling, and it needs to be monitored,” German said. “There are cases where maybe four hours later it starts worsening again, maybe there was some venom stuck in the tissue that the antivenom couldn’t get to.”

Antivenom brands and how they work

There are two FDA approved crotalid antivenom options: CroFab and AnaVip.

CroFab is derived from sheep. It is the “only antivenom derived from native US pit vipers to treat envenomations from all species of North American pit vipers,” according to the CroFab website.

AnaVip is derived from horses, according to the AnaVip website.

“You take snake venom, you immunize the host animal with it — either sheep or horses — with small amounts over a period of time,” German said. “That host animal starts making large numbers of antibodies against the venom, then you draw out the animal’s blood and purify those antibodies.”

Some people have allergic reactions to crotalid antivenom. German said that newer antivenoms have less allergic reaction responses. But alpha-gal syndrome, a tick-born allergy to red meat, has been known to trigger allergic reactions to antivenom in patient.

“This applies for not just snake bites, but it’s very important to let your doctor know that you have alpha gal, because there may be an increased risk of allergic reaction with antivenom,” German said. The Charlotte Observer recently covered alpha-gal in North Carolina.

How much does antivenom cost?

The Charlotte Observer recently covered the cost of antivenom at North Carolina hospitals. Price per vial ranges from $9,000 to $14,000, but insurance nearly always covers antivenom and snake bite care.

Hospitals may offer financial assistance programs for those who are uninsured.

Eva Flowe

The Charlotte Observer

Eva Flowe is a North Carolina native and a graduate of the University of South Carolina. She joined the Charlotte Observer as part of the NC service journalism team in April 2026.