Snakebite Antidote Runs Short

Hospitals and veterinarians are facing a temporary shortage of antivenin used to treat both people and pets bitten by rattlesnakes, triggering concern that supplies of the antidote will thin as summer approaches.

The nation’s longtime sole supplier of the antidote sent warnings to poison control centers around the country this week, saying it expects to be sold out until July.

A sister company that makes a similar product for the veterinary market also released a shortage announcement. Area veterinarians are scrambling to find antivenin for overly curious dogs and horses that get bitten by rattlesnakes. Some vets are even exploring foreign products.

“We’re in the same situation as the shortage for human antivenin,” said Debbie Houk, with an Irvine-based distribution company for animal medications.

“The company that supplies it to us is really rationing it out and anything they have will go to humans first. We haven’t been able to get it.”

Veterinarians like Beth Walter of Crown Valley Animal Care in Laguna Niguel saw the shortage coming and stocked up. “The humans get it before the animals. We’ve learned to anticipate this problem and buy extra before summer.”

Fortunately for people, a new serum is on the market and can be procured within 24 hours, but a standard treatment is 67% more expensive.

As of last week, only six hospitals around the state--but none in Los Angeles, Orange or Ventura counties--had ordered the new medicine.

Some 8,000 people in the United States are bitten by venomous snakes annually, according to the U.S. Food and Drug Administration. California Poison Control received 371 reports of snake bites last year. Area hospitals report a wide range of cases annually, from a half dozen at UCLA Medical Center to 50 at Antelope Valley Hospital in Lancaster.

“The shortage is not just a problem in Southern California. . . . It’s a nationwide problem,” said Dr. Rick Geller, medical director for California Poison Control. “There’s probably enough to get through the season, it’s just maldistributed. Nobody knows where all the antivenin is . . . [because] there’s no central registry.”

Generally, the further south a rattlesnake is found in California, the more potent its venom and the more serum is needed to treat a bite, experts say. To treat a single bite, a patient is likely to need 20 to 50 vials of the antidote.

About 130 different toxins are released during a bite, often causing excessive bleeding, cardiac problems and tissue and nerve damage. In extreme cases, an untreated bite could cause loss of a limb or death, experts say.

Targets Include Pets and Unwary Shoppers

Agoura Hills resident Joanne MacCallum was shopping at a plant nursery six years ago when a snake crawled out from under some vines and sank its fangs into her sandaled foot. She no longer hikes during rattlesnake season.

The bite felt as if she had stepped on a nail. Her foot and leg ballooned with fluid like a giant blister. By the time she told someone to call 911, her breathing was constricted and she had a “strong metallic taste” in her mouth, she said.

Animals such as dogs or horses that wander through the brush are easy targets for snakes.

“It’s more of a city problem when city development creeps into the hills and the snakes are in your backyard,” said Gina Drury, an employee at Ronald W. Caspers Wilderness Park outside San Juan Capistrano.

“If there is a shortage of the antivenin, we will be in big trouble,” said David Gordon, a Lake Forest veterinarian who has treated dogs that have been bitten on the face, neck, chest, leg and even the eye.

Antivenin Stopped But, New Serum Offered

Since 1954, Wyeth-Ayerst of Pennsylvania has manufactured Antivenin, a serum made from the blood of horses. In September, production was halted after the FDA found what the agency said were “quality control” problems.

In October, Protherics PLC received FDA approval for its sheep-derived serum, CroFab. The new product, which became available in December, is being touted as cheaper per treatment and with a lower occurrence of allergic reaction.

In drug trials, researchers reported using less CroFab per treatment than Wyeth’s antivenin. However, in actual cases, physicians reported needing to use more CroFab than in the trials, said Jude McNally, assistant director of Arizona Poison Control. Wyeth’s product costs about $469 per vial; CroFab is about $775. As many as 50 vials may be needed to treat humans and as few as five for a dog.

As of last week, Loma Linda University Medical Center, UC San Diego Medical Center, San Gorgonio Memorial Hospital in Banning, Palomar Medical Center in Escondido, Pomerado Hospital in Poway and Grossmont Hospital in La Mesa were the only California hospitals that have ordered the serum, according to Protherics PLC documents.

In the meantime, Wyeth said it expects to have a limited supply of its serum available in July “on an emergency basis only” and will stop production of Antivenin entirely by the end of the year. Doug Petkus, a spokesman for Wyeth-Ayerst, said the company’s decision was “based on a review of manufacturing capacity and human resource issues,” not economic concerns.

Hospitals May Run Low, but New Drug Is Ready A few hospitals around the state have reported an antivenin shortage. California Poison Control began alerting health care providers this week about the availability of the new CroFab serum.

To treat a snakebite victim last Sunday, UCLA Medical Center staff called the Los Angeles County Poison Control Hotline after exhausting the hospital’s 20-vial supply of Antivenin.

“They were out of supply on the old stuff and didn’t have the new stuff,” Geller said. “They were placing calls to other hospitals, scrambling around to meet the needs of one patient. If a place like UCLA doesn’t have it . . . that’s a problem.”

Eventually, UCLA located more antivenin.

Although many hospital officials contacted this week were unaware that Wyeth had no available serum, they said they had enough to treat at least one patient.

Protherics PLC has enough CroFab serum to distribute to hospitals within a day, said Dan McKerracher, spokesman for the British company.

CroFab will costs about $15,000 for an average treatment, up from about $9,000 for a similar dose of Antivenin.

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Staff writers Thuy-Doan Le, Tina Dirmann and Mai Tran contributed to this report.