Antivenin Shortage Rattles Hikers

At the dawn of a new snake season, hospitals are facing a temporary shortage of antivenin used to treat the swollen, blackened legs of hikers bitten by rattlers that have slithered out of their winter hibernation.

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.”

Fortunately for people, a new serum has just hit the market and can be procured within 24 hours, but is 60% more expensive. As of last week, only six hospitals around the state--but none in Los Angeles, Orange or Ventura counties--have 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, in the desert.

“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 farther 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, sometimes 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.

The Western rattlesnake--the most common in California--is found in woodlands, scrubby areas, desert or grasslands. The reptiles emerge from hibernation as the weather warms, usually in early spring--hence the term “snake season,” said Kent Beaman, herpetologist at the Natural History Museum of Los Angeles County.

Agoura Hills resident Joanne MacCallum stopped hiking during rattlesnake season six years ago, after she was bitten. Shopping at a plant nursery, a snake crawled out from under some vines and sank its fangs into her sandaled foot.

It felt as though she had stepped on a nail. Her foot and leg ballooned with fluid, not unlike a giant blister. By the time someone called 911, she said, her breathing was constricted and she had a strong metallic taste in her mouth.

Emergency room doctors treated her with the snake bite antidote antivenin.

“I was in intensive care for four days,” the interior decorator said. “Then I had an allergic reaction--hives--to the antidote.”

Medical literature and experts report a high incidence of allergic reactions to antivenin.

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.

New Serum Hits Market

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 having a lower incidence of allergic reaction and as a less costly treatment; in drug trials, researchers reported requiring 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 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 very 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.

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 entire 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 their own supplies were sufficient to treat at least one patient.

Dr. Wally Ghurabi, medical director at Santa Monica-UCLA, said “Early summer is when snake season really starts. I’d like to have a little more antivenin, but I think we’re OK.”

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

CroFab will cost about $15,000 for an average treatment, up from about $9,000 for a similar dose of antivenin. And because the typical victim is an uninsured, intoxicated man between the ages of 20 and 30, hospital officials and poison control experts said taxpayers are likely to end up footing the bill.

A Hiker Weighs the Risks

“Still, if it’s critical for saving lives, we’ll pay the difference,” said Rick Rowe, director of pharmaceuticals at Antelope Valley Hospital. “It would be nice to pay less but if it’s what [the company charges], we’ll pay it.”

For avid hikers and dog owners like Catherine Valeriote, this is somewhat reassuring.

“Out here in Calabasas my 3-year-old brought in a dead baby rattler from the backyard,” she said. “We know there are snakes and I’m willing to take a risk because I know there’s a remedy. But . . . if there’s nothing out there for my dogs, I’m really going to have to weigh the risks and probably do more walking in city streets.”

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