Antivenin Drugs Help During Hurricanes

Monday, January 16th 2006, 9:43 am
By: News On 6

BRENTWOOD, Tenn. (AP) _ Jodie Richey was trying to escape Hurricane Rita when another disaster hit _ her 3-year-old daughter was bit by a rattlesnake in the family's yard. The little girl nearly died from the venom, which caused her leg to swell and turn black.

``It happened so quickly. As tiny as she is ... I was so scared,'' said Richey, who lives in Onalaska, Texas, which is near a large lake about 85 miles north of Houston.

Her daughter was saved by CroFab, a snake antivenin made by Protherics PLC, a British drug company that has recently become the main snakebite antidote manufacturer in the U.S.

Federal officials turned to Protherics for antivenin to treat the increase in snakebites that followed hurricanes Katrina and Rita when rain and floodwaters drove cottonmouths, copperheads and rattlesnakes from their natural habitats.

Protherics, whose U.S. headquarters are located in suburban Nashville, has also seen an increase in demand for CroFab as more people in fast-growing suburbs cross paths with snakes.

``To this point, we've been able to continue to meet a rising demand,'' Protherics' U.S. President Saul Komisar said. ``Every year, more is required, and we're planning for it. We're planning to make more for next year.''

Shortly after Katrina hit, Food and Drug Administration and other federal officials contacted Protherics to see if adequate supplies of its snake antivenin could be sent to the Gulf Coast.

``We anticipated that hundreds of people could be affected,'' said Jonathan Goldsmith, deputy director in the office of blood research and review for the FDA. ``We wanted to prepare for what we thought would be the worst-case scenario.''

Tom Arnold, medical director of the Louisiana Poison Control Center in Shreveport, La., said the worst-case scenario didn't happen, but there were still dozens more snakebites than usual.

It's difficult to determine an exact number, he said, because lines of communication were down after the storms and not all bites were reported.

``It's historically true that after any big storms come through, we always see more bites because of snakes being displaced, people going back in the clean-up phases and coming into contact with the snakes,'' Arnold said.

The number of bites by poisonous pit viper snakes _ a category that includes rattlesnakes, copperheads and cottonmouths _ has increased as the growth of the suburbs has collided with the snakes' habitats, according to Richard Dart, director of the Rocky Mountain Poison and Drug center in Denver.

``It's definitely true suburban areas are at greatest risk of snakebites,'' Dart said.

There were nearly 2,900 reports of pit viper bites in 2004 _ up by about 100 incidents over 2003, Dart said. That's a large increase over 2002 when there were only about 2,230 bites, and Dart estimates thousands of bites go unreported each year.

Around half a dozen people on average die from snakebites annually. People who own snakes or handle them usually are bit on the hand or arm while most other bites occur on the leg or foot.

Ray Latham was installing cabinets in a subdivision home under construction about 70 miles northeast of Los Angeles last spring when he walked out to his vehicle and found a Mojave Green rattlesnake in the street.

``I've never really been afraid of snakes,'' Latham said. ``So for some reason I didn't want to kill it. I was going to shoo it into the bushes, so I took a stick to pick it up and move it. When I lifted the stick, it bit my hand.''

Latham nearly died from the bite and was treated with CroFab at the Loma Linda University hospital, where he stayed for five days.

Sean Bush, a Loma Linda doctor and snakebite specialist who's a cast member of ``Venom ER'' on TV's Animal Planet channel, said suburban sprawl is a major reason why Southern California is a snakebite hotspot.

Florida, Arizona and Texas also see high numbers of venomous bites, he said.

Dart said 95 percent of the antivenin used in the U.S. in 2004 was CroFab, which became available on the commercial market in 2001 after Protherics won FDA approval to sell the drug.

Another antivenin made by Wyeth Pharmaceuticals _ which accounted for the remaining five percent of antivenin used in 2004 _ began to be sold in the 1950s though the company has since backed off on its production.

That news several years ago led to temporary shortages of snake antivenin in some regions because Protherics officials said they weren't prepared to supply the entire market.

Dart said there are no such shortages now of CroFab, which is made from the blood of Australian-raised sheep. CroFab is generally considered more effective than Wyeth's horse-based product, which can cause violent allergic reactions in some cases, he said.

CroFab's popularity has led to steady growth in sales, which were up 9 percent in U.S. dollar terms to $18.1 million for the six months ended Sept. 30, 2005.

Protherics _ a small company that employs about 200 people and began trading on the Nasdaq Stock Market in September _ makes other niche-oriented drugs. But CroFab is its biggest seller, accounting for about 60 percent of revenues last year, Komisar said.

``The future of this company is not on CroFab, although it's a critically important product,'' Komisar said. ``We'll be producing it for years to come. There are other products in our developmental pipeline, which in some ways will be much larger both in terms of revenues and impact on health care.''