Jan. 20, 2000 (Boston) -- Doctors may soon be equipped with drugs to treat potentially fatal diarrhea that results from the most common infectious cause of diarrhea in kids in the U.S. Every year, severe diarrhea and vomiting caused by rotavirus kill an estimated 600,000 to 800,000 children.
Infection with rotavirus appears to stimulate nervous system cells that line the walls of the intestines, causing them to release large volumes of water and electrolytes, say Ove Lundgren, MD, PhD, and others from Göteborg University, University Hospital in Uppsala, and the Swedish Institute for Infectious Disease Control in Solna, all in Sweden.
Their findings, published in the Jan. 21 issue of the journal Science, suggest that it may be possible to reduce dehydration caused by rotavirus infections with drugs that slow the function of the nerves in the intestines. The welcome news comes just a few months after the FDA withdrew from the market a much-anticipated and highly promising vaccine against rotavirus infections. The withdrawal followed a series of reports, confirmed by the CDC in Atlanta, which showed that children who received the vaccine had a small but significant increase in risk for serious or even fatal bowel obstructions.
According to the CDC, most people with viral gastroenteritis (inflammation of the stomach and small and large intestines) recover completely without any long-term problems, provided that they replenish fluids lost through diarrhea and vomiting by taking extra fluids and special rehydration solutions (sold without prescription in drug stores). Infants, young children, the elderly, and people with immune systems weakened by disease or medications are especially at risk for dehydration, the CDC cautions.
The Swedish researchers had previously shown that gastroenteritis caused by infections with bacteria such as cholera causes the release of a naturally occurring chemical called serotonin that, in turn, causes nerve cells within the intestines to release large quantities of fluids, perhaps in an attempt to flush harmful substances out of the mucous layer lining the digestive tract.
In the current study, they saw the same thing occurring in the stomachs and intestines of newborn mice that had been exposed to the rotavirus. But when they gave one group of infected mice injections of lidocaine, a common anesthetic that deadens nerve impulses, they found that only six of the 14 mice developed diarrhea. In contrast, 14 of 15 mice that were infected with the virus but did not receive lidocaine went on to develop diarrhea. The researchers also found that three other drugs appeared to significantly reduce activation of the intestinal nervous system.
"On the whole, it's interesting to understand what type of substances are released on the epithelial cells [lining the stomach and intestines] to induce the activation of the nervous reflex, because that would be another point of attack for an anti-diarrheal drug," says Lundgren, professor of physiology at Göteborg University, in an interview with WebMD.
The study results suggest several possible targets for drugs aimed at preventing fluid loss from diarrhea. One strategy would be a drug that could block the corridors through which nervous system signals travel. Another approach might be to prevent or delay the release of serotonin or other chemicals that could stimulate the nervous system to release fluids, the authors say.
- Severe diarrhea and vomiting caused by rotavirus, a common viral infection, kills 600,000 to 800,000 children each year.
- In a new study on mice infected with rotavirus, the anesthetic lidocaine prevented the development of diarrhea.
- Researchers suspect that the drug deadens the nerve impulses that stimulate the intestines to release large quantities of fluid.