Infectious Diseases: Trying Too Hard For the Fast Knockout

Many cases of meningitis are caused by viruses, but by far the most deadly is the bacterial form. The disease, which causes inflammation of the membranes covering the brain and spinal cord, often strikes without warning and can kill a husky young man within hours. Fatal in at least 10% of cases, it understandably causes public panic when it breaks out. Yet, little is known about it or about the best way to treat it. In fact, careful studies have only served to deepen some of its mysteries. But, as the University of Southern California's Dr. Paul F. Wehrle told the New York Academy of Sciences, there is at least one new lesson in treating meningitis that doctors could well learn.

Several antibiotics are effective against the infection, and because the disease is so severe, doctors have been inclined to combine them, hoping for a fast knockout. As Dr. Wehrle puts it, "There is a fixed and mystical belief that if one antibiotic is good, two must be better, and three even more efficacious." Not so, the Wehrle team found. In a twelve-month study at Los Angeles County General Hospital, every meningitis patient got intravenous ampicillin, a fast-acting form of penicillin, while alternate patients received, in addition, chloramphenicol and streptomycin. There were five deaths among 129 patients on ampicillin alone, but 13 among the 111 who got all three drugs. Using an antibiotic combination is evidently detrimental, perhaps because it interferes with the action of ampicillin.