Anthrax and Epilepsy

Anxiety about anthrax has been on everyone's mind lately. In reaction to the news reports, you might think your flu-like symptoms could be anthrax, and you might decide to take Cipro (ciproflaxin)—the antibiotic that has received the most publicity of late for its use against anthrax. Think again. Read the fine print of the news stories, and you will find a special warning against Cipro. Medical experts know that in certain individuals, Cipro increases the risk of developing seizures. "People most at risk for taking Cipro either have epilepsy or are already having seizures," explains Gregory L. Barkley, M.D., chair-elect of the Epilepsy Foundation's Professional Advisory Board. "Also, the medication can instigate seizures in individuals who have a strong family history of seizures, or carry certain risk factors for epilepsy, such as significant past head injuries."

To understand why Cipro increases the risk of seizures in people already susceptible to them, it helps to know what causes seizures in the first place. According to medical theory, a seizure develops when a chemical imbalance causes a "storm" of electrical activity in the brain. Either the brain contains too many chemicals that increase electrical activity (excitatory neurotransmitters) or not enough chemicals that cause nerve cells to stop firing (inhibitory neurotransmitters).

According to Barkley, Cipro blocks the receptor sites to which the inhibitory neurotransmitters would normally bind. The result? Too much excitability in certain portions of the brain, which may result in seizures.

If a person at high risk for developing seizures is exposed to anthrax and requires treatment with Cipro, the guidance of a physician is extremely important. "If it is necessary to use ciprofloxacin, patients should be closely monitored for seizures," says Patricia Osborne-Shafer, chair of the Epilepsy Foundation's Professional Advisory Board.

Fortunately, good news came a few weeks ago for those in whom the adverse effects of Cipro outweigh its benefits: alternatives do exist. The Food and Drug Administration (FDA) very recently approved doxycycline and penicillin G procaine for use in treating all forms of anthrax infections. Washington health officials even declared doxycycline the preventive drug of choice for individuals who may have been exposed to anthrax. Another benefit is the cost: "Older antibiotics such as penicillin and doxycycline are pennies a tablet. Cipro is several dollars a tablet," says Barkley.

What does this mean for people with epilepsy? "There is no significant increase in the risk of seizures with doxycycline, so it is a better drug to take for people at risk for seizures," says Barkley.

He does caution, however, that, for epilepsy patients taking older commonly prescribed barbiturates, including Dilantin (phenytoin) and Tegretol (carbamazepine), the half-life of doxycycline is significantly shorter. To maintain an adequate level of doxycycline in the blood of these patients, advises Barkley, it should be given twice daily.

Even with Cipro, however, the actual probability that it will cause seizures is low. "Maybe 1 in 1,000 individuals will experience an adverse reaction, but it is a potential risk that people should keep in mind," says Barkley. Additional factors may compound the risk of seizures when taking Cipro—factors like the consumption of caffeine and nonsteroidal pain relievers such as aspirin or aspirin-like products.

Although Cipro's link to seizures is cause for concern among the small percentage most likely to experience them, more far-reaching and potentially grave consequences associated with the haphazard use of Cipro loom large. "The indiscriminate use of ciprofloxacin by the public can lead to bacterial resistance when the drug is really needed," says Shafer.

A press release issued by the United States Department of Health and Human Services echoes Shafer's concern: "The agency is strongly recommending that physicians not prescribe Cipro for individual patients to have on hand for possible use against inhaled anthrax. In addition to the potential influence on supply of the drug, indiscriminate prescribing and widespread use of Cipro could hasten the development of drug-resistant organisms." It is concern about this threat—not the threat of developing anthrax—that public health officials hope to instill in the public.

"Like any potent medication, Cipro can do great good, and it can do serious harm, too," says Barkley.

Barkley predicts that the public's hysteria surrounding the threat of anthrax will not subside any time soon. In fact, he says, it may soon be on the upswing. "What I fear is that with the onset of the flu season, every person who gets sick with vague symptoms is going to be asking for antibiotics."

To keep the demand for Cipro in check, physicians will have a lot of patient education to do. Consumers determined to obtain Cipro will find ways to circumvent physicians. Nonetheless, physicians have a responsibility to prescribe judiciously, and to do what they can to quell the onslaught of needless requests for Cipro. Luckily, doxycycline and penicillin G procaine are now available and safe for people with epilepsy and others at risk for seizures. Physicians—not patients—write prescriptions. Tell your doctor about Cipro and epilepsy. If you have a bacterial infection and your doctor suggests Cipro, it is essential that you ask for a different medication.