One of the antibiotics which can tackle anthrax
Writing in the British Medical Journal, leading experts in infectious diseases say that Ciproxin may not remain as effective against anthrax if it is taken indiscriminately by the public at large.
Ciproxin is a "broad spectrum" antibiotic, meaning it is potentially effective against a wide range of bacteria.
The drug, says its makers Bayer, can work against food poisoning bugs such as E. coli and Pseudonomas aeruginosea, and many urinary tract infections.
Doctors are genuinely concerned that any public health scare which reduces their antibiotic firepower could have serious consequences for patients.
Professor Anthony Hart, a professor of medical microbiology at the University of Liverpool, told the Lancet that these were "important antimicrobials" and overuse could limit their usefulness.
"Antimicrobials need to be used according to national guidelines after appropriate assessment of risk - especially when such prolonged use is intended."
He added: "The important thing is that prophylactic treatment is only given to those who really need it, and to discourage its mass use by an understandably alarmed public.
Demand for doses
"Indiscriminate use of antibiotics can induce resistance in B anthracis and other organisms.
"To induce antimicrobial resistance on a mass scale would be an even greater triumph for the terrorists."
Doctors in the US, some of whom have been besieged by patients asking for "Cipro" prescriptions, are concerned about the drug being given inappropriately to children and pregnant women.
Professor Hart echoed this: "In children the main concern is damage to the cartilage in weight-bearing joints - seen when treating juvenile beagle dogs."
When bacteria become resistant to antibiotics, it means that higher doses are needed over a longer period to deal with the infection.
In the worst cases, bacteria can become completely resistant, meaning that the drug has little or no effect.
Bacteria get resistant because exposure to antibiotics means that tougher versions of the bugs - perhaps those which have a genetic mutation which helps pump the drug out of the bacteria cell - tend to prosper.