The US Food and Drug Administration (FDA) approved Friday the use of the antibiotic,(generic: levofloxacin), to treat patients with the deadly pneumonic plague in the event of a bioterror event.
Levaquin is already approved for the treatment of a wide array of infections to include urinary tract infections, respiratory and sinus infections and skin infections. In addition, the fluoroquinolone antibiotic is already approved as a prophylactic measure in the event of a anthrax bioterror event.
The regulatory agency approved the antibiotic using a rarely used animal rule called the Animal Efficacy Rule.
According to an FDA statement:
The animal efficacy rule allows evidence to support a drug's approval to be based entirely on animal studies to provide a regulatory pathway in instances where it is not feasible or ethical to conduct trials in humans. Plague is a rare disease, with only 1,000 and 2,000 cases a year around the world, and hence would not be possible to conduct adequate efficacy trials in humans.
Levaquin’s approval was based on an efficacy study conducted in African green monkeys that were infected with the plague bacterium in a laboratory setting. The study found 94 percent of the monkeys given Levaquin survived.
The plague is caused by the bacterium, Yersinia pestis. There are three forms of human plague: bubonic (affecting the lymph nodes), pneumonic (lungs) and septicemic (blood stream).
Pneumonic plague is probably the most serious form of plague. Here the bacteria infect the lungs and cause pneumonia. It is contracted when the bacteria is inhaled (primary) or develops when bubonic or septicemic plague spreads to the lungs.is a rare form of plague accounting for about 1% of all plagues.
Primary plague pneumonia has a short incubation period of 1-3 days, after which there is sudden onset of flu-like symptoms including fever, chills, headache, generalized body pains, weakness, and chest discomfort.
A cough develops with sputum production, which may be bloody, and increasing chest pain and difficulty in breathing. As the disease progresses, hypoxia (low oxygen concentration in the blood) and hemoptysis (coughing up blood) are prominent. The disease is invariably fatal unless antimicrobial therapy commences within 24 hours of exposure.
Pneumonic plague is contagious and can be transmitted person to person. People with primary pneumonic plague generate large quantities of infectious aerosols that pose a significant risk to close contacts. It is highly communicable under appropriate climate conditions, overcrowding and cool temperatures.
Fleas typically serve as the vector of plague.have been linked to the domestic cats and dogs that brought infected fleas into the house.
According to the CDC, Streptomycin, gentamicin, the tetracyclines, and chloramphenicol are all effective against pneumonic plague.Levaquin is produced by Janssen Pharmaceuticals, a unit of Johnson & Johnson.