What is the first-line antibiotic for treating anthrax?

Ciprofloxacin is recognized as the first-line antibiotic for treating anthrax, particularly when inhalational anthrax is a concern. This fluoroquinolone antibiotic is effective against Bacillus anthracis, the bacterium that causes anthrax, and has a wide distribution in tissues and is capable of penetrating cell membranes, which may be necessary due to the intracellular nature of some of the anthrax bacteria.

In addition to ciprofloxacin, other antibiotics such as amoxicillin may also be effective against anthrax, especially in cases of cutaneous anthrax where the bacteria are less likely to spread. However, ciprofloxacin is preferred due to its proven efficacy in preventing and treating anthrax infections, particularly in serious cases involving inhalation where the risk of severe disease is much higher.

Tetracycline is another antibiotic that could be effective but is generally not the first choice due to considerations regarding dosing and its spectrum of activity. Vancomycin, while a critical drug for treating gram-positive bacterial infections, does not cover Bacillus anthracis effectively and is not indicated for anthrax treatment.