Chloramphenicol
Chloramphenicol is primarily bacteriostatic. It binds to the 50S subunit of the ribosome and inhibits bacterial protein synthesis. It has a wide spectrum of activity against gram-positive and gram-negative cocci and bacilli (including anaerobes), Rickettsia, Mycoplasma, and Chlamydia. Chloramphenicol is one of the drugs of choice for typhoid fever and other serious Salmonella infections; meningitis caused by susceptible Haemophilus influenzae, meningococci, or pneumococci when a -lactam antibiotic cannot be used; serious infection caused by B. fragilis; and rickettsial infection not responding to tetracycline or in which tetracycline cannot be used.
Chloramphenicol is effective in H. influenzae, meningococcal, and pneumococcal meningitis caused by susceptible organisms, but is relatively ineffective in meningitis caused by Escherichia coli and other Enterobacteriaceae.