Other antibiotics that appear to be effective in vitro include chloramphenicol and tetracycline. For theoretical reasons, infection would not be expected to respond to penicillins, cephalosporins, or aztreonam, although carbapenems like meropenem or imipenem may possibly work.
Infection caused by C. violaceum is rare, therefore there are no clinical trials evaluating different treatments. Antibiotics that have been used to successfully treat C. violaceum include pefloxacin, ciprofloxacin, amikacin, and co-trimoxazole.