Previous studies have shown that drugs with a mode of action to enhance glutamate clearance might be effective in the treatment of chronic pain. In animals, repeated does of the antibiotic ceftriaxone have reduced both visceral and neuropathic pain. The drug induces activation of the GLT-1 gene. This is the first study to explore the analgesic activity of ceftriaxone in humans.

Researchers at University Sapienza in Rome analyzed whether a single dose of ceftriaxone given for antimicrobial prophylaxis prior to surgery could enhance patient pain thresholds after surgery. Forty-five patients undergoing surgery for carpal tunnel syndrome or ulner nerve compression disease participated in the study. They were randomized in three treatment groups: IV doses of saline, saline with ceftriaxone and saline with cefazolin. Injections were administered one hour prior to surgery, and mechanical pain thresholds were measured 10 minutes before the injections and 4 to 6 hours following surgery. No analgesic drugs were allowed in the first six hours after surgery.

Results in the human subjects showed that those treated with saline and cefazolin showed no change in mechanical pain thresholds six to seven hours after surgery, but pain thresholds in patients given a single preoperative does of ceftriaxone increased significantly.

This is the first study showing analgesia resulted from administration of an antibiotic in humans. The authors concluded that ceftriaxone should be the drug of choice for surgical prophylaxis in situations when pain does not rapidly resolve following surgery or when strong pain is expected to occur after surgery.'