Although the antitoxin does not reverse existing symptoms, the deficits may stabilize and stop progressing [14] . Retrospective studies showed that early administration (within 24 h of symptom onset) reduced mortality and duration of hospital stay [88] . Animal studies suggest, if administered before clinical effects appear, the antitoxin might prevent symptoms from occurring [8] . The antitoxin is not generally recommended if a patient's exposure is greater than 72 h before administration [78] .