A comparison of erythromycin and cefadroxil in the prevention of flare-ups from asymptomatic teeth with pulpal necrosis and associated periapical pathosis.

In a previous study by our group with patients having asymptomatic teeth with pulpal necrosis and an associated periapical radiolucent lesion (PN/PL), it was shown that prophylactic administration of penicillin V or erythromycin (high-dose, 1-day regimen) resulted in a low incidence of flare-up (mean = 2.2%) and a low incidence of swelling and pain not associated with flare-up. No hypersensitivity responses occurred, and gastrointestinal side effects were found primarily with the erythromycins. To ascertain whether a single-dose administration of a long-acting 1-gm tablet of the cephalosporin antibiotic cefadroxil would result in a similar outcome, the present study was undertaken with 200 patients having quiescent PN/PL. The patients were randomly given either cefadroxil or erythromycin (base or stearate). Evaluations of flare-up were done 1 day, 1 week, and 2 months after endodontic treatment. A 2.0% flare-up incidence was found, with no statistically significant differences for cefadroxil (1.0%), stearate (2.0%), or base (4.0%). No hypersensitivity responses occurred. Gastrointestinal side effects were found primarily with the erythromycins (19.0%). The results showed that a 1-gm, single-dose regimen of cefadroxil was as effective as erythromycin and penicillin in preventing flare-ups and serious sequelae. A comparative analysis of the data from our first study (no peritreatment antibiotics) and the pooled data from our last three investigations (including the current trial) showed that peritreatment antibiotic coverage significantly reduced flare-ups and serious sequelae after endodontic treatment of asymptomatic PN/PL (p less than 0.001).