Bioavailability and pain study of cefamandole nafate

The bioavailability of parental cefamandole, nafate, a new cephalosporin antibiotic, was evaluated with respect to the effects of a lidocaine diluent on its tolerability and absorption after intramuscular administration. Twelve adult male volunteers were injected with 1 Gm of cefamandole nafate in a three-way randomized, crossover study using the intravenous or the intramuscular route with cefamandole nafate in saline or in 1% lidocaine. The intramuscular injections were double blinded. Mean serum concentrations and cumulative urine outputs of cefamandole nafate were not significantly different (P > 0.05) following intramuscular administration using either the saline or lidocaine diluents. Furthermore, there was no significant difference in the areas under the serum concentration-time curve (AUC). The degree of pain experienced by subjects receiving intramuscular cefamandole nafate was evaluated during 1 hour after injection using a numerical scoring system. Lidocaine diluent significantly reduced the incidence and duration of pain after cefamandole nafate injection, and this form of administration was well accepted by the subjects in the study.