Bioavailability of cephalexin after intramuscular injection of its lysine salt

Pharmacokinetics of β-Lactam Antibiotics

“…As suggested earlier, cephalexin is well absorbed following a wide range (0.125-2.0 g) of oral doses administered as capsule, tablet, solution, or suspension (THORNHILL et al 1969;GOWER and DASH 1969;BERGAN et al 1970;GRIFFITH and BLACK 1971;O'CALLAGHAN et al 1971;LoDE et al 1979;BARRIOS et al 1975;Ac-TOR et al 1976a;PFEFFER et al 1977;HARTSTEIN et al 1977;HENNESS et al 1978;FINKELSTEIN et al 1978;CHOW et al 1979;BUSTRACK et al 1980;SIMON 1980 a;LE-CAILLON et al 1980;LODE et al 1980c). Peak serum concentrations of cephalexin occur within 1-2 h, dependent upon the formulation.…”

“…Serum levels appear to be dose proportional. BARRIOS et al (1975) have suggested that sodium cephalexin is not well absorbed after intramuscular injection, but it appears that intramuscularly administered sodium cephalexin is rate limited in its absorption when compared to oral doses. Urinary recovery, however, is independent of route of administration or dose.…”

“…Following a single intramuscular injection of cephalexin as the sodium or lysine salt, peak concentrations of cephalexin in serum occur in 30-60 min (REGAMEY et al 1974;GOWER et al 1973;BARRIOS et al 1975). The drug was recovered quantitatively in the urine within 24 h with 40% and 80% of dose appearing within 2 and 6 h respectively (REGAMEY et al 1974;GOWER et al 1973;BARRIOS et al 1975). Serum levels appear to be dose proportional.…”