Pharmacokinetics of loracarbef and interaction with acetylcysteine.

A study was conducted to evaluate the pharmacokinetics of loracarbef, a new synthetic oral carbacephem antibiotic, following administration of 400 mg in normal male volunteers. The influence of food and possible interaction with acetylcysteine, a commonly used mucolytic agent, was also studied. Twelve healthy volunteers participated in the study and randomly received an oral dose of 400 mg loracarbef in the fasting state, 400 mg loracarbef following a standard breakfast or 400 mg loracarbef together with 200 mg acetylcysteine in granular form. Serum and urine concentrations were determined over 24 h by means of a bioassay. Loracarbef was well tolerated. Four volunteers complained of mild, transient headache. The substance was well absorbed with a mean peak level of 19.21 +/- 3.94 mg/l in the fasting state; it was primarily excreted in active form via the kidneys (urine recovery/24 h: 86-92%). The elimination half-life ranged from 70.3 to 102.0 min. Acetylcysteine had no effect on the absorption of loracarbef. The intake together with food delayed the absorption time, but had no influence on the bioavailability.