title: Penetration of erythromycin into periapical lesions after repeated doses of erythromycin acistrate and erythromycin stearate: a pilot study.
abstract: In 26 patients who had undergone apicectomy and extirpation of granulomas (n = 9) or radicular cysts (n = 17), concentrations of erythromycin, 2'-acetyl erythromycin, and their anhydro forms were determined with a novel chemical method in plasma and periapical lesions after at least 2 days of treatment with erythromycin acistrate (EA) (400 mg three times daily, n = 11) or erythromycin stearate (ES) (500 mg three times daily, n = 15). Oral surgery was performed 2 1/2 to 3 hours after the last dose. Blood samples were collected at the time of operation, and immediately before antibiotic treatment, and 1, 2, and 6 hours after treatment. At all time points EA produced at least twice the total antibiotic (2'-acetyl erythromycin plus erythromycin) concentrations in plasma as ES. Erythromycin levels in plasma were at least as high after EA treatment as after ES. In periapical lesions erythromycin concentration after EA was three times higher (1.34 +/- 0.28 micrograms/gm) than after ES treatment (0.40 +/- 0.17 micrograms/gm). Although the total drug concentration in periapical lesions was about the same after EA (2.64 micrograms/ml) and ES (3.41 micrograms/ml), most of the drug recovered after ES was antimicrobially inactive anhydroerythromycin (3.01 micrograms/gm). The concentration of anhydroerythromycin in plasma was approximately the same as that of erythromycin after ES throughout the dose interval. After EA treatment both plasma and the periapical lesion samples contained hardly detectable amounts of anhydroerythromycin. Hence EA has a good bioavailability essential for treatment and prophylaxis of bacterial infections in dentistry.
authors.affiliation: Department of Pharmacology and Toxicology, University of Helsinki, Finland.
authors.forename: R K
authors.initials: RK
authors.lastname: Tuominen
authors.forename: R
authors.initials: R
authors.lastname: Lehtinen
authors.forename: J
authors.initials: J
authors.lastname: Peltola
authors.forename: R
authors.initials: R
authors.lastname: Wikberg
authors.forename: A
authors.initials: A
authors.lastname: Gordin
authors.forename: P
authors.initials: P
authors.lastname: Kokkonen
authors.forename: P
authors.initials: P
authors.lastname: Pohto
mesh_terms: D000328:Adult; D000368:Aged; D001682:Biological Availability; D004917:Erythromycin / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use; D006801:Humans; D008875:Middle Aged; D010484:Periapical Granuloma / Q000601:surgery*; D010865:Pilot Projects; D011292:Premedication; D011355:Prodrugs; D011842:Radicular Cyst / Q000601:surgery*; D018805:Sepsis / Q000517:prevention & control
chemical_list: D011355:Prodrugs; D004917:Erythromycin; C056625:erythromycin 2'-acetate; C011462:erythromycin stearate