title: Plasma mepivacaine concentrations in patients undergoing third molar surgery.
abstract: Local anaesthetic-related systemic toxicity mainly results from elevated plasma concentrations of these drugs. We hypothesized that intraoral injection of submaximal doses of mepivacaine does not lead to toxic levels of this drug in blood. This study evaluated the plasma levels of mepivacaine in third molars surgeries.
  
  
  
  Twenty-one patients were randomly assigned into two groups: group I (two unilateral third molars; submaximal dose of mepivacaine 108 mg with epinephrine 54 μg) and group II (four third molars; submaximal dose of mepivacaine 216 mg with epinephrine 108 μg). Blood samples were collected before anaesthesia, and 5, 10, 15, 20, 30, 40, 60, 90 and 120 min after anaesthesia.
  
  
  
  Individual peak plasma concentrations ranged 0.77-8.31 μg/mL (group I) and from 2.36-7.72 μg/mL (group II). An increase in the average dose of mepivacaine from 1.88 ± 0.12 mg/kg (group I) to 3.35 ± 0.17 mg/kg (group II) increased the mean mepivacaine peak plasma levels from 2.33 ± 0.58 to 4.01 ± 0.69 μg/mL, respectively. Four patients obtained plasma levels of mepivacaine above the threshold for toxicity (5 μg/mL).
  
  
  
  Toxic levels of mepivacaine are possible, even when a submaximal dose is used. A twofold increase in the dose of mepivacaine caused the mean peak plasma concentration to increase proportionally, indicating that they may be predicted based on the relation of dose per bodyweight.
authors.affiliation: Division of Clinical Pharmacology, Department of Clinical Dentistry, Federal University of Ceará, Ceará, Brazil.
authors.forename: H C
authors.initials: HC
authors.lastname: Scarparo
authors.affiliation: Division of Oral and Maxillofacial Surgery, Oral and Maxillofacial Surgery Residency Program, Dr. José Frota Hospital Institute, Ceará, Brazil.
authors.forename: R N
authors.initials: RN
authors.lastname: Maia
authors.affiliation: Department of Pharmacy, Federal University of Ceará, Ceará, Brazil.
authors.forename: Ea Dos Santos
authors.initials: ED
authors.lastname: Filho
authors.affiliation: Division of Oral and Maxillofacial Surgery, Department of Clinical Dentistry, Federal University of Ceará, Ceará, Brazil.
authors.forename: Ecs
authors.initials: E
authors.lastname: Soares
authors.affiliation: Division of Oral Radiology, Department of Clinical Dentistry, Federal University of Ceará, Ceará, Brazil.
authors.forename: Fwg
authors.initials: F
authors.lastname: Costa
authors.affiliation: Division of Orthodontics and Pediatric Dentistry, Department of Clinical Dentistry, Federal University of Ceará, Ceará, Brazil.
authors.forename: Csr
authors.initials: C
authors.lastname: Fonteles
authors.affiliation: Division of Oral and Maxillofacial Surgery, Oral and Maxillofacial Surgery Residency Program, Walter Cantídio Universitary Hospital, Ceará, Brazil.
authors.forename: T P
authors.initials: TP
authors.lastname: Bezerra
authors.affiliation: Division of Orthodontics and Pediatric Dentistry, Department of Clinical Dentistry, Federal University of Ceará, Ceará, Brazil.
authors.forename: T R
authors.initials: TR
authors.lastname: Ribeiro
authors.affiliation: Department of Pharmacy, Federal University of Ceará, Ceará, Brazil.
authors.forename: N R
authors.initials: NR
authors.lastname: Romero
mesh_terms: D000293:Adolescent; D000328:Adult; D000766:Anesthesia, Dental; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007267:Injections; D008297:Male; D008619:Mepivacaine / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood; D008964:Molar, Third / Q000000981:diagnostic imaging / Q000601:surgery*; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local; D008619:Mepivacaine; D004837:Epinephrine
keywords: local anaesthetics; mepivacaine; oral surgery; plasma levels; third molars