Accession Number : ADP008849

Title :   Methemoglobin and Sulfhemoglobin Formation Due to Benzocaine and Lidocaine in Macaques.

Corporate Author : ARMY MEDICAL RESEARCH INST OF CHEMICAL DEFENSE ABERDEEN PROVING GROUND MD

Personal Author(s) : Martin, Dale G. ; Woodard, Claude L., JR. ; Gold, Mark B. ; Watson, Charles E. ; Baskin, Steven I.

Report Date : 13 MAY 1993

Pagination or Media Count : 11

Abstract : Benzocaine (BNZ) and lidocaine (LC) are commonly used topical (spray) anesthetics approved for use in humans. BNZ has structural similarities to methemoglobin (MHb) forming drugs that are current candidates for cyanide prophylaxis, while LC has been reported to increase MHb in man. We therefore, compared MHb and sulfhemoglobin (SHb) production in three groups of Macaques (Macaca mulata, Chinese rhesus and Indian rhesus, and Macaca nemistrina, Pig-tailed Macaques) after exposure to BNZ and LC. Formation of SHb, unlike MHb, is not thought to be reversible and is considered to be toxic. MHb and SHb levels were measured periodically on a CO-Oximeter. All rhesus (n=8) were dosed intratracheal/intranasal with 56 mg and 280 mg BNZ and with 40 mg of LC in a randomized cross-over design. Pig-tailed macaques (n=6) were dosed with BNZ intranasal 56 mg and with 40 mg of LC. Since no differences in the peak MHb or time to peak (mean +/- SD) were observed among the three macaque subspecies, the data were pooled. LC did not cause MHb or SHb formation above baseline in any monkey.

Descriptors :   *CYANIDES, ANESTHETICS, DRUGS, MEAN, METHEMOGLOBIN, MONKEYS, OXIMETERS, PRODUCTION, REVERSIBLE, SPRAYS, MACAQUE MONKEYS.

Subject Categories : Toxicology
      Pharmacology

Distribution Statement : APPROVED FOR PUBLIC RELEASE