toluene - National Park Service

Perchloroethylene enhances toxicity of toluene admin orally in
rats. [Smyth HF et al; Amer Ind Hyg Assoc J 30 (5): 470-6
(1969) as cited in USEPA; Health Assessment Document: Toluene
p.15-1 (1982) EPA-800/8-82-008
Toluene and trichloroethylene seem to exhibit competitive
inhibition. [Ikeda M; Int Arch Arbeitsmed 33 (2): 125 (1974).
CFY rats ... on day 12 of pregnancy ... dams were given: 0,
125, 250, 500 and 3,600 mg/cu m ... and 250 mg/kg
acetylsalicylic acid by gavage; two subgroups ... treated with
250 mg/kg acetylsalicylic acid in combination with 3,600 mg/cu
m toluene inhalation were given 0, 2.5, or 5 gm/kg glycine 2
hours before the acetylsalicylic acid dose. ... Toluene was
found to potentiate the toxic effect of acetylsalicylic acid
and to increase both maternal and embryonic toxicity ...
increasing acetylsalicylic acid embryotoxicity caused by
toluene can be warded off by glycine administration. [Ungvary
G et al; Teratology 27 (2): 261-9 (1983).
The metabolism of toluene was found to be inhibited by a large
dose of alcohol in 7 volunteers exposed to 80 ppm. ... When
alcohol was taken during exposure, blood toluene concns were
42-45% greater on average than during exposure with no
alcohol. ... These results suggest that continued alcohol
intake increases the metabolism of toluene, presumably by
inducing the microsomal oxidizing enzyme system in the liver.
[Waldron HA et al; Int Arch Occup Environ Health 51 (4): 365-9
(1983).
The metabolic interaction of toluene and ethanol was studied
in male rabbits having received ethanol (26.0 mmol/kg po),
toluene (5.4 mmol/kg po) or both. Compared with ethanol alone,
toluene given 2 hr after ethanol caused a significantly higher
and more prolonged concentration of blood alcohol. A similar
trend of blood alcohol was observed at the later stage with
toluene given prior to ethanol. On the other hand, with
simultaneous doses of the two substances, the blood toluene
concentration was higher for the first 15-30 min than the
ethanol control and the urinary excretion of hippuric acid, a
main metabolite of toluene, was markedly decreased for the
first 2 hr. The blood ethanol in this group, on the contrary,
was reduced until 1 hr after administration. These results
indicate that toluene and ethanol act reciprocally as
competitive inhibitors in their metabolism after single
administrations. [Takahashi S et al; Arch Toxicol 59 (5):
307-10 (1987).
In an experimental human study, the effect of toluene and
ethanol (alone or in combination) on psychophysiologic
functions was studied in 12 men (22-44 yr of age). Each
subject served as his own control. Subjects were exposed to
toluene by inhalation at a concentration of 300 mg toluene/cu
m air for 4.5 hr. Ethanol was ingested at a dose equivalent to