Review of Inhalants - ARCHIVES - National Institute on Drug Abuse

Impairments
First, the type, onset, and extent <strong>of</strong> tolerance or dependence
produced by these substances should be determined. For example,
is there a behavioral adaptation to the effects, as acquisition
<strong>of</strong> different effects. or is some physiological tolerance involved?
Similarly, is there any dependence and in which population(s)
does it occur? If so, what are the withdrawal effects
observed for subjects after they have been isolated from the
inhalant scene?
The toxicity <strong>of</strong> most <strong>of</strong> these agents is established. However, it
has been difficult to measure any symptoms <strong>of</strong> toxicity in the
“average” user, There are numerous reports <strong>of</strong> defined impairments
in certain individuals, yet it is unknown if these resulted
from inhalant use or were pre-existing conditions in these subjects.
An identified neurological impairment may be correlated
more with one class <strong>of</strong> solvents than with others; yet there are
almost as many different kinds <strong>of</strong> “solvents” as there are other
drugs <strong>of</strong> abuse. The sorting problem may be endless. Recent
evidence indicates that prolonged exposure to low levels <strong>of</strong> some
<strong>of</strong> these solvents may be carcinogenic (e.g., benzene and triand
perchloroethylene). Findings such as these result in limiting
their use in many household products but may open the way to
the use <strong>of</strong> other compounds with other toxicities. It would be
especially unfortunate if substances were incorporated that produced
irreversible neurological damage not easily detectable by
present testing mechanisms. Also, although toxicities are associated
with certain chemicals, it is not yet possible to extrapolate
how much sooner these effects would occur at the repeated high
dose levels <strong>of</strong> inhalant users. Nor are onsets <strong>of</strong> the dramatic
(e.g., cognitive) impairments known nor how they differ among
the various solvents.
Specific Symptoms <strong>of</strong> Inhalant Toxicity
As discussed in the clinical section, it would be important to
characterize specifically the early manifestations <strong>of</strong> inhalation
toxicity in clinical cases. Then one could possibly devise animal
tests which would identify solvent mixtures that cause these
problems. The cooperation <strong>of</strong> manufacturers and formulators in
providing detailed information on the constituents <strong>of</strong> the products
used could greatly facilitate determination <strong>of</strong> the etiological factors
associated with certain compounds as well as assist in the development
<strong>of</strong> rational approaches to animal studies.
One could possibly measure inhalant effects through a mapping <strong>of</strong>
the visual field, especially through use <strong>of</strong> prospective or other
longitudinal studies. More detailed acuity and visual field tests
could then be pursued for those subjects with abnormalities using
techniques such as computerized axial tomography (see neurology
section). Presently electroencephalogram (EEG) measures would
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