| TABLE 3.1 Psychoactive Doses of THC in Humans
|
| Investigators
| THC Delivery
System
| THC Dose
Administered
| Resulting
Plasma Concentrations
of THC
| Subjects' Reactions
|
| Heishman and
co-workers
(1990)62a
| One 2.75%
THC
cigarette
smoked
| 0.32 mg/kga
| 50-100 ng/ml
| At higher level, subjects
felt 100% "high" and
psychomotor
performance
was decreased;
at 50 ng/ml, subjects
felt about 50%, "high"
|
| Kelly and
co-workers
(1993)85
| 1-g marijuana
cigarette
smoked (2% or
3.5% THC)
| 0.25-0.50
mg/kg"
| Not measured
| Enough to feel
psychological effects
of THC
|
| Ohlsson and
co-workers
(1980)118
| 19-mg THC
cigarette
smoked
(about 1.9'%
THC)
| About 0.22
mg/kg1
| 100 ng/ml
| Subjects felt "high"
|
| | 5 mg of THC
injected
intravenously
| About 0.06
mg/kgb
| 100 ng/ml
| Subjects felt "high"
|
| | Chocolate chip
cookie
containing
20 mg of THC
| About 0.24
mg/kg
| 8 ng/ml
| Subjects rated "high"
as only about 40"%,
|
| Lindgren and
co-workers
(1981)95
| 19-mg THC
cigarette
smoked to
"desired high"
| 12 mg smoked
(7 mg
remained
in cigarette
butt)
| 85 ng/ml
after 3 min.,
35 ng/ml
after 15 min.
| Subjects felt "high"
after 3 min., and
maximally high
after 10-20 min.
(average self-ratings of
5.5 on 10-point scale)
|
| | 5 mg of THC
injected
intravenously
| 0.06 mg/kg'
| 300 ng/ml
after 3 min.,
65 ng/ml
after 15 min.
| Subjects felt maximally
"high" after 10 min.
(average self ratings of
7.5 on a 10-point scale)
|
| aSubjects' weights and cigarette weights were not given. Calculation based on 85-kg bodyweight and 1-g cigarette weight. Note that some THC would have remained in the cigarettebutt and some would have been lost in sidestream smoke, so these represent maximal possible doses. Actual doses would have been slightly less.
bBased on estimated average 85-kg weight of 11 men 18-35 years old.
cBased on approximate 80-kg weight of subjects (including men and women).
|
