1. The amphetamine-like abuse potential of dexfenfluramine (dFEN) was
evaluated using drug discrimination and self-administration procedures
. 2. Male Fischer rats were trained to discriminate either dFEN (1.0 m
g/kg) or d-amphetamine (dAMP; 1.0 mg/kg) from saline in a two-choice d
iscrete-trial avoidance paradigm. 3. In dAMP-trained rats, dFEN (0.5-4
.0 mg/kg) engendered almost exclusively saline-appropriate responding.
In dFEN-trained rats, dAMP (1.0-4.0 mg/kg) engendered entirely saline
-appropriate responding in 3 of 6 rats and intermediate levels of dFEN
-appropriate responding in the remaining animals. 4. Potential reinfor
cing effects of dFEN were also evaluated in 3 male rhesus monkeys trai
ned to self-administer cocaine (i.v.) during daily 60 min sessions und
er a fixed-ratio (FR)-10 schedule. 5. Various doses of dFEN (30-1000 m
u g/kg/infusion) and dAMP (10 mu g/kg/infusion) were substituted for c
ocaine in 4 consecutive daily sessions. In all subjects, dFEN maintain
ed rates of self-administration within the range of rates maintained b
y saline and considerably below those maintained by cocaine and dAMP.
Furthermore, the within-session distribution of responding with dFEN r
esembled that produced by saline. 6. Taken together, these results str
ongly suggest that dFEN will not have amphetamine-like abuse potential
in humans.