Physical dependence of dihydroetorphine in mice and monkeys (author's transl)
Abstract
The ability of producing physical dependence of dihydroetorphine (DHE) was compared with that of morphine in mice and monkeys.
In nalorphine-challenged mice the average numbers of jumping of the mice after DHE were less than those after morphine and etorphine (E).
In 3 monkeys treated chronically with DHE abstinence syndrome failed to occur in nalorphine (5—8 mg/kg，sc) precipitated withdrawal tests during 108 days.
A low degree of abstinence responses was seen in these monkeys in abrupt withdrawal tests. In contrast to this, severe abstinence syndrome was seen in other 3 morphine-dependent monkeys in both nalorphine precipitated and abrupt withdrawal tests.
In 2 morphine-dependent monkeys (sc 50 mg/kg daily), their abstinence syndrome was suppressed for ⅟2——2⅟2 h by sc DHE 0.43—1.43 μg/kg, while sc morphine 5— 10 mg/kg could suppress their abstinence syndrome for more than 5 h.
These data suggest that DHE produces a relatively low physical dependence in animals.
Keywords:
In nalorphine-challenged mice the average numbers of jumping of the mice after DHE were less than those after morphine and etorphine (E).
In 3 monkeys treated chronically with DHE abstinence syndrome failed to occur in nalorphine (5—8 mg/kg，sc) precipitated withdrawal tests during 108 days.
A low degree of abstinence responses was seen in these monkeys in abrupt withdrawal tests. In contrast to this, severe abstinence syndrome was seen in other 3 morphine-dependent monkeys in both nalorphine precipitated and abrupt withdrawal tests.
In 2 morphine-dependent monkeys (sc 50 mg/kg daily), their abstinence syndrome was suppressed for ⅟2——2⅟2 h by sc DHE 0.43—1.43 μg/kg, while sc morphine 5— 10 mg/kg could suppress their abstinence syndrome for more than 5 h.
These data suggest that DHE produces a relatively low physical dependence in animals.