TY - JOUR T1 - Naloxone Induces Frequent Jumping after Chronic Morphine and Methamphetamine Co-Administration in Rats TT - JF - BCN JO - BCN VL - 5 IS - 1 UR - http://bcn.iums.ac.ir/article-1-467-en.html Y1 - 2014 SP - 42 EP - 47 KW - Polydrug Use KW - Morphine KW - Meth KW - Naloxone KW - Withdrawal Syndrome KW - Rat N2 - Combined use of an opioid with a psychostimulant is popular among drug abusers. Such “polydrug use” may increase drug effects or attenuate adverse effects of either drug alone. We proposed that a combination of methamphetamine (meth) and morphine may change physical opioid withdrawal symptoms. Adult male rats were chronically injected with cumulative subcutaneous (s.c.) doses of morphine, meth or a combination of both drugs within five days. On day six, a challenge dose of the same drug was injected. Two hours later, precipitated withdrawal symptoms were scored within 30 minutes after naloxone (1mg/kg, i.p.) injection. Both frequency and incidence of jumping significantly increased in combined treated animals (P M3 ER -