INTENSITY OF PHYSICAL SIGNS OF MORPHINE WITHDRAWAL SYNDROME IS MORE SEVERE DURING THE REST PHASE

Background and Aim : Many biological events are controlled by the internal clock and exhibit circadian rhythm. Investigations have shown that the circadian rhythm can affect the mechanisms associated with reward so the aim of the current study is to assess the physical signs of morphine withdrawal syndrome during the different circadian time (CT).Methods : Male Wistar rats (250-300 g) were administered 10 mg/kg morphine every 12h, for 10 days (n=20). Control rats received saline with the same protocol (n=20). Thereafter, when they were made dependent on morphine, tested for opioid withdrawal syndrome during day (CT 8-12) and night (CT 20-24).Results : The intensity of physical signs of morphine withdrawal syndrome was more severe during the day or the rest phase compare to the night.Conclusion : It seems that the intensity of opiate withdrawal syndrome is more severe during the rest phase and this must be consider for detoxification of opiate addicts.

Keywords:

Circadian rhythm , morphine , withdrawal syndrome , rat