Morphine and other opioids is the mainstay of cancer pain management. However, considerable fears surrounding their use present barriers to pain control. The aim of this study was to assess the rational use and effectiveness of morphine for management of pain in the palliative care of cancer patients at Ocean Road Cancer Institute (ORCI) in Tanzania. A total of 100 cancer patients who were rece...

High doses of insurmountable antagonists or frequent administration of high doses of agonists are required to alter the potency of opioid agonists to produce discriminative stimuli. In the present study, insurmountable antagonism and repeated agonist treatment were combined to remove or disable a large enough proportion of mu-opioid receptors to alter the potency or maximal effect for four agon...

Some studies have shown that acetylcholine muscarinic receptors involved in the opiate reward. In the present study, the effect of intra-basolateral amygdale (BLA) acetylcholine muscarinic like receptor agonist (physostigmine) and antagonist (atropine) on the acquisition of morphine-induced place preference has been investigated in male Wistar rats. For this purpose, two 22 gauges guide cannula...

Interactions between excitatory amino acids and opioids were examined by studying the ability of the noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 to affect morphine catalepsy and lethality. MK-801 (0.3 mg/kg) reduced the ED50 for morphine-induced catalepsy from approximately 30 mg/kg to less than 10 mg/kg, and reduced the LD50 for morphine from approximately 100 mg/kg t...

BACKGROUND Animal and human studies indicate that genetics may contribute to the variability of morphine efficacy. A recent report suggested that cancer patients homozygous for the 118G allele caused by the single nucleotide polymorphism at nucleotide position 118 in the mu-opioid receptor gene require higher doses of morphine to relieve pain. The purpose of the current study was to investigate...

Introduction: Motor behavior and coordination impairment are known side effects of opioid treatment, yet very few studies have investigated the effects of tramadol on motor behavior, or compared its effect with the effect of an opioid. This study investigates the effects of chronic injection of morphine and tramadol on rat motor function during infancy. Methods: Neonate rats (n=56) were rand...

       Caffeine, an adenosine A1, A2A, and A2B receptor antagonist, is frequently used as an adjuvant analgesic in combination with non steroidal anti-inflammatory drugs or opioids. The aim of this study was to evaluate the effects of caffeine on preventing the development of morphine tolerance and analgesia in mice. In this study, different groups of mice recei...

Delta9-tetrahydrocannabinol (delta9-THC) synergizes with morphine and codeine by releasing endogenous opioids. These studies determined 1) the duration of enhancement of morphine and codeine by delta9-THC, 2) the effect of (delta9-THC on the time course of fully efficacious doses of the opioids, 3) restoration of efficacy of morphine and codeine by delta9-THC, and 4) duration of restoration. Su...