It has been shown that systemic administration of morphine induced a hyperalgesic response at an extremely low dose. We have examined the effect of nifedipine, as a calcium channel blocker, on morphine-induced hyperalgesia in intact and adrenalectomized rats and on hypothalamic-pituitary-adrenal axis activity induced by ultra-low dose of morphine. To determine the effect of nifedipine on hypera...

Opiates have complex effects on seizure thresholds as these substances have both anti and proconvulsive actions in the mammalian brain. A reduction of inhibitory synaptic activity or enhancement of excitatory synaptic activity would be expected to trigger a seizure. This study is designed to determine how morphine and naloxone affect seizures induced by a low Mg2+ perfusate in the whole, intact...

Chronic use of morphine causes rewarding and behavioral sensitization, which may lead to the development of psychological craving. In our previous study, we found that a widely used antitussive dextromethorphan (known as a low affinity NMDA receptor antagonist), at doses of 10-20 mg/kg (i.p.), effectively decreased morphine rewarding in rats. In this study, we further investigated the effects a...

Opioid rotation has been proposed for management of cancer pain. No studies directly investigating dose equivalence between morphine injection (continuous IV administration) and the transdermal fentanyl patch have been reported. Therefore, we examined dose conversion ratios in patients undergoing opioid rotation from morphine injection to fentanyl patches. The subjects consisted of 45 patients ...

conclusions analysis of codeine to morphine metabolism rate is needed when we are using morphine/codeine ratio to rule out abuse of narcotics. wada should consider analysis for the cyp2d6 alleles (main metabolizer of codeine) in case of including morphine/codeine ratio in future prohibited list. the possibility of ultra-rapid cyp2d6 cannot be ruled out in certain results of morphine/codeine nea...

Opiates have complex effects on seizure thresholds as these substances have both anti and proconvulsive actions in the mammalian brain. A reduction of inhibitory synaptic activity or enhancement of excitatory synaptic activity would be expected to trigger a seizure. This study is designed to determine how morphine and naloxone affect seizures induced by a low Mg2+ perfusate in the whole, intact...

objective: crocin and safranal are the main components of saffron, and have many biological functions such as anti-inflammatory and antioxidant activities. in the present study, we investigated the effects of crocin, safranal, morphine, diclofenac and naloxone in combined and separately on formalin-induced orofacial pain in rats. materials and methods: subcutaneous injection of a diluted formal...

the effect of nmda (n-methyl-d-aspartate) receptor antagonists on tolerance to morphine antinociception was investigated in mice. daily subcutaneous administration of 50 mg/kg of morphine hydrochloride for three days induced tolerance to different (3,6 and 9 mg/kg) test doses of morphine. the tolerance obtained was decreased by pretreatment of animals with single or repeated doses of competitiv...