Ten healthy subjects (four male) of mean age 31 years (range 25-40) took part in a randomized double-blind four-way crossover study to examine the cognitive and psychomotor effects of repeated oral doses of dextropropoxyphene and morphine. Four treatments were compared: dextropropoxyphene napsylate 100 mg, morphine sulphate 10 mg, lorazepam 0.5 mg and placebo. Four doses of each drug were given at 4-h intervals to each subject on four separate study days at least 1 week apart. Cognitive function was assessed using choice reaction time, number vigilance, memory scanning, immediate and delayed word recall, word recognition, picture recognition, critical flicker fusion threshold (CFFT) and subjective measures of alertness, calmness and contentment. Lorazepam impaired the speed of responding on all tasks in which speed was recorded (except digit vigilance) and increased subjective ratings of calmness. Morphine had one major effect, which was to increase the accuracy of responding on the choice reaction time task, at every assessment. Morphine produced some sporadic effects in other tests and an increase in subjective calmness. Dextropropoxyphene impaired performance on choice reaction time and picture recognition. These data show that oral morphine may enhance performance in some measures of cognitive function, whereas dextropropoxyphene (in usual therapeutic doses) seems more likely to cause impairment. Neither opioid has substantial effects on cognition and psychomotor function compared with lorazepam.
Pain is a symptom commonly experienced by people with HIV infection and its prevalence increases as the disease progresses. This article reviews the pathophysiology and clinical presentation of the various opportunistic infections, neoplasms and other HIV-related problems that may manifest as pain. The investigation of these conditions and their specific treatments, where available, are detailed. Because many of the conditions may be refractory to specific therapy, and the duration of investigations may be lengthy, symptomatic treatment should not be delayed. Guidelines are given on the symptomatic management of pain in these patients.
The short-term effects of hemodialysis on the integrity of the central nervous system (CNS) were examined. Evoked potentials (EP) and performance on five neuropsychologic tests were obtained from six patients undergoing maintenance hemodialysis. Measurements were taken 1, 24, 42, and 66b hours following dialysis. A highly consistent relationship between time since dialysis and EP latency was found. EP latencies tended to decrease during the 1-hour and the 24-hour recording sessions (compared to predialysis recordings), the shortest latencies typically occurring during the 24-hour period, then increasing steadily during the 42-hour and 66-hour intervals. EP amplitude was largest 1 hour after dialysis, then decreased progressively with time since dialysis. Performance on two tests of visual-motor speed and accuracy was best 24 hours after dialysis. The results indicate that there are consistent and measurable changes in the responsivity of the CNS which are related to time since dialysis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.