Articles: pain.
-
Clonidine and morphine depress nociceptive reflex responses when given alone; when given in combination, the effect of each is potentiated by the other. The present study was designed to test if activity in ascending axons evoked by electrical stimulation of afferent C-fibers in the sural nerve of the rat also exhibits potentiation of the depressant effects of clonidine and morphine when both drugs are administered in combination by intrathecal (i.t.) injection to the lumbar spinal cord. For comparison, experiments were also carried out on the tail-flick response in rats. ⋯ The dose-response curve of depression by morphine alone of C-fiber-evoked activity (ED50 8 micrograms) is significantly shifted by clonidine to the left (ED50 0.9 microgram). Naloxone (0.2 mg/kg) injected intravenously did not affect the inhibition of ascending activity caused by clonidine at the highest dose (35 micrograms), but it reduced the depressant effect of combined i.t. administration of clonidine and morphine. The potentiation of the antinociceptive effects of clonidine and morphine given in combination are possibly due to actions of the two drugs at different sites between the nociceptive afferents and the neurons sending their axons to the brain.
-
Pain expression in neonates instigated by heel-lance for blood sampling purposes was systematically described using measures of facial expression and cry and compared across sleep/waking states and sex. From gate-control theory it was hypothesized that pain behavior would vary with the ongoing functional state of the infant, rather than solely reflecting tissue insult. Awake-alert but inactive infants responded with the most facial activity, consistent with current views that infants in this state are most receptive to environmental stimulation. ⋯ Sex differences were apparent in speed of response, with boys showing shorter time to cry and to display facial action following heel-lance. The findings of facial action variation across sleep/waking state were interpreted as indicating that the biological and behavioral context of pain events affects behavioral expression, even at the earliest time developmentally, before the opportunity for learned response patterns occurs. Issues raised by the study include the importance of using measurement techniques which are independent of preconceived categories of affective response.
-
Different types of pain patients used visual analogue scales (VAS) to rate their level of pain sensation intensity (VAS sensory) and degree of unpleasantness (VAS affective) associated with pain experienced at its maximum, usual, and minimum intensity. Women used the same VAS to rate their labor pain during early, active, and transition phases of stage I and in pushing (stage II). ⋯ Affective VAS but not sensory VAS ratings of pain were considerably reduced when women in labor focused on the birth of the child as compared to when they focused on their pain. The results underscore the importance of utilizing separate measures of the sensory intensity versus the affective dimension of clinical pain and provide evidence that the affective dimension of different types of clinical pain is powerfully and differentially influenced by psychological contextual factors.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Analgesic efficacy and side-effect profile of paracetamol/codeine and paracetamol/dextropropoxyphene after surgical removal of a lower wisdom tooth.
A double-blind randomized analgesic trial was carried out on 180 patients undergoing surgical removal of an impacted lower wisdom tooth. The patients took their first dose of either 1000 mg paracetamol plus 60 mg codeine or 650 mg paracetamol plus 65 mg dextropropoxyphene when pain appeared after the decline of the local anaesthesia. If needed, another two doses were available during the observation period (less than or equal to 10 h). ⋯ Sufficient pain relief was obtained in most patients. The pain reduction after the first dose was 64% in the group receiving paracetamol/codeine compared with 53% in the group receiving paracetamol/dextropropoxyphene and the mean durations of effect of the first dose were 6.6 and 5.8 h, respectively. Side-effects appeared in all patient groups but were most frequent in women taking paracetamol/codeine.
-
Clinical Trial Controlled Clinical Trial
Analgesic efficacy of paracetamol/codeine and paracetamol/dextropropoxyphene in pain after episiotomy and ruptures in connection with childbirth.
Pain after episiotomy and/or perineal/vaginal rupture in childbirth is severe in many patients and in most cases it can be treated with oral analgesics. In this trial the efficacy and side-effect profile of two combination analgesics, paracetamol/codeine and paracetamol/dextropropoxyphene hydrochloride, were compared in post-partum pain after episiotomy and/or rupture of the perineum. Eighty-five patients were analysed for efficacy and 96 were included in an analysis of side-effects. Paracetamol/codeine was shown to give faster and more efficient pain relief while not causing constipation or other troublesome side-effects.