Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033774 (pruritus)
 14,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The administration of narcotics in the subarachnoid or the epidural space is gaining acceptance for postoperative pain relief. However, the potential side effects of intrathecal and epidural use of opioids are the following: early and late respiratory depression, pruritus, nausea and vomiting, urinary retention. Early respiratory depression is low and may occur 6 or 12 hours after the epidural narcotics injection. Many factors contribute to the delayed phase of breathing disorders and a close respiratory monitoring is needed during at least 24 hours after epidural morphine injection. Naloxone can be used to reverse the depression. Pruritus can occur in 10 to 30% of patients receiving morphine; 10 to 30% nausea and vomiting, and urinary retention occurs in 20 to 50% of patients.
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PMID:[Secondary effects of opioids administered by the regional route]. 167 73

To test the hypothesis that opioid agonist activity contributes to the pruritus of cholestasis, a placebo-controlled single-blinded trial of naloxone, an opioid antagonist, was conducted in eight patients with primary biliary cirrhosis. After discontinuation of all conventional antipruritic medications, one or two continuous (24-hour) IV infusions of naloxone (0.2 micrograms.kg-1.min-1) and placebo solution were administered consecutively in an order that was not predetermined. Pruritus was assessed subjectively by means of four hourly recordings of a visual analogue score. In addition, objective measurements of scratching activity that were independent of gross body movements were continuously recorded using an apparatus specifically designed to measure the frequencies associated with this activity. No side effects associated with naloxone infusions were observed. Only scratching activity data obtained for the same periods of day and night during both naloxone and placebo infusions were compared. Naloxone infusions were consistently associated with a decrease in values of the scratching activity index. In addition, in 50% of the patients the infusions were associated with a decrease in visual analogue score. The mean decrease in scratching activity ranged from 29% to 96% (mean, 50%; P less than 0.001). These findings imply that increased opioid agonist activity contributes to scratching activity in cholestatic patients.
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PMID:A controlled trial of naloxone infusions for the pruritus of chronic cholestasis. 173 25

A majority of patients experience pruritus, nausea and/or emesis following epidural morphine administration post-cesarean section. Naloxone or diphenhydramine are commonly used to treat these side effects. Prevention or reduction in the incidence of side effects of epidural morphine is a clinical goal. The purpose of the study was to observe the efficacy of prophylactic administration of hydroxyzine on the incidence and severity of pruritus following the epidural administration of morphine in 40 patients who requested epidural morphine for postoperative pain relief. Group I (n = 20) received saline, while Group II (n = 20) received 50 mg of hydroxyzine ten minutes after the administration of 5 mg epidural morphine. Both solutions were administered by deep intramuscular injection in the thigh area. The results of this investigation demonstrated that hydroxyzine was efficacious in attenuating the incidence of severe pruritus.
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PMID:Epidural morphine pruritus reduction with hydroxyzine in parturients. 191 5

In a double-blind placebo-controlled cross-over study the effects of epidural morphine (4 mg) on somatosensory functions were investigated in 10 healthy volunteers. Detection, pain detection and pain tolerance thresholds to thermal, mechanical and electrical stimuli as well as magnitude rating of short-lasting stimuli of the same modalities were monitored before and for 10 h after epidural administration of 4 mg of morphine or saline. Epidural morphine induced a naloxone-reversible (0.1 mg/kg, i.v.) increase in pain detection threshold to heat and mechanical stimuli and in pain tolerance threshold to heat, mechanical and electrical stimuli. Morphine induced a more pronounced increase in the pain tolerance than in the pain detection threshold. Magnitude rating of short-lasting radiant heat (argon laser) stimuli were reduced by epidural morphine in comparison to placebo while there was no significant difference between the effects of morphine and placebo on magnitude rating of short-lasting mechanical and electrical stimuli. The warm detection threshold was increased (naloxone reversible) by morphine. Segmental distribution of pruritus was reported by 7 subjects following epidural morphine which was replaced by a short-lasting burning sensation following naloxone administration. Naloxone (0.1 mg/kg) preceeded by placebo did not change somatosensory functions. These results indicate that the somatosensory effect of epidural morphine is dependent on the types of afferent fibres activated as well as on the duration and intensity of the stimulus.
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PMID:Quantitative sensory examination during epidural anaesthesia and analgesia in man: effects of morphine. 844 40

In modern anaesthesia various antagonists are used. They provide efficient tools to facilitate better control of pharmacological effects and side effects of drugs routinely used in anaesthesia. Naloxone is a competitive antagonist of opioids without any intrinsic activity. It counteracts respiratory depression, pruritus, sedation and analgesia caused by opioids. It is fast-acting with a duration of action of 45 to 90 min. Several investigators have reported severe side effects of naloxone including hypertension, tachyarrhythmias, left heart failure and cardiac arrest, and hence the use of naloxone must be carefully considered in every single patient. Flumazenil is a competitive antagonist of benzodiazepines. It is a remarkably safe drug and very effective to terminate all benzodiazepine effects in anaesthesia and intensive-care patients. Serious complications caused by flumazenil have been reported in patients receiving benzodiazepines in the treatment of seizure disorders and in patients with mixed intoxications. Neostigmine is one of several antagonists of neuromuscular blocking agents. Its side effects include bradycardia, increased bronchial secretions and increased peristalsis. Indication depends on the results of neuromuscular monitoring. Physostigmine is an unspecific antagonist of the central anticholinergic syndrome, an acute psychosis that may be caused by numerous drugs used in anaesthesia. Generally, antagonists should be carefully titrated. In emergency medicine the use of these antagonists is not recommended; the primary goal is to restore vital functions.
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PMID:[Antagonists in anesthesia]. 854 33

We have investigated whether neurons in superficial laminae of the spinal dorsal horn respond to intracutaneous (ic) delivery of histamine and other irritant chemicals, and thus might be involved in signaling sensations of itch or chemogenic pain. Single-unit recordings were made from superficial lumbar dorsal horn neurons in pentobarbital sodium-anesthetized rats. Chemoresponsive units were identified using ic microinjection of histamine (3%, 1 microl) into the hindpaw as a search stimulus. All superficial units so identified [9 nociceptive-specific (NS), 26 wide-dynamic-range (WDR)] responded to subsequent ic histamine. A comparison group of histamine-responsive deep dorsal horn neurons (n = 16) was similarly identified. The mean histamine-evoked discharge decayed to 50% of the maximal rate significantly more slowly for the superficial (92.2 s +/- 65.5, mean +/- SD) compared with deep dorsal horn neurons (28. 2 s +/- 11.6). In addition to responding to histamine, most superficial dorsal horn neurons were also excited by ic nicotine (22/25 units), capsaicin (21/22), topical mustard oil (5/6), noxious heat (26/30), and noxious and/or innocuous mechanical stimuli (except for 1 unit that did not have a mechanosensitive receptive field). Application of a brief noxious heat stimulus during the response to ic histamine evoked an additive response in all but two cases, followed by transient depression of firing in 11/20 units. Intrathecal (IT) administration of morphine had mixed effects on superficial dorsal horn neuronal responses to ic histamine and noxious heat. Low morphine concentrations (100 nM to 1 microM) facilitated histamine-evoked responses (to >130% of control) in 9/24 units, depressed the responses (by >70%) in 11/24, and had no effect in 4. Naloxone reversed morphine-induced effects in some but not all cases. A higher morphine concentration (10 microM) had a largely depressant, naloxone-reversible effect on histamine responses. Responses of the same superficial neurons to noxious heat were facilitated (15/25), reduced (8/25), or unaffected (2/25) by low morphine concentrations and were depressed by the higher morphine concentration. In contrast, deep dorsal horn neuronal responses to both histamine and noxious heat were primarily depressed by low concentrations of morphine in a naloxone-reversible manner. These results indicate that superficial dorsal horn neurons respond to both pruritic and algesic chemical stimuli and thus might participate in transmitting sensations of itch and/or chemogenic pain. The facilitation of superficial neuronal responses to histamine by low concentrations of morphine, coupled with inhibition of deep dorsal horn neurons, might underlie the development of pruritus that is often observed after epidural morphine.
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PMID:Superficial dorsal horn neurons identified by intracutaneous histamine: chemonociceptive responses and modulation by morphine. 1093 90

Itch is a major symptom of skin disease and is poorly understood, in part due to the lack of adequate small animal models. We show, using iontophoresis of histamine and capsaicin, that it is possible to induce scratching behaviour in both guinea pig and mouse. Use of iontophoresis may obviate the problems of induction of pain as well as itch when injection is used. The behavioural response to capsaicin, however, differs from that seen with histamine, raising the possibility that the use of scratch counts as a method of measuring itch severity needs to be set in the context of other responses. Naloxone partly inhibits scratching in mouse and guinea pig due to histamine. We also show that contact sensitization with 2-4 dinitrochlorobenzene (DNCB) can be used as a simple assay for chronic itch allowing study of scratching over at least a 15-h period. The characteristics of scratching (but not the time course) induced with DNCB are similar to those seen with histamine.
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PMID:Production of acute and chronic itch with histamine and contact sensitizers in the mouse and guinea pig. 1219 Sep 36

This study confirmed the oral anti-inflammatory, analgesic and antihistamine properties of mature fresh leaves (MFL) of Vitex negundo L. (Verbenaceae) claimed in the Ayurveda medicine by orally treating a water extract of the leaves to rats. The early phase (2h) of carrageenan-induced rat paw oedema was significantly (P<0.01) suppressed in an inversely does-dependent (r(2)=1, P<0.01) manner by MFL. The EC(50) was 2g/kg of MFL. In the formaldehyde-induced rat paw oedema test, the 2.5 and 5g/kg leaves significantly (P<0.05) suppressed the inflammation on days 4-6 of the test. In the hot plate test, 2.5 and 5g/kg of MFL showed a significant (P<0.05) and directly dose-dependent analgesic activity at 1h of treatment while the activity was absent in the tail flick test in rats. The EC(50) for the analgesic activity was 4.1g/kg. In the formalin test, 1.25, 2.5 and 5g/kg of MFL significantly (P<0.05) suppressed the pain in both the phases of the test like aspirin. The leaves showed an inversely dose-dependent in vivo antihistamine and in vitro prostaglandin (PG) synthesis inhibition, membrane stabilising and antioxidant activities. Naloxone did not abolish the analgesic activity in the hot plate test. A 5g/kg of MFL did not impair muscle strength and co-ordination and did not induce sedation. The treatment of 5g/kg of MFL did not show signs of acute toxicity or stress. Fourteen-day oral treatment of 5g/kg of MFL significantly increased the serum activity of AST. Flowering of the tree did not abolish the analgesic and anti-inflammatory activities of the leaves. These observations revealed that the fresh leaves of Vitex negundo have anti-inflammatory and pain suppressing activities possibly mediated via PG synthesis inhibition, antihistamine, membrane stabilising and antioxidant activities. The antihistamine activity can produce the anti-itching effect claimed in Ayurveda medicine.
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PMID:Anti-inflammatory and analgesic activities of mature fresh leaves of Vitex negundo. 1286 Mar 8

The present study was performed to develop a new atopic dermatitis model characterized by not only itching but also inflammatory skin using BALB/c mice. From 18 days after the first systemic immunization, daily epicutaneous application of ovalbumin was performed for 2 weeks. Antigen challenge (ovalbumin) resulted in a significant increase of scratching behavior from day 23 to day 32. Moreover, skin symptoms such as erythema/hemorrhage, edema, excoriation/erosion and dryness/desquamation were also observed from day 19 to day 32. The frequency of scratching in the first stage (from day 24 to day 26 after the systemic first immunization) was decreased by chlorpheniramine and epinastine; however, in the last stage (from day 27 to day 30 after the systemic first immunization), both drugs showed no inhibition of scratching behavior. Therefore, an endogenous mediator other than histamine may be responsible for provoking the itching sensation in the last stage. Naloxone dose-dependently reduced the frequency of scratching in the last stage. Moreover, repeated local application of dexametasone significantly inhibited both scratching behavior and skin symptoms from day 24 to day 30. From these findings, it may be concluded that this model is essentially similar to atopic dermatitis in humans and could be used to elucidate the pathogenic mechanisms of atopic dermatitis and to develop appropriate new drugs for therapy.
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PMID:Development of new atopic dermatitis models characterized by not only itching but also inflammatory skin in mice. 1745 67

Pruritus is a well-known manifestation of various cholestatic disorders. Increased opioidergic tone is one of the mechanisms for this. This prospective, uncontrolled study was done to determine the efficacy of intravenous naloxone in pruritus of acute cholestasis. Twenty-two patients with severe pruritus (based on visual analogue scale [VAS] score of 0-100 and associated symptoms) were treated with intravenous naloxone (0.4 mg every 8 hours) for at least 48 hours. Viral hepatitis E was found to be the most common etiology for cholestatic pruritus (n=12). Eighteen patients (81.8%) patients had significant reduction in VAS after 48 hours of starting naloxone; these patients also showed reduction in alkaline phosphatase and gamma glutamyl transpeptidase. There was no side-effect or 'breakthrough' phenomenon noted in any patient over next 6 weeks. Naloxone is safe and efficacious in symptomatic improvement in cholestatic pruritus.
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PMID:Role of intravenous naloxone in severe pruritus of acute cholestasis. 2010 67


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