Narcotic Effects Research Articles

Effects of narcotics, including morphine, on visual evoked potential in rats

The side effects of narcotics, including morphine, on the visual system are still unclear; therefore, the present study was undertaken to examine the effects of narcotics on the visual system at each antinociceptive dose by using the evoked potential (VEP) in rats. Morphine (2 or 5 mg/kg) caused a significant increase in the amplitude of early and late VEP components (P 1–N 1, N 1–P 2, P 3–N 3 and N 3–P 4). Fentanyl (0.02 mg/kg) also showed a significant increase in the amplitude of late VEP components (P 3–N 3, N 3–P 4). The effects of morphine and fentanyl on VEP components were antagonized by naloxone (1 mg/kg). On the other hand, (±)-pentazocine (20 mg/kg) reduced the amplitude of the late VEP component (N 3–P 4), and this effect was not antagonized by naloxone. Butorphanol showed no significant changes in early and late VEP components. In conclusion, morphine stimulated the retino-geniculate-cortex pathway and the thalamus-cortical circuit through the opioid receptors, and fentanyl stimulated the thalamus-cortical circuit through the opioid receptors. It can therefore be assumed that VEP is a useful tool for examining the side effects of drugs, including narcotics, on the visual system.

Prospective, Randomized, Double-Blind Trial of Local Anesthetic Infusion and Intravenous Narcotic Patient-Controlled Anesthesia Pump for Pain Management after Free TRAM Flap Breast Reconstruction

: This study assessed the efficacy of a continuous infusion pump system for postoperative pain control at muscle-sparing transverse rectus abdominis musculocutaneous (TRAM) flap donor sites. : In this prospective, randomized, double-blind trial, a dual-catheter continuous infusion pump system was placed in the muscle-sparing TRAM flap donor-site area in all patients. Bupivacaine (0.375%; continuous infusion pump group) or isotonic saline (control group) was infused at 4 ml/hour. All patients also had a patient-controlled anesthesia system delivering intravenous narcotics on demand. Pain scores, patient satisfaction, narcotic use, milestones of surgical recovery, and side effects of narcotics were compared between the two groups. : Forty-eight patients were included in the study (23 continuous infusion pump patients and 25 control patients). The continuous infusion patients used less mean patient-controlled anesthesia narcotic during the first 2 postoperative days (78.0 mg versus 42.7 mg; p = 0.019) and transitioned earlier to oral narcotics than did control patients. Patients' overall pain satisfaction scores were significantly better in the continuous infusion group than in the control group. There were no significant differences between groups with regard to overall abdominal pain intensity scores, total narcotic use, length of hospitalization, incidence of narcotic side effects, or milestones of surgical recovery. : The continuous infusion pump system appears to be a safe and effective method for postoperative donor-site pain management in TRAM flap breast reconstruction patients and should be considered for postoperative donor-site pain management. However, continuous infusion pump local anesthetic delivery to the muscle-sparing TRAM flap donor site did not eliminate narcotic use for pain control.

Postoperative ileus: strategies for reduction

Postoperative Ileus (POI) is a frequent, frustrating occurrence for patients and surgeons after abdominal surgery. Despite significant research investigating how to reduce this multi-factorial phenomenon, a single strategy has not been shown to reduce POI's significant effects on length of stay (LOS) and hospital costs. Perhaps the most significant cause of POI is the use of narcotics for analgesia. Strategies that target inflammation and pain reduction such as NSAID use, epidural analgesia, and laparoscopic techniques will reduce POI but are accompanied by a simultaneous reduction in opioid use. Pharmacologic means of stimulating gut motility have not shown a positive effect, and the routine use of nasogastric tubes only increases morbidity. Recent multi-site phase III trials with alvimopan, a peripherally acting mu-antagonist, have shown significant reductions in POI and LOS by 12 and 16 hours, respectively, by blunting the effects of narcotics on gut motility while sparing centrally mediated analgesia. Use of alvimopan, along with a multi-modal postoperative treatment plan involving early ambulation, feeding, and avoiding nasogastric tubes, will likely be the crux of POI treatment and prevention.

How I Manage Pain After Total Knee Replacement

A comprehensive, perioperative multimodal pain protocol for total knee replacement including use of a periarticular injection is described here. An appropriately designed and implemented multimodal pain protocol will reduce postoperative pain levels, need for narcotic medication, side effects, and adverse events while improving functional recovery (including ambulation, discharge from hospital, and range of motion), and patient satisfaction.

Comparison of Nitrogen Narcosis and Helium Pressure Effects on Striatal Amino Acids: A Microdialysis Study in Rats

Exposure to nitrogen-oxygen mixture at high pressure induces narcosis, which can be considered as a first step toward general anaesthesia. Narcotic potencies of inert gases are attributed to their lipid solubility. Nitrogen narcosis induces cognitive and motor disturbances that occur from 0.3 MPa in man and from 1 MPa in rats. Neurochemical studies performed in rats up to 3 MPa have shown that nitrogen pressure decreases striatal dopamine release like argon, another inert gas, or nitrous oxide, an anaesthetic gas. Striatal dopamine release is under glutamatergic and other amino acid neurotransmission regulations. The aim of this work was to study the effects of nitrogen at 3 MPa on striatal amino acid levels and to compare to those of 3 MPa of helium which is not narcotic at this pressure, by using a new technique of microdialysis samples extraction under hyperbaric conditions, in freely moving rats. Amino acids were analysed by HPLC coupled to fluorimetric detection in order to appreciate glutamate, aspartate, glutamine and asparagine levels. Nitrogen-oxygen mixture exposure at 3 MPa decreased glutamate, glutamine and asparagine concentrations. In contrast, with helium-oxygen mixture, glutamate and aspartate levels were increased during the compression phase but not during the stay at maximal pressure. Comparison between nitrogen and helium highlighted the narcotic effects of nitrogen at pressure. As a matter of fact, nitrogen induces a reduction in glutamate and in other amino acids that could partly explain the decrease in striatal dopamine level as well as the motor and cognitive disturbances reported in nitrogen narcosis.

Letters to the Editor

16 May 2008 Dear Editor, RE: NALOXONE USE IN NEONATAL RESUSCITATION I read with interest the paper by Gill and Colvin,1 concerning the current practice of the administration of naloxone during neonatal resuscitation in Australia. I strongly support their view that the use of this narcotic antagonist without respiratory depressant activity should follow the guidelines set out, to reverse respiratory depression in the newly born infant whose mother received a narcotic within 4 h of delivery once adequate ventilation has been established and maintained. They appropriately condemn the finding that naloxone has been used when no narcotics had been given to the mothers and at times prior to the establishment of adequate ventilation. However, I would not support their view that naloxone should be removed from neonatal resuscitaires. The effect on the newborn following administration of a narcotic to the mother during labour varies considerably from those that are minimally depressed to those that may be profoundly so. However, if the above guidelines are carried out, naloxone, even given intramuscularly, hastens the establishment of normal respiration. Maintaining the baby's colour by effective ventilation usually allows for adequate perfusion thereby permitting an intramuscular injection. Years of clinical practice has shown the efficacy of naloxone, where a reversal of the narcotic respiratory depressant effect is required, provided the infant is adequately ventilated at the time. Yours sincerely

Strategy to Eliminate Pethidine Use in Hospitals

Strategy to Eliminate Pethidine Use in Hospitals

A multipurpose compound for protective coatings

International regulations concerning the protection of both the environment and industrial workers have prompted paint manufacturers and end users to look for suitable replacements for traditional pigments. One of the aims of this investigation was to study the inhibitive properties of ferric benzoate-based paints in simulated marine corrosion condition (3% NaCl solution). Anticorrosive paints containing ferric benzoate were formulated and their performance was evaluated by accelerated (salt fog chamber) and electrochemical (corrosion potential and ionic resistance) tests. In addition, the action of ferric benzoate as a probable antifouling agent was studied through laboratory tests and marine exposure. Ferric benzoate hydrolyzes in seawater producing a pH decrease. In this sense, the effects of the pH and the anion benzoate dissolved in seawater and leached from an antifouling paint were evaluated on Balanus amphitrite nauplii. Although benzoate anion showed an intense narcotic effect on nauplii, the results of this research clearly demonstrated that the antifouling activity is due to the combined action of this anion and the pH decrease, i.e. there exists a synergic effect. Field trials confirmed laboratory assays; paints containing ferric benzoate were effective for inhibiting organism settlement and as corrosion of metal.

Chronic Exposure of the Oligochaete Lumbriculus variegatus to Polycyclic Aromatic Compounds (PACs): Bioavailability and Effects on Reproduction

This study aimed to monitor PAC availability to the oligochaete Lumbriculus variegatus during 28 days of exposure to spiked sediments, in order to obtain reliable chronic effect concentrations for reproduction. Sediment toxicity tests were performed using three pairs of PAC isomers: two homocyclic compounds (anthracene and phenanthrene), two azaarenes (acridine and phenanthridine), and the two main transformation products of the azaarenes (acridone and phenanthridone). During the experiment, available PAC concentrations in pore water (estimated using solid phase microextraction) decreased more than total PAC concentrations in the sediment. Relating effect concentrations to PAC concentrations in pore water and in organisms showed that the two homocyclic compounds caused narcotic effects during chronic exposure, but only one of the four tested heterocyclic PACs caused narcotic effects. The transformation product phenanthridone was not toxic at the tested concentrations (up to 4000 micromol/kg dry sediment), whereas EC50 values for the parent compound phenanthridine and the isomer acridone were below the estimated limit for narcosis, suggesting a specific mode of action. These results demonstrated the unpredictable (isomer) specific toxicity of azaarenes and their transformation products, emphasizing the need of chronic toxicity testing to gain insight into the long-term effects of heterocyclic PACs, which have been overlooked in risk assessment.

Effect of Surfactants and Solutes (Glucose and NaCl) on Solubility of Kavain—A Technical Note

Micelles are self-assembling aggregates formed by surfactant molecules in the liquid media above the critical micellar concentration (CMC) value (1,2). In water medium, the internal portion of micelles is a “hydrophobic core” which can host the drug and increase its solubility in water, its bioavailability and minimize its degradation and loss (3–9). Kavain (Fig. 1) is the most representative kavalactone of the structurally related constituents of Piper methysticum G. Forst. (kava-kava), a tropical plant growing in the South Pacific Islands (10) and traditionally used for its soporific and narcotic effects (10,11). Kava-kava extracts or isolated kavalactones are nowadays used for the treatment of anxiety and improvement of stress disorders, nervous tension and restlessness (10) and recently, a local anaesthetic activity has also been reported (10–12). Thus, in view of a possible therapeutic use of kava-kava extracts or single constituents for local anaesthesia, the behaviour of kavain, tested as a model-molecule, in the presence of micellar carrier systems, relatively unexpensive and simple formulation to topical application, was investigated in order to improve its scarce water solubility. Studies were carried out using different types and concentrations of surfactants (Sodium dodecyl sulfate, SDS, sodium lauryl ether sulfate, SLES and octanoyl-6-O-ascorbic acid, ASC-8, Fig. 1) and physiological solutes (glucose and NaCl). Open in a separate window Fig. 1 Structures of kavain and of the tested surfactants

El <i>Dioscórides</i> de Andrés Laguna en los textos de Cervantes: de la materia medicinal al universo literario

La obra literaria de Miguel de Cervantes ha sido ampliamente estudiada desde numerosos puntos de vista, incluida la perspectiva médica. En el presente trabajo defendemos la hipótesis de que el Dioscórides de Andrés Laguna fuese la fuente utilizada por Cervantes en sus pasajes literarios relativos a aspectos terapéuticos, sobre todo en relación con las plantas dotadas de virtudes medicinales. Esta obra, existente en la biblioteca particular de Cervantes, es el único libro de carácter médico citado por el literato en toda su producción (El Quijote). Además de las plantas medicinales citadas en sus obras, de las que hemos identificado la achicoria, adelfa, beleño, opio, romero, ruibarbo, tabaco, tamarisco, tártago y verbena, Cervantes también parece conocer los efectos de diferentes preparados farmacéuticos elaborados a base de plantas medicinales (ungüento blanco, aceite de Aparicio, filtros narcóticos, etc.). Nuestra hipótesis se justifica en el empleo, por parte de Cervantes, de descripciones similares a las aportadas por Laguna en su Dioscorides (los efectos alucinógenos de los ungüentos de brujas en El coloquio de los perros, las propiedades terapéuticas del romero en el tratamiento de heridas y traumatismos en el Quijote, los efectos narcóticos del opio en El celoso extremeño, los efectos psicodislépticos de algunos filtros de amor en El licenciado Vidriera, los efectos tóxicos de algunos venenos en La española inglesa), e incluso, en algún caso, de citas casi literales de los comentarios de Laguna (el efecto purgante del exceso de cólera del romero en el Quijote).

Controlling pain after total hip and knee arthroplasty using a multimodal protocol with local periarticular injections

In this prospective randomized study, patients undergoing total hip (THA) or knee arthroplasty (TKA) were randomized to either a study group receiving periarticular injections or a control group receiving patient-controlled analgesia with or without femoral nerve block (TKA patients). All patients received a comprehensive multimodal perioperative protocol. Pain, recovery of functional milestones, and overall satisfaction were assessed. The THA study group demonstrated significantly lower average pain scores and higher overall satisfaction than the control group. There was no significant difference in pain scores between the study and control groups in the TKA cohort. Both study groups demonstrated lower narcotic usage and side effects as well as improved early functional recovery. Periarticular injection with a multimodal protocol was shown to safely provide excellent pain control and functional recovery and can be substituted for conventional pain control modalities.

The Relationship of Opiate Analgesia to Quality of Life in an Adult Sickle Cell Population.

Pain is a limiting factor in the daily life activities of sickle cell disease (SCD) patients. Opioid analgesics are widely used for management of SCD-related chronic pain in the community. To date there have been no studies on the use of opioids and their impact on quality of life (QoL) measures in this population. Patients on long-term opioid pain management may also be on hydroxyurea (HU), which is often used to decrease the frequency of painful episodes and other SCD sequelae. HU is also known to affect some QoL measures. The aim of this study was to determine the effect of opioid analgesia on QoL measures in an adult SCD population. This study included 185 patients, 92 females and 93 males, from the outpatient clinic at Duke University Medical Center. 117 patients either had homozygous SCD or were doubly heterozygous for Sβ0 thalassemia; 68 patients were of different genotypes. Data were collected by patient interviews as well as review of medical records after informed consent. The Medical Outcome Study 36-item Short Form (SF-36) was used to determine QoL measures, and the results were scored in standard fashion. Differences in variables of interest between narcotic users and narcotic non-users were analyzed using t-tests. ANOVAs were used to identify combined effects of narcotics, HU and their interaction with SF-36 scores. Gender, age and genotypes were included as covariates. Patient data were classified in 4 groups based on report of regular use of opioids (at least 30 days within the preceding year) and HU (any use during the preceding year) as follows: no HU or narcotics (none); narcotics only; HU only; and narcotics and HU. SF-36 scores for all physical and mental domains were significantly lower in individuals on opiates vs those not on opiates, in all age groups (p<.01). Controlling for HU use did not affect the association of opioid use with lower SF-36 scores. We also examined the relationship between hemoglobin, white blood cell count (WBC) and oxygen saturation in the different medication groups. WBC counts were significantly higher in individuals using opioids when compared to those who were not on opioids. Patients on HU and narcotics also had higher WBC than those on HU alone. The frequency of hospitalization was significantly higher in the opioid only group, as compared to the other 3 groups (p=.02). While HU was found to have a positive impact on certain aspects of QoL, it added very little to QoL in individuals who were on both HU and narcotics. Since the efficacy of HU was strongly related to the decrease in WBC, we compared the mean values of WBC in all medication groups. HU significantly lowered the WBC count, but the concurrent use of opioids partially obliterated this effect. This cannot be explained by poor compliance, as the mean WBC were lower in the HU and opiates than in the opiate only group. Our results suggest that further studies are needed to determine whether other factors play a role in QoL outcomes. Other pain management strategies should also be investigated due to the apparent association of opioid analgesia with lower QoL in this patient population. [Display omitted]

Alvimopan: a peripheral acting µ-opioid-receptor antagonist used for the treatment of postoperative ileus

Alvimopan is a peripherally acting µ-opioid-receptor antagonist that has been investigated for the treatment of postoperative ileus. Postoperative ileus, defined as a disruption in normal bowel motility, is a significant cause of morbidity and increased hospital costs for the surgical patient. The etiology of postoperative ileus is multifactorial and includes neurogenic, inflammatory and pharmacologic influences. Until this point, there has been no successful pharmacotherapy to treat bowel hypomotility following abdominal surgery. Alvimopan blocks the negative effects of opioids in the gastrointestinal tract without compromising central opioid-based analgesia. Alvimopan has been shown to significantly decrease the effect of narcotics on bowel function, hasten the return of bowel function and decrease hospital stay in the postsurgical patient, without affecting the analgesic effect of opioids. Alvimopan, at the time of writing, is not yet available for general use and is awaiting FDA approval. Currently, t...

China Aoxing Pharmaceutical Company has launched injectable generic naloxone 0.4mg, 1mg, 2mg and 4mg in China for the reversal of narcotic drug effects.

China Aoxing Pharmaceutical Company has launched injectable generic naloxone 0.4mg, 1mg, 2mg and 4mg in China for the reversal of narcotic drug effects.

Acute pain and narcotic use does not impair the ability to provide informed consent: Evaluation of a competency assessment tool in the acute pain patient

Patients evaluated in acute pain will often have narcotics withheld until after the patient has been evaluated by a surgeon and has given informed consent. Concern that the patient would have impaired judgment due to narcotic effects often prevents the administration of timely pain relief. The Hopkins Competency Assessment Tool (HCAT) is a validated instrument for both psychiatric and medical patients; it has not been validated to evaluate drug effects on judgment. Thirty consecutive patients agreed to participate in the trial over a 12-month period. The HCAT was administered prior to the planned major elective procedure and repeated on each postoperative day up to and including postoperative day 5. Narcotic use (as morphine equivalents), HCAT scores, demographic data, and surgical procedures were recorded. The average age of our patients was 53 years. Twenty-seven patients passed the initial HCAT, and one patient failed subsequent exams. No correlation was seen between HCAT score and narcotic dose. Narcotic administration sufficient for pain control does not impair the ability to provide informed consent. The only patient who failed the HCAT after an initial passing score was somnolent on the narcotic dose.

Lethal and sublethal effects of naphthalene and 1,2-dimethylnaphthalene on the marine copepod Paracartia grani

Here we evaluate the effects of two quantitatively very important components of the water soluble fractions of fuel oils (naphthalene and 1,2-dimethylnaphthalene, hereafter NAPH and C2-NAPH, respectively) on the survival, feeding and egg production rates, and viability of eggs of the coastal copepod Paracartia (Acartia) grani. Acute toxicity responses resulted in lethal concentrations (LC50) of 2,535 and 161 μg l−1 for NAPH and C2-NAPH, respectively, with no evidence of narcotic effects. Hydrocarbon-specific differences in the toxicity response indicate that sublethal effects (EC50) on feeding by C2-NAPH were likely driven by induced mortality, whereas NAPH has direct negative effects on feeding. Sublethal effects on egg production rates followed a similar detrimental pattern to the one exhibited by feeding rates, suggesting that the lower egg production rates were mediated by the decrease in feeding rates. At the exposure time tested (24 h), the 50% reduction effective concentrations (EC50) determined for sublethal effects were relatively high in comparison with hydrocarbons’ concentrations found under natural circumstances. Long exposure (4 days) of P. grani adults to the tested hydrocarbons at concentrations well below the recorded EC50, however, had no significant effects on feeding, egg production and hatching rates. The viability of the eggs was either not affected or only slightly influenced when healthy eggs were incubated under very high concentrations (up to 6,400 and 700 μg l−1 NAPH and C2-NAPH, respectively). The significance of the effects of oil spills on marine zooplankton communities is discussed in light of the results presented in this study.

Long-term Neurocognitive Function After Critical Illness

Until relatively recently, critical care practitioners have focused on the survival of their patients and not on long-term outcomes. The incidence of chronic neurocognitive dysfunction has been underestimated and underreported, and only recently has it been studied in critically ill patients. However, neurocognitive outcomes have been the subject of extensive investigation in other medical populations for many years. Review of the current literature regarding long-term neurocognitive outcomes following critical illness. Data from studies to date indicate that critical illness can lead to significant neurocognitive impairments. The neurocognitive impairments persist for months and years, and may have important consequences for quality of life, the ability to return to work, overall functional ability, and substantial economic costs. The mechanisms of the neurocognitive impairments are not fully understood but likely include delirium, hypoxia, glucose dysregulation, metabolic derangements, inflammation, and the effects of sedatives and narcotics among other factors. The contributions of these factors may be particularly significant in patients with preexisting vulnerabilities for the development of cognitive impairments such as mild cognitive impairment, dementia, prior traumatic brain injury, or other comorbid disorders associated with neurocognitive impairments. Current research indicates that neurocognitive sequelae following critical illness are common, may be permanent, and are associated with impairments in daily function, decreased quality of life, and an inability to return to work. Research needs to be done to better understand the prevalence, nature, risk factors, and nuances of the neurocognitive impairments observed in ICU survivors.

Is khat-chewing associated with HIV risk behaviour? A community-based study from Ethiopia

This study examines the possible association between the stimulant khat and risky sexual behaviour that might aggravate the spread of HIV. A community-based cross-sectional survey involving 4 000 individuals and focus group discussions were conducted to assess the attitudes and perceptions of an Ethiopian population towards the habit of khat-chewing and its possible association with risky sexual behaviour. All participants in the focus group discussions and 38% of the survey respondents were of the opinion that behaviours associated with the mild narcotic effects of khat are conducive to casual sex, and hence constitute an increased risk for contracting and spreading HIV. A significant shift towards casual sex practices was observed in response to the effects induced by the substance, and a strong association was observed between khat-chewing, indulgence in alcohol and recourse to risky sexual behaviours. There was no significant difference in the use or non-use of condoms among those male chewers who admitted resorting to casual sex after khat-chewing. We suggest that HIV/AIDS programmes in certain regions should address the habitual use of khat and other substances of potential abuse as part of their intervention efforts to curb the epidemic.

Effects of naphthalene on metabolic rate and ammonia excretion of juvenile Florida pompano, Trachinotus carolinus

Bioassays were performed to determine the level of 96h-LC50 of naphthalene in Trachinotus carolinus and to investigate the effects of different concentrations of naphthalene, after acute (50-min and 24-h) and chronic (12-day) exposures, on the physiological parameters of the species. The 96h-LC50 at 24 °C was 2.83 ppm of naphthalene. Fish after acute exposures show a tendency to increase specific oxygen consumption by virtue of naphthalene concentrations. After chronic exposures, however, a decrease was observed at the highest concentration evidencing a narcotic effect of naphthalene. Ammonia excretion was reduced significantly, as compared to that of the controls, in all the exposed organisms. The O:N ratio indicated a tendency of using lipidic substrate to supply metabolic demands after long term exposition to naphthalene or to high concentrations of the pollutant. The effects caused by naphthalene were time and dose dependent for Florida pompanos.