Cellular inflammatory responses during immediate, developing, and established late-phase allergic cutaneous reactions: effects of cetirizine

BACKGROUND

In some previous studies, the antihistamine cetirizine has inhibited both developing (at 6 hours) and established (at 24 hours) gross late-phase skin reactions (LPR) to pollen antigens, possibly relevant to clinical drug effects. However, the effects of cetirizine at the histologic level require further definition.

OBJECTIVE

To characterize cetirizine effects on gross and histologic inflammatory events from 20 minutes to 24 hours after intradermal antigen challenge in sensitive patients.

METHODS

Gross and histologic responses to intradermal pollen antigen, codeine, histamine, and buffer diluent were assessed during randomized 7-day treatments with cetirizine and placebo. Accumulated neutrophils, eosinophils, activated (EG2+) eosinophils, and T lymphocytes were quantitated. The degrees of extracellular deposition of lactoferrin from neutrophils and eosinophilic cationic protein (ECP) from eosinophils were also assessed.

RESULTS

During placebo treatment, wheal-and-flare responses were significantly greater to antigen at 20 minutes (p < 0.01) and induration at 6 hours (p < 0.01) at antigen challenge sites than at buffer diluent sites. During cetirizine treatment, these wheal-and-flare responses to antigen were inhibited significantly (p < 0.01) but gross LPRs were not affected. During placebo treatment, significantly more cells per high-power field were found in antigen sites than in buffer sites of neutrophils at 20 minutes (p < 0.01) and 24 hours; than in eosinophils at 20 minutes, 6 hours, and 24 hours (p < 0.01 for each); than in EG2+ cells at 20 minutes (p = 0.004), 6 hours (p = 0.001), and 24 hours (p = 0.02); and at T lymphocyte sites at 24 hours (p = 0.001). Extracellular deposition of lactoferrin and ECP was significantly greater at antigen sites than at buffer sites at 6 and 24 hours. Cetirizine treatment had no significant effect on these responses.

CONCLUSION

Neutrophils, eosinophils, and T lymphocytes were persistently more common at antigen sites than at buffer sites through 24 hours. Many of these neutrophils and eosinophils were activated, releasing more lactoferrin and ECP into the extracellular dermis for at least 24 hours after antigen challenge. Cetirizine inhibited gross immediate responses to antigen, but not the gross LPR nor the cellular inflammatory responses seen in such LPR sites.

Subhypnotic propofol does not treat postoperative vomiting in children after adenotonsillectomy

PURPOSE

To investigate the efficacy of a subhypnotic dose of propofol to treat vomiting in children after adenotonsillectomy.

METHODS

Two hundred and fifty-two children, aged 2-12 yr, underwent a standardized anaesthetic opioid administration, and postoperative care after adenotonsillectomy, adenoidectomy or tonsillectomy. A prospective, double-blinded, placebo-controlled study was performed in 70 of the patients who retched or vomited after surgery and who had intravenous access. Patients were assigned randomly to receive either 0.2 mg.kg-1) propofol (n = 35), or placebo (intralipid 10%, n = 35).

RESULTS

The overall incidence of vomiting during the first 18-24 hr was 50%. Of those who had received propofol after the first episode of vomiting, 63% relapsed requiring a rescue antiemetic compared with 57% of those who had received intralipid (P = NS). Of the children who received propofol, 54% experienced pain on injection and 46% were mildly sedated compared with 3% and 11%, respectively, in the placebo group (P < 0.003).

CONCLUSION

We conclude that an intravenous bolus of 0.2 mg.kg-1 propofolis not effective in the treatment of postoperative vomiting in children after adenotonsillectomy when a standardized anaesthetic with thiopentone, halothane, nitrous oxide, and 1.5 mg.kg-1 codeine phosphate is used, but it does cause sedation and pain on injection.

Preoperative hypnotic techniques reduce consumption of analgesics after surgical removal of third mandibular molars: a brief communication

The effects of hypnosis in connection with surgery have been described in many clinical publications, but few controlled studies have been published. The aim of the present study was to evaluate the effects of preoperative hypnotic techniques used by patients planned for surgical removal of third mandibular molars. The patients were randomly assigned to an experimental (hypnotic techniques) or a control (no hypnotic techniques) group. During the week before the surgery, the experimental group listened to an audiotape containing a hypnotic relaxation induction. Posthypnotic suggestions of healing and recovery were given on the tape together with advice regarding ways to achieve control over stress and pain. The control group received no hypnotic intervention. Only one surgeon who was not aware of patient group assignments performed all the operations. Thirty-six patients in the control group were compared to 33 patients in the experimental group. Anxiety before the operation increased significantly in the control group but remained at baseline level in the experimental group. Postoperative consumption of analgesics was significantly reduced in the experimental group compared to the control group.

Blockade of peripheral neuronal barrage reduces postoperative pain

Peripheral afferent neuronal barrage from tissue injury produces central nervous system hyperexcitability which may contribute to increased postoperative pain. Blockade of afferent neuronal barrage has been reported to reduce pain following some, but not all, types of surgery. This study evaluated whether blockade of sensory input with a long-acting local anesthetic reduces postoperative pain after the anesthetic effects have dissipated. Forty-eight patients underwent oral surgery with general anesthesia in a parallel group, double-blind, placebo-controlled study. Subjects randomly received either 0.5% bupivacaine or saline intraoral injections, general anesthesia was induced with propofol, a non-opioid anesthetic, and 2-4 third molars extracted. Subjects were assessed at 24 and 48 h for postoperative pain and analgesic intake. Blood samples were collected at baseline, intraoperatively and at 1-h intervals postoperatively for measurement of beta-endorphin as an index of CNS response to nociceptor input. Plasma beta-endorphin levels increased significantly from baseline to the end of surgery in the saline group in comparison to the bupivacaine group (P < 0.05), indicating effective blockade of nociceptor input into the CNS by the local anesthetic. Pain intensity was not significantly different between groups at 24 h. Pain at 48 h was decreased in the bupivacaine group as measured by category scale and graphic rating scales for pain and unpleasantness (P < 0.05). Additionally, subjects in the bupivacaine group self-administered fewer codeine tablets for unrelieved pain over 24-48 h postoperatively (P < 0.05). These data support previous animal studies demonstrating that blockade of peripheral nociceptive barrage during and immediately after tissue injury results in decreased pain at later time points. The results suggest that blockade of nociceptive input by administration of a long-acting local anesthetic decreases the development of central hyperexcitability, resulting in less pain and analgesic intake.

Histamine is released in the wheal but not the flare following challenge of human skin in vivo: a microdialysis study

BACKGROUND

The mediator mechanisms of the cutaneous wheal and flare response, which underlies allergic skin and urticarial conditions, are controversial. The wheal results primarily from a direct effect of histamine on the local vascular bed but to what extent does histamine diffuse within the wheal? The flare is neurogenic, in origin, being disseminated within the dermis by axon reflexes, but do the neuropeptides released from the nerve endings cause the vasodilatation directly or do they induce the further release of histamine which then transduces the flare?

OBJECTIVE

We have addressed these questions by inserting 216 microns diameter microdialysis fibres into the dermis within the different areas of the wheal and flare to monitor changes in histamine levels provoked by intradermal injections of histamine, allergen, codeine and substance P. Twenty-one subjects participated in the investigations.

RESULTS

The histamine concentration in unprovoked skin was 10.5 +/- 0.6 nM. As the dialysis efficacy was approximately 50%, this equates to tissue concentrations of 20 nM. All provicants released large amounts of histamine at the injection site, maximum histamine levels being 337-1293 nM. Diffusion of histamine within the wheal was poor, levels at 2.3 mm and 3.7 mm from the site of injection being 4-22% and 0.2-3.7% respectively of those 1 mm from the injection site. No increased histamine levels were detected in the flare with any provicant. Atraumatic delivery to the skin of histamine in infusion concentrations of 30-10,000 nM caused concentration-related effects, at least 100 nM being necessary to induce a significant increase in skin blood flow, a threshold of 300-1000 being required to stimulate a visible flare and a measurable erythema, and 3000-10,000 nM being the minimum for induction of a wheal. Thus the skin blood vessels and nerves are responsive to histamine, but at relatively high concentrations.

CONCLUSIONS

These data support the theory that the flare reaction to focal histamine injection or release is a neurogenic reflex not involving histamine release at its effector end.

Comparison of the efficacy of paracetamol versus paracetamol, codeine and promethazine (Painstop) for premedication and analgesia for myringotomy in children

This prospective double-blinded study compared the analgesic effectiveness and incidence of complications of a compound preparation Painstop (Paedpharm Pty Ltd) containing paracetamol 12 mg, codeine 0.5 mg and promethazine 0.65 mg per 1.0 ml, dosage 1.0 ml/kg, with paracetamol 20 mg/kg. Ninety-five children aged 1 to 12 years, ASA 1-2, scheduled for myringotomy and drain tuber insertion as a day procedure were randomized to receive Painstop or paracetamol 30 to 60 minutes prior to surgery. Preoperative drowsiness and complications on induction and postoperative sedation, pain and times to achieve goals were recorded. The groups were comparable for age, gender, weight, anaesthetic technique and duration of surgery. Times to eye opening (P = 0.05) and first oral intake (P = 0.006) were significantly longer in the Painstop group. There was, however, no difference in times to discharge. Late sedation was more common in the Painstop group (P = 0.03). Pain scores were low and similar in both groups and the need for additional analgesia was uncommon.

Superiority of oral ketamine as an analgesic and sedative for wound care procedures in the pediatric patient with burns

The management of pain and anxiety in pediatric patients with burns includes the challenge of striking a balance between inadequate versus excessive medication. Ketamine provides effective sedative, analgesic, and amnestic properties for children and has been used intravenously with good results. With its recent availability as an elixir, we speculated that ketamine given orally may provide effective analgesia and sedation during wound care procedures with a wide safety margin. To test this hypothesis, 19 pediatric patients with burns undergoing a wound care procedure were randomized to receive either ketamine oral suspension or 300 mg acetaminophen with codeine phosphate and diphenhydramine, our prior standard for analgesia and sedation. Intensity of pain was determined with use of a color slide algometer and demonstrated more than 400% reduction in pain with the use of ketamine (p < 0.05). The Ramsey scale was used to quantitate sedation and demonstrated that ketamine improved sedation by 360% (p < 0.05). These results substantiate improved analgesia and sedation with oral ketamine as compared to a commonly used narcotic and sedative in facilitating wound care procedures in pediatric patients with burns. These findings suggest that expanded use of ketamine oral suspension may be.

A comparison of patient-controlled and fixed schedule analgesia after orthognathic surgery

PURPOSE

The purpose of this prospective study was to compare the effectiveness of patient-controlled intravenous (i.v.) opioid analgesic administration (PCA) with fixed schedule and dosage oral/rectal administration of naproxen, and opioid analgesics intramuscularly/orally as needed (i.m./p.o. prn) for postoperative analgesia over a period of 48 to 56 hours after surgery.

PATIENTS AND METHODS

There were 75 orthognathic patients aged 25.73 +/- 8.01 years, subdivided into three study groups of 25: codeine group (8 males, 17 females); naproxen group (5 males, 20 females) and PCA group (8 male, 17 females). The degree of analgesia was assessed every 4 hours from 8:00 AM to 8:00 PM hours on days 1 and 2 postsurgery using a visual analog scale (VAS). Mean daily and mean overall VAS scores were treated as parametric data and were analyzed accordingly. Mean daily VAS scores also were categorized as comfort days when mean scores were less than 3.0 cm, and as discomfort days when mean scores were equal to or greater than 3.0 cm. ANOVA were used to analyze patient demographics, pain scores, surgical time, fentanyl used during general anaesthesia, analgesic morphine equivalents, and vital signs. Chi-square tests were used to analyze sex, comfort (discomfort) days, and nausea and vomiting. Mean VAS ratings were analyzed using independent t-tests.

RESULTS

The three groups were matched in demographics, surgical time, fentanyl used, and sex. The PCA group used less than half the amount of morphine equivalent as the codeine group (P = .0001). Both the naproxen and the PCA groups were significantly more comfortable than the codeine group during day 1 and day 2 postsurgery. The codeine group had significantly more episodes of nausea than either the naproxen or the PCA groups.

CONCLUSION

In patients undergoing orthognathic surgery, the naproxen and PCA regimens provided better analgesia than the codeine regimen.

Urine and plasma pharmacokinetics of codeine in healthy volunteers: implications for drugs-of-abuse testing

Thirteen healthy volunteers participating in an open and randomized study received two single doses (25 and 50 mg) of codeine orally two weeks apart. Urine concentrations of opiates were studied for 96 h, and plasma concentrations of codeine and the metabolites codeine-6-glucuronide (C6G), morphine, morphine-3-glucuronide (M3G), and morphine-6-glucuronide (M6G) were monitored for 24 h. Plasma was analyzed by high-performance liquid chromatography. Measurements of urine were made with the EMIT opiate-screening assay and with gas chromatography-mass spectrometry for total (conjugates liberated by acid hydrolysis) codeine, morphine, and norcodeine. In urine, the ratio between total recovered morphine and codeine as expressed in percent ranged from 2.3 to 23.3% with a mean value of 9.8%. This ratio increased with time, and, in all but three subjects, rose to greater than 1 after 22-36 h. In 58% of cases, this occurred within the detection time in the EMIT assay. The detection time in the EMIT screening assay was found to be 20-39 h after the 25-mg dose and 30-52 h after the 50-mg dose. Elimination rates calculated from urine data corrected for creatinine concentration showed that morphine was eliminated more slowly than codeine. In plasma, the highest concentrations and area-under-curve values were observed for C6G, followed by codeine and M3G. All compounds had peak plasma values 1-2 h after dosing. The elimination of M3G was slower than that of C6G. We concluded that the relative proportion of codeine and morphine varies both between individuals and as a function of time and that morphine may be present in concentrations above those of codeine even after moderate and single doses of codeine. This must be taken into consideration when interpreting the presence of opiates during drugs-of-abuse testing.

A double-blind comparison of codeine and morphine for postoperative analgesia following intracranial surgery

Codeine and morphine were compared in a double-blind study of postoperative analgesia in 40 patients after intracranial neurosurgery. Eighteen patients received codeine phosphate 60 mg and 18 morphine sulphate 10 mg, both by intramuscular injection; 4 patients (10%) required no analgesia. Both drugs provided analgesia within 20 min of injection but morphine was more effective than codeine beyond 60 min (p = 0.01). Fewer doses of morphine than codeine were required (p = 0.003). Nine patients requested one dose of morphine and 9 two doses. Seven patients required three doses of codeine and 1 patient required four doses. Neither drug caused respiratory depression, sedation, pupillary constriction or unwanted cardiovascular effects. We conclude that, in the doses used, morphine is a safe alternative to codeine for analgesia after neurosurgery and has a more persistent action.

Inhalation exposure to volatilized opioids produces antinociception in mice

The goal of this study was to determine whether opioids of varying potencies are pharmacologically active via the inhalation route of administration in mice. The opioids evaluated included heroin, morphine, codeine, fentanyl and meperidine; each of these drugs has the potential for abuse in humans. Inhalation exposure to each of these compounds produced antinociception in a dose-dependent manner as assessed in the tall-flick test. No pyrolysis products were detected after heating either morphine or codeine at 250 degrees C for 5 min. Although 6-acetylmorphine was found after heating heroin, it accounted for less than 5% of the recovered sample. Heroin was somewhat less potent by inhalation administration than i.v. injection, with ED50 values of 1.6 and 0.69 mumol/kg, respectively. In contrast, the relative potency of morphine was substantially greater when inhaled than when injected, with respective ED50 values of 0.77 and 3.9 mumol/kg. Whereas the body to brain ratios of [3H]morphine were approximately 8 and 20 for inhalation exposure and i.v. injection, respectively, the ratio for heroin was approximately 5 regardless of administration route. This pattern of results suggests that the increase in morphine potency upon inhalation may have resulted from an increased accessibility to the brain compared with i.v. injection. Finally, naloxone reversed the antinociceptive effects of volatilized heroin, but neither the kappa selective antagonist nor-binaltorphimine nor the delta selective antagonist naltrindole blocked this antinociception, which suggests the involvement of mu opioid receptors. These findings taken together suggest the potential for the abuse of a variety of opioids, in addition to heroin, through the inhalation route of administration by humans.

Analgesic efficacy and safety of paracetamol-codeine combinations versus paracetamol alone: a systematic review

OBJECTIVES

To assess whether adding codeine to paracetamol has an additive analgesic effect; to assess the safety of paracetamol-codeine combinations versus paracetamol alone.

DESIGN

Systematic literature review with meta-analysis, methodological quality of published trials being scored by means of 13 predefined criteria.

TRIALS

24 of 29 trials that met the inclusion criteria. Models studied in the trials were postsurgical pain (21), postpartum pain (one), osteoarthritic pain (one), and experimentally induced pain (one).

INTERVENTIONS

Dosages ranged from 400 to 1000 mg paracetamol and 10 to 60 mg codeine.

MAIN OUTCOME MEASURES

The sum pain intensity difference (efficacy analysis) and the proportion of patients reporting a side effect (safety analysis).

RESULTS

Most trials were considered of good to very good quality. Only the single dose studies could be combined for analysis of analgesic efficacy. Pooled efficacy results indicated that codeine added to paracetamol provided a 5% increase in analgesia on the sum pain intensity difference. This effect was comparable to the difference in analgesic effect between codeine and placebo. The cumulative incidence of side effects with each treatment was comparable in the single dose trials. In the multidose studies a significantly higher proportion of side effects occurred with paracetamol-codeine preparations.

CONCLUSION

The difference is analgesic effect between paracetamol-codeine combinations and paracetamol alone was small but statistically significant. In the multidose studies the proportion of patients reporting a side effect was significantly higher with paracetamol-codeine combinations. For occasional pain relief a paracetamol-codeine combination might be appropriate but repeated use increases the occurrence of side effects.

Codeine disposition in human hair after single and multiple doses

OBJECTIVE

We studied the dose-proportion and time-course relationships for the incorporation of codeine into human hair after the administration of three different groups.

SUBJECTS

Male volunteers, with dark hair, were given oral codeine either as a single dose of 60 mg (n = 7) or 120 mg (n = 12) or as multiple doses of 30 mg 3 times daily for 5 days (n = 7) (450 mg total dose).

METHODS

Blood and urine were collected for various times for up to 72 h after dosing. Scalp hair was collected initially by plucking (up to 4 weeks) and later by cutting for up to 10 weeks. Plasma, urine, proximal 1 cm of hair and distal hair were each analyzed for codeine and its metabolites by positive-ion chemical ionization ion trap gas chromatography/mass spectrometry.

RESULTS

Codeine was detected in the proximal 1 cm of hair within 30 min of an oral 120-mg dose. Codeine was not detected in the distal hair segment until 3 weeks after receiving a dose of codeine. Codeine was detected in distal hair segments for at least 10 weeks at 30 pg mg-1 hair following a single 120 mg codeine dose and at 90 pg mg-1 hair following 30 mg codeine 3 times a day for 5 days. Morphine or the glucuronides of codeine or morphine were not detected in the hair specimens of these subjects.

CONCLUSION

Codeine is rapidly distributed into the germanitive elements of hair in a dose-proportional manner. A portion of the codeine remains bound as the hair grows and can be detected in distal hair for up to 10 weeks after a single dose.

Codeine self-medication in a headache patient

Self-medicating behavior for the treatment of headaches is a widespread phenomenon with costly and hazardous consequences. The case presented illustrates the ramifications of such behavior and suggests an integrated approach to the management of headaches. Biological mechanisms for the aggravation of headaches by self-medication are discussed and integrated with psychological observations. The existing epidemiologic studies of self-medication are reviewed and reveal a need for further studies, particularly in the United States.

[Reduced prescription of benzodiazepine preparations in general practice. Much to gain with little effort]

Many patients experience side effects from prolonged use of benzodiazepines and analgesics containing codeine. Therefore 66 daily users of these drugs (average dose before intervention 34 DDD/month) were encouraged to take part in a cessation experiment. They were told that a large share of their symptoms which were the indication for benzodiazepines and analgesics might be side effects from this medication. They were also given a cessation plan. Over two years the prescriptions (measured in DDD) for this group were reduced by 57%, and 26% of the patients stopped taking these medicines. A strategy is proposed for cessation of use of benzodiazepines and codeine-containing analgesics in general practice.

Preoperative ketorolac increases bleeding after tonsillectomy in children

PURPOSE

To compare the incidence of vomiting following codeine or ketorolac for tonsillectomy in children.

METHODS

We had planned to enrol 240 patients, aged 2-12 yr undergoing elective tonsillectomy into a randomized, single-blind study in University Children's Hospital. The study was terminated, after 64 patients because interim analysis of the data by a blinded non-study scientist concluded that the patients were at undue risk of excessive perioperative bleeding. After induction of anaesthesia by inhalation with N2O/halothane or with propofol 2.5-3.5 mg.kg-1 i.v., the children were administered 150 micrograms.kg-1 ondansetron and 50 micrograms.kg-1 midazolam. Maintenance of anaesthesia was with N2O and halothane in O2. Subjects were administered either 1.5 mg.kg-1 codeine im or 1 mg.kg-1 ketorolac i.v. before the commencement of surgery. Intraoperative blood loss was measured with a Baxter Medi-Vac Universal Critical Measurement Unit. Postoperative management of vomiting and pain was standardized. Vomiting was recorded for 24 hr after anaesthesia. Data were compared with ANOVA, Chi-Square analysis and Fisher Exact Test.

RESULTS

Thirty-five subjects received ketorolac. Demographic data were similar. The incidence of vomiting during the postoperative period was 31% in the codeine-group and 40% in the ketorolac-group. Intraoperative blood losses was 1.3 +/- 0.8 ml.kg-1 after codeine and 2.2 +/- 1.9 ml.kg-1 after ketorolac (mean +/- SD) P < 0.05. Five ketorolac-treated patients had bleeding which led to unscheduled admission to hospital, P < 0.05, Exact Test.

CONCLUSION

Preoperative ketorolac increases perioperative bleeding among children undergoing tonsillectomy without beneficial effects.

Pain after craniotomy. A time for reappraisal?

Pain and nausea were prospectively assessed in 52 patients following elective craniotomy. When assessed at 6-hourly intervals the mean pain scores in patients during the first 24 h for all types of craniotomy were relatively low. However, for a period of at least 2 h 18% of patients complained of excruciating pain, 37% of patients complained of severe pain, 29% of patients complained of moderate pain, 4% of patients complained of mild pain and only 12% of patients complained of no pain in the 24 h following craniotomy. The mean dose of codeine phosphate used within the study period was 123 mg (SD 81). No statistically significant differences in severity of pain or use of codeine phosphate were found when comparing patients undergoing craniotomy at different sites. For at least 2 h 37% of patients complained of severe nausea or vomiting, 35% of patients complained of moderate nausea and only 29% of patients reported no symptoms of nausea during the 24-h study period. Again, no statistically significant differences were found in the severity of emetic symptoms when comparing patients undergoing craniotomy at different sites. Contrary to standard assumptions, severe or moderate pain in the first 24 h after craniotomy is common and is poorly treated with codeine phosphate alone.

A double-blind placebo-controlled study to assess the efficacy of a compound analgesic to prevent postoperative pain following oral surgery

It has been suggested that small doses of opioid drugs given prior to surgery can reduce postoperative pain. This study was designed to compare the effectiveness of a paracetamol/codeine combination and paracetamol alone in preventing the pain following surgical removal of impacted third molar teeth under general anaesthesia. Analysis of the results showed no statistical differences between treatment groups when compared with placebo. We suggest that the opioids may not be the best drugs available to prevent the moderate to severe pain present following some oral surgery procedures.