[Comparison of the early analgesic efficacy of three different drugs after anterior cruciate ligament reconstruction]

OBJECTIVE

The pain-relieving effect and safety of compound aminopyrine phenacetin tablets, tramcontin (tramadol hydrochloride sustained-release tablets) and dolantin in the early stage of autologous tendon reconstruction of the anterior cruciate ligament (ACL) of the knee joint were compared.

METHODS

Retrospective analysis of postoperative pain and drug analgesia in 45 patients performed by the same group from November 2018 to February 2019. The random area group design was divided into two groups according to whether ACL rupture was combined with meniscal injury, group A was 24 patients with ACL reconstruction of knee joint and group B was 21 patients with ACL fracture combined with meniscus injury. The two groups were divided into three subgroups respectively according to the actual treatment of postoperative analgesic drugs received by the patients, including 4 cases of compound aminopyrine phenacetin tablets, 11 cases of oral tramcontin, 9 cases of intramuscular dolantin combined with phenergan in group A; 3 cases of compound aminopyrine phenacetin tablets, 10 cases of oral tramcontin, and 8 cases of intramuscular dolantin combined with phenergan in group B. When the early postoperative patients complain about pain and actively ask for analgesia. When the patients complained about pain after the operation and actively asked for analgesia, they were randomly given painkillers, tramcontin or dolantin combined with phenergan to relieve pain. Pain visual analogue scale (VAS) was used to evaluate pain relief and observe the occurrence of adverse reactions.

RESULTS

There were no significant dif-ferences in gender, age, body mass index, and time of hospital stay between the two groups of patients (P > 0.05). In the patients who used tramcontin and dolantin combined with phenergan to relieve pain judging by VAS score before and 1 h after taking the drug, it was found that the pain situation of the patient was significantly relieved, and the difference before and after taking the drug had statistical significance (P < 0.05). Pairwise comparisons of the three drugs applied in the two groups showed significantly greater pain relief in the dolantin combined with phenergan group than in the remaining two drugs. There was no significant difference (P > 0.05). Dolantin was prone to nausea and vomiting, but the application of phenergan was also used to reduce side effects. In terms of adverse reactions, only 1 case of nausea occurred in the tramcontin group for simple ACL reconstruction, and none of the patients in the other groups showed serious complications and allergic reactions.

CONCLUSION

Whether in cruciate ligament reconstruction alone or combined with meniscus molding or suture, compound aminopyrine phenacetin tablets, tramcontin, dolantin combined with phenergan can effectively relieve pain. Among the three drugs, dolantin caused the largest pain relief. At the same time, the combination of phenergan effectively reduced the adverse reactions, such as vomiting and nausea, and increased the drug safety.

Sedative drug prescription patterns in Danish adults from 2002 through 2021. A register-based cohort study

OBJECTIVE

Pharmacological treatment strategies for insomnia seem to vary, and there is lack of knowledge about how sedative drugs are used in a real-world setting. We investigated changes in sedative drug prescription patterns in Danish adults who initiated treatment between 2002 and 2016.

METHODS

All adults with a first-time purchase of a sedative drug registered in the Danish National Prescription Register from 2002 through 2016 were followed for five years between 2002 and 2021 for subsequent prescriptions of sedative drugs, death, or emigration. Sedative drugs were classified into anxiolytic benzodiazepines (N05BA), hypnotic benzodiazepines (N05CD), Z-drugs (N05CF), melatonin (N05CH01), promethazine (R06AD), and low-dose quetiapine (N05AH04). Analyses were stratified on time: 2002-2006, 2007-2011, and 2012-2016.

RESULTS

A total of 842,880 individuals purchased their first sedative drug between 2002 and 2016. Most of them (40.0%) initiated treatment between 2002 and 2006, whereas 29.2% initiated treatment in 2012-2016. In 2002-2006, anxiolytic benzodiazepines (46.4%), Z-drugs (42.8%), and hypnotic benzodiazepines (5.4%) were the most common first treatment. This pattern changed over time with a gradual increase in the use of melatonin, promethazine, and low-dose quetiapine, which in 2011-2016 accounted for 27% of all first treatments. During the five years from first prescription, around 27% shifted to a different sedative drug. This percentage increased slightly over time, but over time the first shift to another drug class was most often to a Z-drug or anxiolytic benzodiazepine. Few individuals (5.8%) had more than one shift and the third choice seemed randomly distributed across all other drug classes.

CONCLUSION

Sedative drug prescriptions are distributed on different drug classes, with Z-drugs and anxiolytic benzodiazepines as the most frequent first treatment, and second choice in case of shift.

Codeine and promethazine: Exploratory study on "lean" or "sizzurp" using national survey data and an online forum

BACKGROUND

The concoction known as "lean" containing codeine and promethazine, holds a prominent cultural presence and is often referenced in mass media platforms (e.g., music and social media). Surprisingly, there's a scarcity of national data characterizing the use of lean. Therefore, the current study investigated the use of lean using national survey data and online forum participant input, and focused on identifying concurrent substance use, exploring co-administration with other substances (e.g., alcohol, cannabis), and determining lean-related experiences.

METHODS

We analyzed data from the National Survey on Drug Use and Health (NSDUH) spanning 2007-2019, identifying persons who used lean (weighted N = 42,275). Additionally, we conducted a Reddit-based study to gather insights about lean consumtion (N = 192).

RESULTS

The NSDUH data indicated that lean use was most prevalent among teenagers and young adults (ages 13-21), accounting for 66% of the sample. This trend was more pronounced in male respondents (75%) compared to females. Additionally, the use was predominantly observed among Black/African American (29%), Hispanic (28%), and White (33%) populations, with these groups also reporting higher levels of concurrent alcohol and cannabis use. Similarly, findings from Reddit showed that individuals who used lean were predominantly male (67%) and exhibited elevated concurrent rates of alcohol (83%) and cannabis (46%) use in the past 30 days. Moreover, approximately 66% of respondents met criteria for severe lean use disorder, and 37% acknowledged driving under its influence.

CONCLUSION

The NSDUH data found that mostly young adult males reported consuming lean in the past twelve months, though the racial/ethnic breakdown of persons who used lean was diverse. The Reddit data found that most individuals in the sample met the criteria for a substance use disorder pertaining to their lean consumption. These findings underscore the clinical significance and necessity for further controlled research on lean.

Determination of Related Substances in Promethazine Hydrochloride and Dextromethorphan Hydrobromide in Oral Solution by RP-HPLC Method

The goal of this study is to provide a single, widely applicable high-performance liquid chromatographic (HPLC) technique for the determination of related substances in multicomponent oral solution of promethazine hydrochloride and dextromethorphan hydrobromide. For the assessment of impurities of promethazine hydrochloride and dextromethorphan hydrobromide in oral solution, a unique, sensitive, quick, stability-indicating gradient HPLC technique has been created. For chromatographic separation, an Agilent Eclipse XDB-C18, 250 mm × 4.6 mm, 5 μm column was used with a buffered mobile phase consisting of a mixture of potassium dihydrogen phosphate pH 3.0:acetonitrile (80:20) v/v as mobile phase A and potassium dihydrogen phosphate pH 3.0:acetonitrile:methanol (10:10:80) v/v/v as mobile phase B. The separation was performed at a flow rate of 1.2 mL/min and a detection wavelength of 224 nm. The temperature of the column oven was regulated at 40°C. With good sensitivity and resolution, all compounds were effectively separated on a reverse-phase HPLC column. Acid, base, photolytic, thermal, oxidative and humidity stress conditions significantly degraded dextromethorphan hydrobromide and promethazine hydrochloride. The developed technique was validated according to the criteria of the International Conference on Harmonization for all validation parameters such as specificity, accuracy, linearity, precision, the limit of detection, the limit of quantitation and robustness.

Determination of promethazine in forensic samples using multi-walled carbon nanotube-gold nanoparticle electrochemical sensor

An electrochemical sensor was developed based on a glassy carbon electrode (GCE) modified with multi-walled carbon nanotubes (MWCNTs) and gold nanoparticles (AuNPs) for the determination of promethazine (PMZ) in 'purple drank', pharmaceutical formulations, and synthetic saliva. The oxidation of PMZ at the modified electrode occurred at a higher cathodic potential and produced a higher sensitivity compared to the unmodified GCE. The morphology of the modified electrode was characterized using field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), and transmission electron microscopy (TEM). The presence of MWCNTs and AuNPs was confirmed. The optimized parameters included the concentration and pH of the supporting electrolyte, amount of modifiers used to fabricate the electrode, deposition potential, and time. Using these optimized conditions, the method has a linear range from 0.5 to 100 μmol L-1, with a R2 value of 0.9991. The limit of detection (3SDblank/slope) was 0.13 μmol L-1. The proposed electrochemical sensor was successfully applied for the determination of PMZ in 'purple drank', pharmaceutical formulations, and spiked synthetic saliva samples. The results obtained from this sensor were in statistical agreement with the values obtained using the reference gas chromatography-flame ionization method.

Sedative drug-use in Denmark, 2000 to 2019: a nationwide drug utilization study

AIM

To describe trends in and characteristics of sedative drug use from 2000 through 2019 in relation to the introduction of central regulations and new drugs.

METHODS

In this descriptive study, we used individual prescription data on the entire Danish population from the Danish National Prescription Registry to calculate yearly incidence and prevalence of use of benzodiazepines, benzodiazepine-related drugs (Z-drugs), melatonin, olanzapine, low-dose quetiapine, mianserin/mirtazapine, pregabalin, and promethazine from 2000 through 2019. From the Danish National Patient Registry, we obtained data on drug users' psychiatric and somatic comorbidity.

RESULTS

The use of benzodiazepines and Z-drugs declined gradually from 2000 through 2019, whereas the newer alternatives, melatonin, low-dose quetiapine, pregabalin and promethazine, increased in use, while the use of olanzapine and mianserin/mirtazapine was relatively stable. This development was seen in both men and women and across all age groups except for hypnotic benzodiazepines which showed a steep increase in the oldest age group from 2010. For all sedative drugs depression, anxiety, alcohol and misuse disorder, pain and cancer were the most prevalent comorbidities. During our study period, the number of individuals without any of the selected diagnoses increased.

CONCLUSION

In Denmark different central regulations have influenced prescription practice toward more restrictive use of Z-drugs and benzodiazepines, except for hypnotic benzodiazepine prescriptions increased after the introduction of special palliative care. An increase in use of newer sedative drugs, however, indicates that the regulations do not remove the need for sedative drugs in the population.

A novel physiologically based pharmacokinetic model of rectal absorption, evaluated and verified using clinical data on 10 rectally administered drugs

We present a physiologically based pharmacokinetic (PBPK) model simulating systemic drug concentrations following administration to the human rectum. Rectum physiology is parameterized based on literature data. The model utilizes in vitro release (IVRT) profiles from which drug mass transfer through the rectal fluid and tissue and into the systemic circulation are predicted. Due to a lack of data, rectal fluid and tissue absorption parameters are predicted either from colon absorption, with modifications relevant to rectal physiology, or optimized. The PBPK model is evaluated by simulating 29 clinical studies for 10 drugs. For 8 drugs (diazepam, diclofenac, indomethacin, naproxen, paracetamol, pentobarbital, phenobarbital and theophylline) the bias (average fold error, AFE) and precision (absolute average fold error, AAFE) of Cmax, AUC0-t and AUC0-inf simulations range from 0.87 to 2.22, indicating good agreement with observed values. For prochlorperazine and promethazine, the AFEs and AAFEs of Cmax predictions are 1.30 and 2.52, respectively. TheAUC0-t and AUC0-inf are overpredicted for both compounds(AFEs and AAFEs from 2.66 to 4.90). This results from a lack of reliable elimination data for prochlorperazine and the relevance of the IVRT profiles used in the promethazine model. The model paves the way for more mechanistic rectal drug absorption studies and virtual bioequivalence methods for rectal drug products.

CdO Decorated with Polypyrrole Nanotube Heterostructure: Potent Electrocatalyst for the Detection of Antihistamine Drug Promethazine Hydrochloride in Environmental Samples

In the realm of electrochemical sensor application, the development and fabrication of semiconducting metal oxides with the integration of conducting polymers for the trace-level detection of pharmaceutical medicines garnered considerable interest. Herein, we reported facile cadmium oxide decorated with polypyrrole nanotubes fabricated on a glassy carbon electrode (CdO@PPy/GCE) for efficient determination of antihistamine drug promethazine hydrochloride (PMH). The as-synthesized CdO@PPy composite was characterized by various analytical tools like X-ray powder diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. Furthermore, the electrocatalytic activity of the modified electrode for PMH detection was examined by voltammetry and amperometric methods, and the modified electrode exhibited lower charge transfer resistance compared to the bare GCE. Under the optimized condition, the fabricated electrode shows a wide linear range (50-550 μM), better sensitivity (0.13 μAμM-1 cm-2), low detection limit (10.83 nM) (S/N = 3), and excellent selectivity and reproducibility toward PMH detection. Moreover, the modified GCE depicted eminent practical ability for PMH detection in lake water and pharmaceutical tablets.

[Determination of 4 chlorpromazine and promethazine and their metabolites in swine tissues by liquid chromatography-tandem mass spectrometry with isotope internal standard dilution technique]

OBJECTIVE

To establish a rapid, accurate and sensitive method by liquid chromatography-tandem mass spectrometry with isotope internal standard dilution technique for the determination of chlorpromazine and promethazine and their metabolites in swine tissues.

METHODS

The swine tissues sample was extracted with acetonitrile and purified on MCX cartridge. The liquid chromatography separation was performed on an ACQUITY UFLC® HSS T3(100 mm×2.1 mm, 1.8 μm) with a linear gradient elution program of 0.1%(V/V) fomic acid-acetonitrile and 0.1%(V/V) formic acid-water solution as the mobile phase. The analytes were analyzed using ESI operating in the positive multiple reaction monitoring(MRM) mode.

RESULTS

The limits of quantitation(LOQs) and limits of detection(LODs) for the target objects were 0.12-0.51 μg/kg and 0.04-0.17 μg/kg, respectively. The calibration curves were linear in range of 0.1-20.0 μg/L for chlorpromazine and promethazine, and 0.5-100.0 μg/L for their metabolites(chlorpromazine sulfoxide and isopropyl sulfoxide). The recoveries were between 90.8%-106.0%, and the relative standard deviations(RSDs) were between 1.9%-6.2%(n=6).

CONCLUSION

The method is highly sensitive and accurate, and is suitable for the analysis of chlorpromazine and promethazine and their metabolites(chlorpromazine sulfoxide and isopropyl sulfoxide) in swine tissues.

Use of tracking drugs for the search of intra-hospital adverse reactions: a pharmacovigilance study

OBJECTIVE

To estimate the incidence of potential in-hospital adverse reactions  with the use of alert drugs in a general hospital in southern Brazil. Method: Cross-sectional study, carried out in a hospital in southern Brazil. The  electronic medical records (TASY®) of patients hospitalized between January  and August 2020, who were prescribed one of the drugs earmarked for  tracking adverse drug reactions, were evaluated: the drugs included  flumazenil, fexofenadine hydrochloride, naloxone, promethazine, diphenhydramine and loperamide.

RESULTS

A total of 13,476 medical records were reviewed and 204 (1.5%)  were included in the study in which tracker use was indicated in the management of adverse drug reactions. In this study a total of 18 different signs or symptoms were found in medical records, with  pruritus/hyperemia/urticaria being the most reported symptoms (n = 76).  Among the drug classes that caused most adverse drug reactions, opioids were  the most mentioned (n = 44). It should be noted that in 49 medical  records the information on which drug caused the adverse events was not  reported. Regarding the cause of hospitalization of patients who used  creening drugs, cancer was the most frequent (n = 37).

CONCLUSIONS

This study indicates that the use of trackers can be a tool to  estimate the occurrence of adverse drug reactions and to establish adverse  events related to the use of medications, which should be reported to the  pharmacovigilance service, with a view to patient safety.

[Sedating antihistamines - risk of severe intoxication]

Overdoses with the sedating antihistamines alimemazine, hydroxyzine, promethazine and propiomazine have received attention in recent years in Sweden. The Poisons Information Center has noted an increase in calls regarding intoxications, and the National Board of Forensic Medicine has concluded that these substances have directly contributed to a large number of poisoning deaths. When prescribing alimemazine, hydroxyzine, promethazine and propiomazine, their pharmacological properties, such as antihistaminergic and anticholinergic effects, and their anti-arrhythmic potential must be considered. Furthermore, it is important to also consider the risks of severe intoxication in case of overdose. The lowest possible amount should be prescribed. Special attention is required when prescribing alimemazine oral solution.

Study protocol for a randomised controlled trial of haloperidol plus promethazine plus chlorpromazine versus haloperidol plus promethazine for rapid tranquilisation for agitated psychiatric patients in the emergency setting (TREC-Lebanon)

Background: Agitated and aggressive behaviours are common in the psychiatric setting and rapid tranquilisation is sometimes unavoidable. A survey of Lebanese practice has shown that an intramuscular haloperidol, promethazine and chlorpromazine combination is a preferred form of treatment but there are no randomised trials of this triple therapy. Methods: This is a pragmatic randomised trial. Setting - the psychiatric wards of the Psychiatric Hospital of the Cross, Jal Eddib, Lebanon. Participants - any adult patient in the hospital who displays an aggressive episode for whom rapid tranquilisation is unavoidable, who has not been randomised before, for whom there are no known contraindications. Randomisation - stratified (by ward) randomisation and concealed in closed opaque envelope by independent parties. Procedure - if the clinical situation arises requiring rapid tranquilisation, medical residents overseeing the patient will open a TREC-Lebanon envelope in which will be notification of which group of treatments should be preferred [Haloperidol + Promethazine + Chlorpromazine (HPC) or Haloperidol + Promethazine (HP)], along with forms for primary, secondary and serious adverse effects. Treatment is not given blindly. Outcome - primary outcome is calm or tranquil at 20 minutes post intervention. Secondary outcomes are calm/tranquil at 40, 60 and 120 minutes post intervention, asleep, adverse effects, use of straitjacket and leaving the ward. Follow-up will be up to two weeks post randomisation. Discussion: Findings from this study will compare the HPC versus HP combination used in Lebanon's psychiatry emergency routine practice. Trial registration: ClinicalTrials.gov NCT03639558. Registration date, August 21, 2018.

This Month in AJP

The following highlights summarize research articles that are published in the current issue of The American Journal of Pathology.

Hydroxylation in vitro of pharmacologically active phenothiazine derivatives

The hydroxylation of promazine, chlorpromazine, chlorproethazine, triflu-promazine and promethazine by a rat liver preparation is described. It is concluded that promazine is converted to 3-hydroxypromazine by this system.

How the FDA can overturn Wyeth v. Levine

In Wyeth v. Levine, the Supreme Court held that an FDA-approved drug label did not preempt state tort law. Although the Supreme Court did not defer to the FDA's position, language in the opinion, and Breyer's concurring opinion, suggest that the FDA may be able to abrogate Wyeth v. Levine using the administrative law doctrine originally announced in Chevron v. Natural Resources Defense Council. That is, the FDA may claim deference to its position in a future case involving the same legal questions. This Note explains how Wyeth impacts the Chevron doctrine and identifies how the FDA assertion that drug labels preempt state law may win in a future case.

Different job demands of nightshifts in hospitals

It is now recognized that the effects of nightwork result jointly from desynchronization of circadian rhythms and from the job content. In scheduling nightwork, use should be made of the shift systems most compatible with the biological rhythms and social patterns of the workers concerned, and specific measures should be implemented to reduce demands on nightworkers. Job content is of particular importance in the hospital sector, where demands vary greatly from one department to another. Above all, the tasks accomplished by those on nightshift differ markedly from those of daytime workers: nightwork is limited to scheduled health care jobs that cannot be deferred until the morning, and to management of incidents. Yet staffing levels at night are reduced. Certain daytime resources are lacking at night, and the working conditions, generally defined with reference to the activities of daytime personnel fail to take into account the specific features of nightwork which are largely ignored by the management. On the basis of various studies conducted in French hospitals (extensive questionnaire surveys, ergonomic analyses in different departments), these features of nightwork and the corresponding need for appropriate responses, in terms of shift systems and job content, are reviewed and discussed.

Central effects produced by injection of 48/80 into the cerebral ventricles of mice

Injections of 20 to 30 mug. of 48/80 into the cerebral ventricular spaces of mice produced a condition of motor excitement termed "delirium ambulatorium." This condition was aggravated by previous intraperitoneal injection of tranquillizers, atropine, and promethazine, not affected by previous injection of mepyramine and abolished by a previous injection of pentobarbitone. When an intraperitoneal injection of strychnine was followed by an intraventricular injection of 48/80, the strychnine convulsions became more violent, but the pattern of delirium ambulatorium was not produced.

Influence of promethazine on circulatory response to endotoxin in dogs

Histamine has been implicated as an intermediary in the mechanism of experimental endotoxin shock. The effect of pretreatment with an antihistaminic drug, promethazine hydrochloride (PMZ), on the hemodynamic response to E. coli endotoxin was studied in a group of 13 anesthetized dogs. Results were compared with the characteristic effects of endotoxin obtained in six control animals. Parameters that were measured and evaluated for possible effects of pretreatment were as follows: systemic artery, pulmonary artery, and portal vein pressures; cardiac output; heart rate; and calculated systemic and pulmonary resistances. In six animals that received doses of PMZ ranging from 1 to 9 mg/kg, the responses to endotoxin were not significantly different from those in the control group. However, in a group of seven dogs pretreated with a standard dose of 20 mg/kg PMZ, a modified response was demonstrated consisting of significant reduction in the magnitude of early systemic hypotension and portal venous hypertension. Pulmonary hypertension was augmented. The results are consistent with the interpretation that certain circulatory effects of endotoxin are mediated through histamine and that these are partially amenable to selective inhibition by an adequate dose of an antihistaminic agent such as PMZ.

Drug inhibition of circulatory response to endotoxin in dogs

The effect of combined pretreatment with a drug that inhibits the synthesis of serotonin, alpha-methyl 3,4-dihydroxyphenylalanine, and an antihistamine, promethazine hydrochloride, on the hemodynamic response to E. coli endotoxin was studied in a group of six dogs. Compared with the characteristic endotoxin response obtained in six control experiments, pretreated animals given endotoxin demonstrated significantly less elevation of pulmonary artery (PAP) and portal venous (PVP) pressures, and less striking fall in systemic arterial pressure (SAP) and cardiac output. Considering the average maximum changes alone, expressed as percentage of preendotoxin base-line values, in the control vs. pretreated groups, respectively, results were as follows: SAP, 36 vs. 84%; cardiac output, 31 vs. 66%; PAP, 162 vs. 118%; PVP, 338 vs. 186%. This investigation lends additional support to the concept that many of the cardiovascular effects of endotoxin are mediated through the release of vasoactive agents such as histamine and serotonin.

Antagonism of apomorphine-induced pecking in pigeons

Central nervous system stimulants, tranquillizers and other central nervous system depressants, antiemetics, antihistamine drugs and autonomic blocking agents were examined for their ability to prevent the pecking response in pigeons induced by apomorphine (250 mug/kg intramuscularly). Reduction in the proportion of positive responses or significant increase in the latent period of pecking were taken as the criterion of effectiveness. Protection was afforded by caffeine, lysergic acid diethylamide, morphine, rauwolscine, triflupromazine and yohimbine. In addition, a significant increase in latent period was produced by artane, pentobarbitone, benactyzine, 2-bromolysergic acid diethylamide, cyclizine, diphenhydramine, ergotoxine, hyoscine, promethazine, 5-(2-chloroethyl)-4-methylthiazole and trimethobenzamide. Most of these drugs influenced the pecking and emetic responses to apomorphine in an identical manner. It is possible that identical receptors may be concerned with apomorphine pecking (in pigeons) and emesis (in other species).

On the nature of the chemical mediators involved in anaphylactic reactions in mice

The effects of mepyramine, promethazine, chlorpromazine and lysergic acid diethylamide have been compared on the capillary permeability changes of the skin, produced by histamine, by 5-hydroxytryptamine and by passive cutaneous anaphylaxis in mice. Promethazine, mepyramine and chlorpromazine can inhibit, in decreasing order of activity, the effect of histamine, whilst lysergic acid diethylamide is inactive. Lysergic acid diethylamide and chlorpromazine are equally potent inhibitors of the action of 5-hydroxytryptamine on the peripheral vascular bed, whilst mepyramine is inactive. Promethazine has intermediate activity. Passive cutaneous anaphylaxis is strongly inhibited by chlorpromazine and by promethazine. Mepyramine and lysergic acid diethylamide, each injected alone, affect only weakly the anaphylactic reaction. However, passive cutaneous anaphylaxis is almost completely abolished by the simultaneous injection of the two last antagonists. It is suggested that the anaphylactic reaction in mice is the result of simultaneous release of both mediators, histamine and 5-hydroxytryptamine, each of them strengthening the effect of the other.

Conscious sedation with combined hypnotic agents for implantation of implantable cardioverter-defibrillators

OBJECTIVES

The objective of this study was to evaluate the feasibility, safety and efficacy of placing implantable cardioverter-defibrillators (ICDs) in the electrophysiology laboratory using conscious sedation with combined hypnotic agents and deep sedation with etomidate.

BACKGROUND

Implantable cardioverter-defibrillators with transvenous leads permit the use of simplified implantation techniques similar to those used for the insertion of permanent pacemakers. However, implantation of ICDs without general anesthesia has thus far gained limited acceptance.

METHODS

In 162 patients, conscious sedation during ICD placement was achieved with combined intravenous midazolam, morphine and promethazine (Phenergan). Intravenous etomidate was administered to induce deep sedation for defibrillation threshold testing. First-time implantations were in the prepectoral position (n = 142), but some patients with preexisting devices received abdominal implants (n = 20). The results were compared with those of concurrent patients (n = 56) who received prepectoral implants under propofol anesthesia administered by an attending anesthesiologist.

RESULTS

The anesthetic protocol was implemented without major intraoperative complications. During deep sedation with etomidate, episodes of apnea, hypoxia or arterial hypotension requiring therapeutic intervention did not occur. During a mean (+/-SD) follow-up period of 257 +/- 140 days (median 227, range 14 to 482), there were, among the 162 patients, a total of two nonsudden cardiac deaths-one 71 days and the other 157 days after the operation. There were two nonsudden deaths in the concurrent control subjects (n = 56)-one 13 days and the other 110 days after the operation.

CONCLUSIONS

Implantation of ICDs under conscious sedation with combined hypnotic agents and deep sedation with etomidate is a safe and effective procedure with low perioperative morbidity and low long-term complication rates.

THE EFFECT OF SOME PHENOTHIAZINE TRANQUILLIZERS ON THE OESTROUS CYCLE OF ALBINO MICE

The effects of reserpine and of nine phenothiazine compounds on the oestrous cycle of albino mice were tested. With the exception of promethazine (which is not a tranquillizer) all the phenothiazine compounds and reserpine prolonged the oestrous cycle. The mechanism by which these tranquillizers interfere with the oestrous cycle is discussed.

THE EFFECTS OF DRUGS ON THE UPTAKE OF AMINES BY MAST CELLS

Neoplastic mast cells, taken from an ascitic tumour in mice and incubated in vitro, took up (14)C-labelled 5-hydroxytryptamine and histamine from the medium. Uptake during the first hour gave an approximate measure of the initial rate. The amount of each amine taken up in this time was determined by bioassay and by radioactivity, the two methods giving similar results. The curves obtained by plotting initial rate of uptake against concentration in the medium suggested that the uptake of 5-hydroxytryptamine was by an active process and also by diffusion, whereas uptake of histamine was by diffusion only. The cells also took up (14)C-labelled (+/-)-noradrenaline and tryptamine, apparently by diffusion. The active uptake of 5-hydroxytryptamine was inhibited by lowering the temperature to 25 degrees C or by increasing the pH to 8.9, procedures which had little effect on histamine uptake. The effects of cocaine, imipramine, chlorpromazine, mepyramine, promethazine, phenoxybenzamine, lysergic acid diethylamide, bromolysergic acid diethylamide, methysergide, guanethidine, dichloroisoprenaline and pronethalol on the uptake of amines were examined. In general, any antagonist which inhibited uptake of 5-hydroxytryptamine had little effect on uptake of histamine, and vice versa. Possible ways in which these antagonists produce their effects on amine uptake are discussed. A high concentration of 5-hydroxytryptamine, of tryptamine or of noradrenaline inhibited uptake of histamine, but only tryptamine decreased uptake of 5-hydroxytryptamine. These results, together with those from experiments with antagonists, suggest that there are specific binding sites for 5-hydroxtryptamine in these cells.

PRODUCTION OF INFLAMMATORY CHANGES IN THE MICROCIRCULATION BY CATIONIC PROTEINS EXTRACTED FROM LYSOSOMES

Lysosomal granules of rabbit exudate polymorphonuclear (PMN) leucocytes were isolated and then lysed by freezing-thawing. Topical application of this material to rat and rabbit mesentery produced sticking and emigration of leucocytes, stasis of blood flow, and petechial hemorrhage. The granule-free, supernatant fraction of the homogenized leucocytes failed to produce any of these reactions. Cationic proteins extracted from these granules by weak acid and precipitated by ethanol at concentrations of 20 and 45 per cent, were also tested on heterologous, homologous, and autologous mesenteric vessels. The 20 per cent ethanol-precipitated fraction produced all of the aforementioned injury reactions, whereas the 45 per cent fraction was inactive. The intensity of inflammatory changes produced by the active cationic protein fraction was greater than that produced by lysed whole granules. Both the 20 per cent and 45 per cent ethanol fractions of cationic protein induced clumping of rabbit platelets, in vitro. The 20 per cent ethanol fraction also caused a slight acceleration in rate of swelling of isolated rabbit liver mitochondria. The active material proved to be non-pyrogenic in rabbits. This material exhibited no kinin-like effects when tested on isolated smooth muscle preparations (rabbit aorta and guinea pig ileum). In the rat, the protein produced a transient vasodepression which was inhibited by pretreatment of the animal with an antihistamine. Ultraviolet absorption data and ribose assays showed that the 20 per cent ethanol fraction contained only 4 per cent or less of ribonucleic acid. Upon electrophoresis in starch gel, using acid buffer, this fraction separated into at least three major components which migrated towards the cathode. Precipitation of one of the slowly migrating components by titration of the fraction to pH 10.5 greatly increased the inflammatory activity of the material. The inflammatory basic protein fraction was essentially devoid of acid phosphatase, beta glucuronidase, acid ribonuclease, lysozyme, and catalase activity. The non-inflammatory basic protein fraction contained appreciable quantities of acid ribonuclease and lysozyme. The foregoing data demonstrate that certain of the cationic proteins present in lysosomes of rabbit exudate PMN leucocytes can reproduce one of the cardinal features of the inflammatory response; namely, adhesion and emigration of leucocytes in the microcirculation. These findings offer fresh support for the role of lysosomes in the pathogenesis of tissue injury, and may help to account for the propagation of leucocyte emigration to peak numbers during inflammatory reactions.