Pharmaceutics for the anaesthetist

Allergic reactions to propofol in adult patients with egg or soybean allergy: a retrospective cohort study from a large database of a single institute

BACKGROUND

In recent years, many reports have indicated that propofol is safe to administer to patients with egg/soybean allergy in Western countries. Egg allergy is more frequent in Asia, but there are limited reports regarding allergic reactions to propofol use among adults. This study aimed to determine whether propofol causes allergic reactions in patients with egg/soybean allergy.

METHODS

Adult patients who underwent surgery involving anesthesiologists from 2018 to 2021 were included. In all patients, we reviewed food allergy information in their electronic medical record and extracted anesthetics. Patients with egg/soybean allergy were subdivided into two groups on the basis of intraoperative use of propofol. We evaluated each group for allergic reactions within 24 h after the induction of anesthesia. The primary outcome was a relative risk of allergic reactions after propofol use for patients with egg/soybean allergy.

RESULTS

In total, 22,111 patients with 28,710 anesthesia records were identified. Among patients with egg/soybean allergy, 173 (0.8%) patients and 237 (0.8%) anesthesia records were included in the study. Among the records of egg-/soybean-allergic patients, 151 were administered propofol, and 86 were not. The relative risk of allergic reactions after propofol use for patients with egg/soybean allergy was 1.14 (95% confidence interval, 0.10-12.4; p = 0.74).

CONCLUSION

The use of propofol in patients with egg/soybean allergy does not significantly increase the relative risk of allergic reactions. Therefore, anesthesiologists can appropriately determine the indication for propofol, even in patients with egg/soybean allergy.

TRIAL REGISTRATION

UMIN-CTN, UMIN000049321 registered 26 October 2022 - retrospectively registered, https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000056167.

Multiple drug allergies: Recommendations for perioperative management

Life-threatening hypersensitivity reactions are more likely to occur in patients with a history of allergy, atopy, or asthma. Hence, in a patient who presented with a history of multiple drug allergies (MDA), an allergological assessment should be performed prior to surgical procedure. Drug allergies, being one of the causes of catastrophic events occurring in the perioperative period, are of major concern to anesthesiologists. Neuromuscular blocking agents are regularly used during anesthesia and are one of the most common causes of perioperative anaphylaxis. They are estimated to be responsible for 50%-70% of perioperative hypersensitivity reactions. Antibiotics and latex represent the next two groups of drug allergy. Allergic reactions to propofol are rare with an incidence of 1:60,000 exposures. Although intraoperative drug anaphylaxis is rare, it contributes to 4.3% of deaths occurring during general anesthesia. These recommendations discuss pathophysiology of MDA, preoperative evaluation, and anesthesia considerations as well as the prevention and management of allergic reactions in anesthetized patients with a history of MDA.

Growth of Staphylococcus epidermidis in Anaesthetic Resuscitative Drugs: Implications for Potential Contamination

This controlled laboratory study investigated the survival of Staphylococcus epidermidis (S. epidermidis) over a 24 hour period in four commonly drawn-up anaesthetic resuscitative drugs: suxamethonium, atropine, metaraminol and ephedrine. These drugs were prepared in typical therapeutic concentrations and then inoculated with S. epidermidis. Samples of the inoculated drug preparations were cultured on horse blood agar plates at 0, 2, 6, 12 and 24 hourly intervals and incubated for 24 hours.

Colony counts were performed at the end of the incubation period. Suxamethonium, atropine and metaraminol all showed an inhibitory effect on colony counts within the first six hours. There was a more gradual decline of colony counts over a 24 hour period in the ephedrine solution. This decline was similar to that occurring in the normal saline. It is concluded that suxamethonium, atropine and metaraminol do not support the survival of the common skin contaminant, S. epidermidis over a 24 hour period.

The effect of sulfite and chronic restraint stress on brain lipid peroxidation and anti-oxidant enzyme activities

Sulfites are used as anti-microbial and anti-oxidant agents in a variety of drugs, and function as a preservative in many food preparations. In addition to these effects, sulfites oxidize to sulfite radicals initiating lipid peroxidation. The objective of our study was to investigate the effect of restraint stress and sulfite on brain lipid peroxidation and anti-oxidant enzyme activities. Forty male Wistar rats, aged three months, were randomized to one of the following groups: control, restraint stress, sulfite-treated and restraint stress-/sulfite-treated. Chronic restraint stress was applied for 21 days (1 h/day) and sodium metabisulfite (520 mg/kg per day) was given by gavage for the same period. Lipid peroxidation was measured using the thiobarbituric acid (TBA) fluorometric assay. TBA-reactive substances (TBARS) were found increased in all treatment groups when compared to the control group. Spectrophotometric measurement of copper/zinc superoxide dismutase (Cu/Zn SOD) and catalase (CAT) revealed decreased enzyme activities in rats exposed to restraint stress compared to control and sulfite-treated rats. GSH-Px activities were significantly decreased in the restraint stress and sulfite-treated rats compared with the control rats. GSH-Px activity measured in restraint stress-/sulfite-treated rats was significantly lower than in the other groups. The presented data confirms the pro-oxidant activity of restraint stress and establishes that decreased anti-oxidant enzyme activities in restraint stress-treated rats enhances brain lipid peroxidation caused via the ingestion of sulfites.

No evidence for contraindications to the use of propofol in adults allergic to egg, soy or peanut†

BACKGROUND

Propofol is thought to be a potential cause of allergic reactions in patients allergic to egg, soy or peanut, since current formulations contain an emulsion that includes egg lecithin and soybean oil. However, other than six case reports lacking in confirmatory evidence of an allergic reaction, there is no evidence linking the two types of allergies. The aim of this study was to examine the frequency of propofol allergy and to investigate if patients with specific immunoglobulin E (IgE) to egg, soy or peanut tolerated propofol.

METHODS

Study A examined the frequency of propofol allergy in 273 patients systematically investigated for suspected perioperative allergic reactions. Of these, 153 had been exposed to propofol and underwent skin tests and intravenous provocation. Study B retrospectively investigated propofol exposure and tolerance in 520 adult patients with a positive specific IgE to egg, soy or peanut.

RESULTS

Four of the 153 propofol-exposed patients (2.6%) investigated in study A were diagnosed with propofol allergy. Of these, three tested positive only on intravenous provocation. None of the four had allergic symptoms when eating egg, soy or peanut and none had detectable levels of specific IgE to egg or soy in their serum. In study B we found no signs of allergic reactions towards propofol in 171 retrieved anaesthetic charts from 99 patients with specific IgE to egg, soy or peanut.

CONCLUSION

No connection between allergy to propofol and allergy to egg, soy or peanut was found. The present practice of choosing alternatives to propofol in patients with this kind of food allergy is not evidence based and should be reconsidered.

A case of propofol-induced oropharyngeal angioedema and bronchospasm

Propofol (2,6-diisopropylphenol) is an ultrashort-acting sedative agent with sedative and amnestic effects that is used not only for anesthesia but also for sedation during minor outpatient procedures and endoscopic examinations. Rare cases of anaphylaxis following propofol administration have been reported in the medical literature. Documentation of anaphylaxis is often lacking because the cause and effect relationship is often hard to prove. Only a minority of patients get referred for allergy testing to confirm the offending drug. Here we report a 74-year-old woman who had an anaphylactic reaction with severe oropharyngeal edema and bronchospasm for a few minutes after receiving propofol during endoscopic examination. An allergy skin test was positive for both propofol and soybean. Soybean in the intralipid is one component of propofol, and we concluded that this anaphylaxis was caused by soybean.

Sodium metabisulfite induces lipid peroxidation and apoptosis in rat gastric tissue

Sodium metabisulfite (Na 2S2O5) is used as an antioxidant and antimicrobial agent in a variety of drugs and functions as a preservative in many food preparations. This study was performed to elucidate the dose-dependent effects of sodium metabisulfite ingestion on rat gastric tissue apoptotic changes and lipid peroxidation. Forty male wistar rats, aged 3 months were used. They were randomly divided into four groups: control (C), the group treated with Na2S2O5 (10 mg/kg; S1), the group treated with Na2S2O5 (100 mg/kg; S2), the group treated with Na2S2O5 (260 mg/kg; S3). Na 2S2O5 was given by intragastric intubation for 35 days. In the S2 and S3 groups, malondialdehyde (MDA) levels increased markedly when compared with the control group. High doses of sulfite administration elevated number of apoptotic cells both in mucosa and submucosa layers of stomach in parallel with increased MDA levels. These results suggest that sodium metabisulfite increased lipid peroxidation and thus number of apoptotic cells on gastric tissue in dose-dependent manner.

Discovery, development, and clinical application of sugammadex sodium, a selective relaxant binding agent

Neuromuscular blockade, induced by neuromuscular blocking agents, has allowed prescribed immobility, improved surgical exposure, optimal airway management conditions, and facilitated mechanical ventilation. However, termination of the effects of neuromuscular blocking agents has, until now, remained limited. A novel cyclodextrin encapsulation process offers improved termination of the paralytic effects of aminosteroidal non-depolarizing neuromuscular blocking agents. Sugammadex sodium is the first in a new class of drug called selective relaxant binding agents. Currently, in clinical trials, sugammadex, a modified gamma cyclodextrin, has shown consistent and rapid termination of neuromuscular blockade with few side effects. The pharmacology of cyclodextrins in general and sugammadex in particular, together with the results of current clinical research are reviewed. The ability of sugammadex to terminate the action of neuromuscular blocking agents by direct encapsulation is compared to the indirect competitive antagonism of their effects by cholinesterase inhibitors. Also discussed are the clinical implications that extend beyond fast, effective reversal, including numerous potential perioperative benefits.

The effects of intrathecal administration of betamethasone over the dogs' spinal cord and meninges

PURPOSE

To determinate the potential clinical and histological changes due the injection of betamethasone, when administered into the canine intrathecal space.

METHODS

Twenty one animals were included in a random and blind manner in the study. After general anesthesia, intrathecal puncture was performed and 1 ml of the random solution was injected. The G1 dogs received 0.9% saline solution, the G2 dogs received 1.75 mg betamethasone and the G3 dogs received 3.5 mg of betamethasone. The animals were clinically evaluated for 21 days and then sacrificed. The lumbar and sacral portions of the spinal cord were removed for light microscopy histological analyses.

RESULTS

No clinical changes were observed in any of the animals included in this study. No histological changes were observed in G1 animals. Inflammatory infiltration was observed in two dogs, one in G2, another in G3. Hemorrhage and necrosis were also seen in the G2 dog which inflammatory infiltration was detected. In other two dogs, one from G2 and another from G3, there was discreet fibrosis and thickness of the arachnoid layer which was focal in one and diffuse in the other.

CONCLUSION

Intrathecal administration of betamethasone caused histological changes in the spinal cord and meninges in some of the dogs involved in this study.

Allosteric positive interaction of thymol with the GABAA receptor in primary cultures of mouse cortical neurons

Thymol is a naturally occurring phenolic monoterpene known for its anti-microbial and anti-oxidant properties. It is used in dental practice and in anaesthetic halothane preparations. Recent studies have reported enhanced GABA(A) receptor-operated chloride channel activity and increased binding affinity of [(3)H]flunitrazepam in the presence of thymol. In the present work, we more closely examined the pharmacological action of thymol on the native GABA(A) receptor by using primary cultures of cortical neurons. Thymol enhanced GABA-induced (5 microM) chloride influx at concentrations lower than those exhibiting direct activity in the absence of GABA (EC(50) = 12 microM and 135 microM, respectively). This direct effect was inhibited by competitive and non-competitive GABA(A) receptor antagonists. Thymol increased [(3)H]flunitrazepam binding (EC(50) = 131 microM) and showed a tendency to increase [(3)H]muscimol binding. These results confirm that thymol is a positive allosteric modulator of the GABA(A) receptor. The thymol structural analogues menthol and cymene, which lack an aromatic ring or a hydroxyl group, did not affect [(3)H]flunitrazepam binding. Using a pharmacophoric model that includes a hydrogen bond donor group as well as an aromatic ring with two aliphatic substituents, we propose to demonstrate the molecular essential features of these compounds to interact with GABA(A) receptors. Thymol (0-1 mM) did not affect cellular viability.

The prooxidant effect of sodium metabisulfite in rat liver and kidney

Sodium metabisulfite (Na2S2O5) is used as an antioxidant and antimicrobial agent in a variety of drugs and functions as a preservative in many food preparations. In addition to their antioxidant activity, sulfites oxidize to sulfite radicals (SO3-) initiating lipid peroxidation. This study was performed to elucidate the effect of subchronic Na2S2O5 (520 mg/kg/day) ingestion on hepatic and renal antioxidant enzyme activities and lipid peroxidation in albino rats. The antioxidant effect of l-carnitine was also tested in rats treated with Na2S2O5. Plasma uric acid levels were monitored in all rats included in the study. Malondialdehyde (MDA) levels significantly increased in Na2S2O5 treated rats vs. controls, with kidney values of 2.21+/-0.21 vs. 1.22+/-0.35 and liver values of 79.85+/-19.5 vs. 31.36+/-5.0 nmol/mg protein, respectively. Selenium-glutathione peroxidase (GPx) activity was significantly increased in Na2S2O5 treated rats vs. controls, with kidney values of 38.22+/-2.21 vs. 8.09+/-0.76 and liver values of 31.11+/-6.37 vs. 11.70+/-1.02 U/g protein, respectively. Sodium metabisulfite treatment increased plasma uric acid levels in rats that were included in the study. No protective effect of l-carnitine was observed against lipid peroxidation in both liver and kidneys of rats treated with Na2S2O5. The presented data confirm the prooxidant activity of sulfites and suggest that increased GPx activity and plasma uric acid levels may partially reduce the observed renal and hepatocellular oxidative damage caused via the ingestion of sulfites.

Physicochemical Compatibility of Propofol-Lidocaine Mixture

To examine the physicochemical stability of combinations of propofol-lidocaine mixtures frequently used in clinical practice, we added lidocaine 5, 10, 20, or 40 mg to commercially available 1% propofol 20 mL. To assess chemical stability, propofol concentrations were determined by gas chromatography assay for 24 h after preparation of the mixture. In addition, scanning electron microscopy was used to determine the maximum detectable droplet size in randomly selected fields. Macroscopically, separate, colorless layers were first seen at 3 and 24 h after the addition of 40 and 20 mg of lidocaine to propofol, respectively, whereas the mixture with 5 or 10 mg of lidocaine was macroscopically stable. Propofol concentrations in the mixture with 40 mg of lidocaine decreased linearly and significantly from 4 to 24 h after preparation, whereas those combined with other lidocaine doses were unchanged compared with baseline concentrations. Scanning electron microscopy showed that droplets with diameters >or=5 microm first appeared 30 min after the addition of 40 mg of lidocaine to propofol, and the emulsion droplets were enlarged in a time- and dose-dependent fashion. Our results indicate that the addition of lidocaine to propofol results in a coalescence of oil droplets, which finally proceeds to a visible separate layer. Depending on the dose of lidocaine and the duration between its preparation and administration, this combination may pose the risk of pulmonary embolism.

IMPLICATIONS

The addition of lidocaine to propofol results in time- and dose-dependent increases in oil droplet diameters in emulsion. This mixture is physicochemically unstable over time and may cause pulmonary embolism, depending on the dose of lidocaine.