[Anaesthetics and breast feeding]

Many women undergo anaesthetic procedures related to childbirth or during the period of lactation. Most anaesthetic drugs are lipophilic and are thus excreted into breast milk. This article summarises available knowledge regarding anaesthetics, their excretion into breast milk and possible effects on the suckling infant. The consequences of such an exposure are discussed in terms of whether breast-feeding should be allowed or not after anaesthetic procedures.

Anesthetic properties of the ketone bodies beta-hydroxybutyric acid and acetone

BACKGROUND

We tested the hypothesis that two metabolites that are elevated in ketosis (beta-hydroxybutyric acid, and acetone) modulate ion channels in a manner similar to anesthetics and produce anesthesia in animals.

METHODS

alpha1beta2gamma2sgamma-aminobutyric acid type A (GABA(A)), alpha1 glycine, NR1/NR2A N-methyl-d-aspartate, and two pore domain TRESK channels were expressed in Xenopus laevis oocytes and studied using two-electrode voltage clamping. The effect of beta hydroxybutyric acid and acetone on channel function was measured. The anesthetic effects of these drugs were measured in X. laevis tadpoles.

RESULTS

Both beta hydroxybutyric acid and acetone enhanced glycine receptor function in the concentration range that is obtained in ketoacidosis in humans. Beta hydroxybutyric acid also enhanced GABA(A) receptor function at these concentrations. Both acetone and beta-hydroxybutyric acid anesthetized tadpoles, with an EC50 for acetone of 264 +/- 2 mM (mean +/- se) and for beta-hydroxybutyric acid of 151 +/- 11 mM at pH 7.0. Acetone enhanced GABA(A) receptors at concentrations of 50 mM and above. Inhibition of TRESK channel function was seen with 100 mM acetone or larger concentration. N-methyl-D-aspartate receptor function was inhibited at concentrations of acetone of 200 mM and larger.

CONCLUSIONS

Beta hydroxybutyric acid and acetone are anesthetics. Both ketone bodies enhance inhibitory glycine receptors at concentrations observed clinically in ketoacidosis. In addition, beta-hydroxybutyric acid enhances GABA(A) receptor function at these concentrations. Subanesthetic concentrations of these drugs may contribute to the lethargy and impairment of consciousness seen in ketoacidosis.

Effects of hypothermia on drug disposition, metabolism, and response: A focus of hypothermia-mediated alterations on the cytochrome P450 enzyme system

OBJECTIVES

Therapeutic hypothermia has been shown to decrease neurologic damage in patients experiencing out-of-hospital cardiac arrest. In addition to being treated with hypothermia, critically ill patients are treated with an extensive pharmacotherapeutic regimen. The effects of hypothermia on drug disposition increase the probability for unanticipated toxicity, which could limit its putative benefit. This review examines the effects of therapeutic hypothermia on the disposition, metabolism, and response of drugs commonly used in the intensive care unit, with a focus on the cytochrome P450 enzyme system.

DATA SOURCES AND STUDY SELECTION

A MEDLINE/PubMed search from 1965 to June 2006 was conducted using the search terms hypothermia, drug metabolism, P450, critical care, cardiac arrest, traumatic brain injury, and pharmacokinetics.

DATA EXTRACTION AND SYNTHESIS

Twenty-one studies were included in this review. The effects of therapeutic hypothermia on drug disposition include both the effects during cooling and the effects after rewarming on drug metabolism and response. The studies cited in this review demonstrate that the addition of mild to moderate hypothermia decreases the systemic clearance of cytochrome P450 metabolized drugs between approximately 7% and 22% per degree Celsius below 37degreesC during cooling. The addition of hypothermia decreases the potency and efficacy of certain drugs.

CONCLUSIONS

This review provides evidence that the therapeutic index of drugs is narrowed during hypothermia. The magnitude of these alterations indicates that intensivists must be aware of these alterations in order to maximize the therapeutic efficacy of this modality. In addition to increased clinical attention, future research efforts are essential to delineate precise dosing guidelines and mechanisms of the effect of hypothermia on drug disposition and response.

[Effects of brain stem and spinal cord by isoflurane inhibiting nociceptive reflex]

OBJECTIVE

To explore the effect positions of the volatile anesthetic inhibiting the nociceptive reflex in the central nervous system.

METHODS

Thirty adult SD rats were randomly and equally divided into two groups that the lip and hind paw of rats were held by clamp. The minimum alveolar concentration (MAC) was determined by clamping two places: one was to clamp the hind paw of rats, of which the nervous reflex is controlled via the spinal cord; the another group was to clamp the lip of rats, of which the nervous reflex is controlled through the brain stem.

RESULTS

The isoflurane MAC was 1.44% +/- 0.09% in clamping the hind paw group, while 1.29% +/- 0.11% for clamping the lip group (P < 0.05).

CONCLUSION

Both brain stem and spinal cord are the effect positions of volatile anesthetics (especially isoflurane).

The Common Chemical Motifs Within Anesthetic Binding Sites

BACKGROUND

It is not yet possible to obtain crystal structures of anesthetic molecules bound to proteins that are plausible neuronal targets; for example, ligand-gated ion channels. However, there are x-ray crystal structures in which anesthetics are complexed with proteins that are not directly related to anesthetic action. Much useful information about anesthetic-protein interactions can be derived from the x-ray crystal structures of halothane-cholesterol oxidase, bromoform-luciferase, halothane-albumin, and dichloroethane-dehalogenase. These structures show anesthetic-protein interactions at the atomic level.

METHODS

We obtained the known coordinate files for bromoform-luciferase, halothane- albumin, dichloroethane-dehalogenase, and halothane-cholesterol oxidase. These were then modified by adding hydrogens, edited into subsets, and underwent a series of restrained molecular mechanics optimizations. Final analysis of anesthetic polarization within the anesthetic binding site occurred via combined molecular mechanics-quantum mechanics calculations.

RESULTS

The anesthetic binding sites within these well-characterized anesthetic-protein complexes possess a set of common characteristics that we refer to as "binding motifs." The common features of these motifs are polar and nonpolar interactions within an amphiphilic binding cavity, including the presence of weak hydrogen bond interactions with amino acids and water molecules. Calculations also demonstrated the polarizing effect of the amphipathic binding sites on what are otherwise considered quite hydrophobic anesthetics. This polarization appears energetically favorable.

CONCLUSIONS

Anesthetic binding to proteins involves amphipathic interactions.

Photoactive analogues of the haloether anesthetics provide high-resolution features from low-affinity interactions

The difficulty in obtaining binding target and site information for low-affinity drugs, like the inhaled anesthetics, has limited identification of their molecular effectors. Because such information can be provided by photoactive analogues, we designed, synthesized, and characterized a novel diazirnyl haloether that closely mimics isoflurane, the most widely used clinical general anesthetic. This compound, H-diaziflurane, is a nontoxic, potent anesthetic that potentiates GABA-gated ion channels in primary cultures of hippocampal neurons. Calorimetric and structural characterizations show that H-diaziflurane binds a model anesthetic host protein with similar energetics as isoflurane and forms photoadducts with residues lining the isoflurane binding site. H-diaziflurane will be immediately useful for identifying targets and sites important for the molecular pharmacology of the inhaled haloether anesthetics.

Recent neurochemical basis of inert gas narcosis and pressure effects

Compressed air or a nitrogen-oxygen mixture produces from 0.3 MPa nitrogen narcosis. The traditional view was that anaesthesia or narcosis occurs when the volume of a hydrophobic site is caused to expand beyond a critical amount by the absorption of molecules of a narcotic gas. The observation of the pressure reversal effect on general anaesthesia has for a long time supported the lipid theory. However, recently, protein theories are in increasing consideration since results have been interpreted as evidence for a direct anaesthetic-protein interaction. The question is to know whether inert gases act by binding processes on proteins of neurotransmitter receptors. Compression with breathing mixtures where nitrogen is replaced by helium which has a low narcotic potency induces from 1 MPa, the high pressure nervous syndrome which is related to neurochemical disturbances including changes of the amino-acid and monoamine neurotransmissions. The use of narcotic gas (nitrogen or hydrogen) added to a helium-oxygen mixture, reduced some symptoms of the HPNS but also had some effects due to an additional effect of the narcotic potency of the gas. The researches performed at the level of basal ganglia of the rat brain and particularly the nigro-striatal pathway involved in the control of the motor, locomotor and cognitive functions, disrupted by narcosis or pressure, have indicated that GABAergic neurotransmission is implicated via GABAa receptors.

Concentrations of extracellular free zinc (pZn)e in the central nervous system during simple anesthetization, ischemia and reperfusion

"Free Zn2+" (rapidly exchangeable Zn2+) is stored along with glutamate in the presynaptic terminals of specific specialized (gluzinergic) cerebrocortical neurons. This synaptically releasable Zn2+ has been recognized as a potent modulator of glutamatergic transmission and as a key toxin in excitotoxic neuronal injury. Surprisingly (despite abundant work on bound zinc), neither the baseline concentration of free Zn2+ in the brain nor the presumed co-release of free Zn2+ and glutamate has ever been directly observed in the intact brain in vivo. Here, we show for the first time in dialysates of rat and rabbit brain and human CSF samples from lumbar punctures that: (i) the resting or "tonic" level of free Zn2+ signal in the extracellular fluid of the rat, rabbit and human being is approximately 19 nM (95% range: 5-25 nM). This concentration is 15,000-fold lower than the "300 microM" concentration which is often used as the "physiological" concentration of free zinc for stimulating neural tissue. (ii) During ischemia and reperfusion in the rabbit, free zinc and glutamate are (as has often been presumed) released together into the extracellular fluid. (iii) Unexpectedly, Zn2+ is also released alone (without glutamate) at a variable concentration for several hours during the reperfusion aftermath following ischemia. The source(s) of this latter prolonged release of Zn2+ is/are presumed to be non-synaptic and is/are now under investigation. We conclude that both Zn2+ and glutamate signaling occur in excitotoxicity, perhaps by two (or more) different release mechanisms.

Monolayers of a model anesthetic-binding membrane protein: formation, characterization, and halothane-binding affinity

hbAP0 is a model membrane protein designed to possess an anesthetic-binding cavity in its hydrophilic domain and a cation channel in its hydrophobic domain. Grazing incidence x-ray diffraction shows that hbAP0 forms four-helix bundles that are vectorially oriented within Langmuir monolayers at the air-water interface. Single monolayers of hbAP0 on alkylated solid substrates would provide an optimal system for detailed structural and dynamical studies of anesthetic-peptide interaction via x-ray and neutron scattering and polarized spectroscopic techniques. Langmuir-Blodgett and Langmuir-Schaeffer deposition and self-assembly techniques were used to form single monolayer films of the vectorially oriented peptide hbAP0 via both chemisorption and physisorption onto suitably alkylated solid substrates. The films were characterized by ultraviolet absorption, ellipsometry, circular dichroism, and polarized Fourier transform infrared spectroscopy. The alpha-helical secondary structure of the peptide was retained in the films. Under certain conditions, the average orientation of the helical axis was inclined relative to the plane of the substrate, approaching perpendicular in some cases. The halothane-binding affinity of the vectorially oriented hbAP0 peptide in the single monolayers, with the volatile anesthetic introduced into the moist vapor environment of the monolayer, was found to be similar to that for the detergent-solubilized peptide.

SELECTIVE PATHWAYS FOR THE METABOLISM OF PHENCYCLIDINE BY CYTOCHROME P450 2B ENZYMES: IDENTIFICATION OF ELECTROPHILIC METABOLITES, GLUTATHIONE, AND N-ACETYL CYSTEINE ADDUCTS

The metabolism of phencyclidine (PCP) has been studied previously in cytochrome P450 (P450)-containing microsomal systems. However, the reactive intermediate(s) that covalently binds to the P450 and leads to inactivation or leaves the active site to modify other proteins has not been identified. In this study two electrophilic intermediates of PCP were identified by mass spectrometry and by trapping with reduced glutathione (GSH) or N-acetyl cysteine (NAC). The tentative structures of these electrophilic intermediates were determined using mass spectrometry. P450s 2B1 and 2B4 formed a metabolite that exhibited an m/z of 240 corresponding to the mass of the 2,3-dihydropyridinium species of PCP or its conjugate base, the 1,2-dihydropyridine. Chemical reduction of the incubation mixture using NaBH4 resulted in the disappearance of the signal at m/z 240, consistent with reduction of a 2,3-dihydropyridinium species. Furthermore, the reactive metabolite trapped by GSH resulted in an adduct exhibiting an m/z of 547, consistent with the mass of the 2,3-dihydropyridinium species of PCP (m/z 240), that has reacted with a molecule of GSH (m/z 308). However, P450 2B6 formed a different reactive intermediate of PCP that was isolated as a GSH adduct exhibiting an m/z of 581 and an NAC adduct with an m/z of 437. Liquid chromatography-tandem mass spectrometry analysis of these adducts suggested that a di-oxygenated iminium metabolite of PCP could be the reactive intermediate formed by P450 2B6 but not by the other 2B isoforms. These data suggest that P450 2B6 favors oxidation pathways for PCP metabolism that are different from those of P450s 2B1 and 2B4.

Emerging molecular mechanisms of general anesthetic action

General anesthetics are essential to modern medicine, and yet a detailed understanding of their mechanisms of action is lacking. General anesthetics were once believed to be "drugs without receptors" but this view has been largely abandoned. During the past decade significant progress in our understanding of the mechanisms of general anesthetic action at the molecular, cellular and neural systems levels has been made. Different molecular targets in various regions of the nervous system are involved in the multiple components of anesthetic action, and these targets can vary between specific anesthetics. Neurotransmitter-gated ion channels, particularly receptors for GABA and glutamate, are modulated by most anesthetics, at both synaptic and extrasynaptic sites, and additional ion channels and receptors are also being recognized as important targets for general anesthetics. In this article, these developments, which have important implications for the development of more-selective anesthetics, are reviewed in the context of recent advances in ion channel structure and function.

Flotillins and the PHB Domain Protein Family: Rafts, Worms and Anaesthetics

While our understanding of lipid microdomains has advanced in recent years, many aspects of their formation and dynamics are still unclear. In particular, the molecular determinants that facilitate the partitioning of integral membrane proteins into lipid raft domains are yet to be clarified. This review focuses on a family of raft-associated integral membrane proteins, termed flotillins, which belongs to a larger class of integral membrane proteins that carry an evolutionarily conserved domain called the prohibitin homology (PHB) domain. A number of studies now suggest that eucaryotic proteins carrying this domain have affinity for lipid raft domains. The PHB domain is carried by a diverse array of proteins including stomatin, podocin, the archetypal PHB protein, prohibitin, lower eucaryotic proteins such as the Dictyostelium discoideum proteins vacuolin A and vacuolin B and the Caenorhabditis elegans proteins unc-1, unc-24 and mec-2. The presence of this domain in some procaryotic proteins suggests that the PHB domain may constitute a primordial lipid recognition motif. Recent work has provided new insights into the trafficking and targeting of flotillin and other PHB domain proteins. While the function of this large family of proteins remains unclear, studies of the C. elegans PHB proteins suggest possible links to a class of volatile anaesthetics raising the possibility that these lipophilic agents could influence lipid raft domains. This review will discuss recent insights into the cell biology of flotillins and the large family of evolutionarily conserved PHB domain proteins.

Formation and toxicity of anesthetic degradation products

Toxic degradation products are formed from a range of old and modern anesthetic agents. The common element in the formation of degradation products is the reaction of the anesthetic agent with the bases in the carbon dioxide absorbents in the anesthesia circuit. This reaction results in the conversion of trichloroethylene to dichloroacetylene, halothane to 2-bromo-2-chloro-1,1-difluoroethylene, sevoflurane to 2-(fluoromethoxy)-1,1,3,3,3-pentafluoro-1-propene (Compound A), and desflurane, isoflurane, and enflurane to carbon monoxide. Dichloroacetylene, 2-bromo-2-chloro-1,1-difluoroethylene, and Compound A form glutathione S-conjugates that undergo hydrolysis to cysteine S-conjugates and bioactivation of the cysteine S-conjugates by renal cysteine conjugate beta-lyase to give nephrotoxic metabolites. The elucidation of the mechanisms of formation and bioactivation of degradation products has allowed for the safe use of anesthetics that may undergo degradation in the anesthesia circuit.

The lipid/protein interface as xenobiotic target site

High-resolution X-ray diffraction structures of integral membrane proteins have revealed various binding modes of lipids, but current spectroscopic studies still use uniform macroscopic binding constants to describe lipid binding. The Adair approach employing microscopic lipid-binding constants has previously been taken to explain the enhancement of agonist binding to the nicotinic acetylcholine receptor by general anaesthetics in terms of the competitive displacement of essential lipid activator molecules [Walcher S, Altschuh J & Sandermann H (2001) J. Biol. Chem.276, 42191-42195]. This approach was extended to tadpole narcosis induced by alcohols. A single class, or two different classes of lipid activator binding sites, are considered. Microscopic lipid and inhibitor binding constants are derived and allow a close fit to dose-response curves of tadpole narcosis on the basis of a preferential displacement of more loosely bound essential lipid activator molecules. This study illustrates the potential of the Adair approach to resolve protein-bound lipid populations.

Pharmacogenetics of Anesthetic and Analgesic Agents

Predicting a patient's response to a particular drug has long been a goal of clinicians. Rapid advances in molecular biology have enabled researchers to identify associations between an individual's genetic profile and drug response. Pharmacogenetics is the study of the molecular mechanisms that underlie individual differences in drug metabolism, efficacy, and side effects. The pharmacogenetics of commonly used anesthetic and analgesic agents are reviewed.

Homology Modeling of a Human Glycine Alpha 1 Receptor Reveals a Plausible Anesthetic Binding Site

The superfamily of ligand-gated ion channels (LGICs) has been implicated in anesthetic and alcohol responses. Mutations within glycine and GABA receptors have demonstrated that possible sites of anesthetic action exist within the transmembrane subunits of these receptors. The exact molecular arrangement of this transmembrane region remains at intermediate resolution with current experimental techniques. Homology modeling methods were therefore combined with experimental data to produce a more exact model of this region. A consensus from multiple bioinformatics techniques predicted the topology within the transmembrane domain of a glycine alpha one receptor (GlyRa1) to be alpha helical. This fold information was combined with sequence information using the SeqFold algorithm to search for modeling templates. Independently, the FoldMiner algorithm was used to search for templates that had structural folds similar to published coordinates of the homologous nAChR (1OED). Both SeqFold and Foldminer identified the same modeling template. The GlyRa1 sequence was aligned with this template using multiple scoring criteria. Refinement of the alignment closed gaps to produce agreement with labeling studies carried out on the homologous receptors of the superfamily. Structural assignment and refinement was achieved using Modeler. The final structure demonstrated a cavity within the core of a four-helix bundle. Residues known to be involved in modulating anesthetic potency converge on and line this cavity. This suggests that the binding sites for volatile anesthetics in the LGICs are the cavities formed within the core of transmembrane four-helix bundles.

Cytochrome P450 in neurological disease

Advances in a multitude of disciplines support an emerging role for cytochrome P450 enzymes and their metabolic substrates and end-products in the pathogenesis and treatment of central nervous system disorders, including acute cerebrovascular injury, such as stroke, chronic neurodegenerative disease, such as Alzheimer's and Parkinson's disease, as well as epilepsy, multiple sclerosis and psychiatric disorders, including anxiety and depression. The neural tissue contains its own unique set of P450 genes that are regulated in a manner that is distinct from their molecular regulation in peripheral tissue. Furthermore, brain P450s catalyze the formation of important brain signaling molecules, such as neurosteroids and eicosanoids, and metabolize substrates as diverse as vitamins A and D, cholesterol, bile acids, as well as centrally acting drugs, anesthetics and environmental neurotoxins. These unique characteristics allow this family of proteins and their metabolites to perform such vital functions in brain as neurotrophic support, neuroprotection, control of cerebral blood flow, temperature control, neuropeptide release, maintenance of brain cholesterol homoeostasis, elimination of retinoids from CNS, regulation of neurotransmitter levels and other functions important in brain physiology, development and disease.

Acute neurosteroid modulation and subunit isolation of the gamma-aminobutyric acidA receptor in the bullfrog, Rana catesbeiana

The inhibitory neurotransmitter gamma-aminobutyric acid (GABA) has multiple receptors. In mammals, the GABA(A) receptor subtype is modulated by neurosteroids. However, whether steroid interaction with the GABA(A) receptor is unique to mammals or a conserved feature in vertebrates is unknown. Thus, neurosteroid modulation of the GABA(A) receptor was investigated in the brain of the bullfrog (Rana catesbeiana) using the mammalian GABA(A) receptor agonist [(3)H]muscimol. Two neurosteroids, allopregnanolone and pregnenolone sulfate, affected [(3)H]muscimol specific binding in bullfrog brain membrane preparations. Allopregnanolone significantly increased [(3)H]muscimol specific binding in a dose- and time-dependent manner. The pattern of allopregnanolone modulation supports the hypothesis that the bullfrog brain possesses both high-affinity and low-affinity [(3)H]muscimol binding sites. Unlike allopregnanolone, pregnenolone sulfate showed biphasic modulation with increased [(3)H]muscimol specific binding at low nanomolar concentrations and decreased specific binding at micromolar concentrations. Additionally, three cDNA fragments with significant homology to mammalian GABA(A) receptor subunits were isolated from the bullfrog brain. These fragments belong to the alpha1, beta1, and gamma2 subunit families. In mammals, GABA(A) receptors composed of these specific subunit isoforms are effectively modulated by neurosteroids, including allopregnanolone. Neurosteroid modulation of the amphibian brain GABA(A) receptor is therefore supported by both [(3)H]muscimol binding studies and subunit sequences. Allopregnanolone and pregnenolone sulfate modulation of this receptor may thus represent a significant mechanism for steroid influence on amphibian brain and behavior.

Evaluation of the induction and recovery characteristics of anesthesia with desflurane in cats

OBJECTIVE

To qualitatively and quantitatively evaluate the characteristics of desflurane with regard to the induction of and recovery from anesthesia in cats.

ANIMALS

6 cats.

PROCEDURE

Anesthesia was induced and maintained with desflurane in oxygen. Individual minimum alveolar concentration (MAC) values were determined; anesthesia was maintained at 1.25 x MAC for a total anesthesia time (including MAC determination) of 5 hours. Cats were allowed to recover from anesthesia. Induction and recovery periods were video recorded and later scored by use of a grading scale from 0 to 100 (100 being the best outcome). Timing of events was recorded.

RESULTS

The MAC of desflurane was 10.27 +/- 1.06%, and mean dose was 5.6 +/- 0.2 MAC-hours. Times to loss of coordination, recumbency, and endotracheal intubation were 1.3 +/- 0.4, 2.3 +/- 0.3, and 6.4 +/- 1.1 minutes, respectively. Median score for quality of anesthetic induction was 93 (range, 91 to 94). Times to first movement, extubation, standing, and ability to jump and land with coordination were 2.8 +/- 1.0, 3.8 +/- 0.5, 14.3 +/- 3.9, and 26.4 +/- 5.1 minutes, respectively. Alveolar washout of desflurane was rapid. Median score for quality of anesthetic recovery was 94 (range, 86 to 96).

CONCLUSIONS AND CLINICAL RELEVANCE

Desflurane was associated with rapid induction of and recovery from anesthesia in cats; assessors rated the overall quality of induction and recovery as excellent. Results appear to support the use of desflurane for induction and maintenance of anesthesia in healthy cats.

Receptor desensitization by neurotransmitters in membranes: are neurotransmitters the endogenous anesthetics?

A mechanism of anesthesia is proposed that addresses one of the most troubling peculiarities of general anesthesia: the remarkably small variability of sensitivity within the human population and across a broad range of animal phyla. It is hypothesized that in addition to the rapid, saturable binding of a neurotransmitter to its receptor that results in activation, the neurotransmitter also acts indirectly on the receptor by diffusing into the postsynaptic membrane and changing its physical properties, causing a shift in receptor conformational equilibrium (desensitization). Unlike binding, this slower indirect mechanism is nonspecific: each neurotransmitter will, in principle, affect all receptors in the membrane. For proteins modeled as having only resting and active conformational states, time-dependent ion currents are predicted that exhibit many characteristics of desensitization for both inhibitory and excitatory channels. If receptors have been engineered to regulate the time course of ion currents by this mechanism, then (a) mutations that significantly alter receptor sensitivity to this effect would be lethal and (b) by design, excitatory receptors would be inhibited, but inhibitory receptors activated, so that their effects are not counterproductive. The wide range of exogenous molecules that affect the physical properties of membranes as do neurotransmitters, but that do not bind to receptors, would thus inhibit excitatory channels and activate inhibitory channels, i.e., they would act as anesthesics. The endogenous anesthetics would thus be the neurotransmitters, the survival advantage conferred by their proper membrane-mediated desensitization of receptors explaining the selection pressure for anesthesic sensitivity.

[Surgery patients' intake of herbal preparations and dietary supplements]

INTRODUCTION

Herbal medicine is being frequently used by patients around the world. Several products may interact with ordinary medicine, so it is important for doctors to know what kind of herbal medicines their patients take.

MATERIAL AND METHODS

A questionnaire was given to presurgery patients during a two-month period.

RESULTS

A total of 115 consecutive patients responded, 69 women (60%) and 46 men (40%). 50.4% had taken or still took herbal medicine, with the following distribution of gender: women 69.8%, men 30.2%. The age group was 18-82 years. The frequently used herbal medicines were fish oil, ginkgo, Echinacea, Co-Q10, garlic, and hip. Twenty-five patients took nutritional supplements with the following spread of gender: 84% women and 16% men. The frequently used nutritional supplements were Gerimax, LongoVital, and Melbrosia. Not all patients would inform their doctor about their use of herbal medicine. 28.6% retained information because of the doctor and 64.3%, did not perceive herbal medicine as "real medicine".

DISCUSSION

It is important for anaesthesiologists to know what specific kind of herbal medicines patients are using before they anaesthetize them as interactions between herbal medicine and anaesthesia are prevalent. Anaesthesiologists have to ask specific questions to receive full information regarding herbal medicines during the preoperative period.