Injectable anaesthetics

Salfan is an injectable anaesthetic for use in cats although it has also been used in other small animals. In cats, it may produce oedema of the ears and paws following a dmini stra ti on. 445 However, the most serious effects were laryngeal and pulmonary oedema which were occasionally severe and resulted in the deaths of affected cats. " This appears to be due to the release of histamine or a histamine-like substance caused by the solubilising agent Cre-mophor EL, a polyethoxylated castor oil derivative used in the formulation. 

In humans, the product produces hyperpnoea on administration and apnoea following overdose. It also produces marked depression in cardiopulmonary function in humans and in other animals.There are no reports of adverse reactions in humans following accidental self-injection or through any other routes of exposure and Salfan has largely been replaced by other injectable anaesthetics and notably by propofol (Chapter 5). 

C. It is secreted along with noradrenaline by the adrenal medulla, from which it may be obtained. It may be synthesized from catechol. It is used as the acid tartrate in the treatment of allergic reactions and circulatory collapse. It is included in some local anaesthetic injections in order to constrict blood vessels locally and slow the disappearance of anaesthetic from the site of injection. Ultimately it induces cellular activation of phosphorylase which promotes catabolism of glycogen to glucose. 

White crystals, m.p. 90-9 rC. Prepared fromp-nitrotoluene by way of p-aminobenzoic acid. It is used as a local anaesthetic on mucous surfaces internally and by injection, and is taken internally to relieve gastric pain. 

Z. Yu and D. Westerlund, Direct injection of large volumes of plasma in a columnswitching system for the analysis of local anaesthetics , II. Determination of bupivacaine in human plasma with an alkyl-diol silica precolumn , ]. Chromatogr. A 725 149-155 (1996). 

After local anaesthetic injection, onset of nerve block and duration depends mainly on lipid solubility and on the region in where the diug is injected. In some formulations adrenaline is added to prolong the blocking action by inducing regional vasoconstriction and hereby reduce absorption and metabolisation. 

The amide local anaesthetic lidocaine may also be used as an antianhythmic for ventricular tachycardia and exra-systoles after injection into the blood circulation. Drugs with high lipid solubility such as bupivacaine cannot be used for these purposes because their prolonged binding to the channel may induce dysrhythmias or asystolic heart failure [3]. Systemically applied lidocaine has also been used successfully in some cases of neuropathic pain syndromes [4]. Here, electrical activity in the peripheral nervous system is reduced by used-dependent but incomplete sodium channel blockade. 

Breit S, Rueff F, PrzybiUa B Deep impact contact allergy after subcutaneous injection of local anesthetics. Contact Dermatitis 2001 45 296-297. Orasch CE, Helbling A, Zanni MP, Yawalkar N. Hari Y Pichler WJ T-cell reaction to local anaesthetics relationship to angioedema and urticaria after subcutaneous application-patch testing and LTT in patients with adverse reaction to local anaesthetics. Clin Exp Allergy 1999 29 1549-1554. 

A series of thiazole-based DGAT-l inhibitors typified by the highly lipophilic compound 10 was disclosed [33]. This report described a tail-vein injection assay wherein a test compound (10, 30, and lOOmg/kg) and 20% emulsion containing a fatty acid mix were orally administered to male C57BL/6N mouse at 0.3ml/mouse. After 1 h following test compound administration, mice were anaesthetized and... 

The site http //www.oyston.com/history has afascinating history of the topic, mentioning such early anaesthetics as ether, chloroform and nitrous oxide. Local anaesthetics are often injected in the form of liquids or solutions, see the article pharmacology of local anaesthetic agents by a British anaesthetist, Dr J. M. Tuckley, may be found... 

The proof that fluorocitrate is indeed the toxic substance is shown by injecting 30 mg. of enzymically produced fluorocitrate within the skull of an anaesthetized pigeon. Some 10 min. after the bird came round, convulsions and death followed. On the other hand, an intracranial injection of fluoroacetate in larger amounts produces no convulsions. This fact indicates that brain tissue does not synthesize fluorocitrate from fluoroacetate, and suggests that convulsions occurring after intraperitoneal injections by fluoroacetate are due to penetration to the brain by fluorocitrate synthesized elsewhere. 

Journal of Pharmacology and Experimental Therapeutics Figure 12. Changes in mean arterial pressure ( S.E.) after ICV injection of 500 fig of d-propranolol to conscious rabbits and rabbits anaesthetized uHth sodium... 

Naunyn-Schmiedeberg s Archives of Pharmacology Figure 10. Blood pressure and heart frequency in an anaesthetized cat with sectioned vagi and pretreatment with atropine (1 mg/kg). Decrease of blood pressure and heart rate in beats/min (S/min) after intracisternal (i.ci.) and intravenous (i.v.) injection... 

Sedated and anaesthetized rats received a lateral (mini-) thoracotomy and a pistil (3x6mm chilled to -193° G) was advanced through the hole in the chest and pressed onto the surface of the heart for 30 sec. The procedure was repeated 10 times in order to generate a cryolesion of reproducible size. GFP-transduced mesenchymal stem cells were directly injected into the borderzone of the developing ischemia (2x left lateral, 2x right lateral, lx apical). Each injection contained 8x10 mesenchymal stem cells in a volume of 30 pi (Jaquet et al., 2005). 

Bupivacaine is an anaesthetic with a slow onset but a long duration of action. It is indicated for continuous epidural analgesia in labour. Xylocoine is the proprietary preparation of lidocaine (lignocoine). Lidocoine injections ore used in dentistry. 

Quantitative measurement of diffusional uptake and carrier-mediated transport of nutrients and drugs in experimental animals was greatly facilitated with the introduction of Olden dorfs brain uptake index (BUI) [42].Test and reference tracers are injected as an intraarterial bolus into the carotid artery of the anaesthetized animal. After 5 s the animal is killed and the brain is removed for radioactivity counting. This method measures the ratio of the unidirectional brain extraction, E, of the test substance and of the reference ([ H]-water, [ " C]-butanol), which are labelled with different isotopes, during a single passage through the brain capillary bed ... 

Toxicity is found to be low and related only to the neuromuscular blocking effects. Provided that artificial ventilation is available. 10,000 times the normal effective dose evinces no acute toxicity in anaesthetized cats for up to two hours after injection.asusual. species vary in susceptibility to toxic effects. As might be expected of a higlily-charged cation, absorption from the gut is poor. No hormonal effects have been detected. 

Infiltration anaesthesia is applied fan-shaped, with as few needle punctures as possible, in close proximity of the wound or the skin area to be treated. An aspiration should always take place to avoid intravascular injection. Suitable alternatives are lidocaine (lignocaine) or prilocaine for injection 5-10 mg/ml, with or without adrenaline. When making an incision of an abscess it is sometimes difficult to use a local anaesthetic if there is a pronounced inflammatory reaction, since the effect of the anaesthetic is reduced due to an increased acidity level. While adrenaline reduces bleeding and delays dispersion of the anaesthetic, local anaesthetic/adrenaline combinations are contraindicated for local anaesthesia of digits, on the face or where the skin survival is at risk. 

Four analysts obtain the following data for a spectrophotometric analysis of an injection containing the local anaesthetic bupivacaine. The stated content of the injection is 0.25% weight in volume (w/v). 

Adrenaline is present as a vasoconstrictor in some local anaesthetic injections in a much smaller amount than the local anaesthetic itself, which obscures the absorption of adrenaline in the UV region. The selectivity of UV/visible spectroscopy for the analysis of adrenaline can be increased by complex formation, which occurs between iron (II) and molecules containing a catechol group (Fig. 4.13). These complexes are purple in colour and absorb at ca 540 nm at much longer wavelengths than for instance local anaesthetics, which do not form such complexes. The adrenaline in the injection is quantified against a standard solution of adrenaline. 

Injections of local anaesthetics often contain low concentrations of adrenaline in order to localise the anaesthetic for a time by constricting blood vessels in the vicinity of the injection. Adrenaline can be analysed by straight-phase chromatography, for instance on silica gel, but this generally requires strongly basic conditions under which the catechol group in adrenaline is unstable. Adrenaline is... 

Local anaesthetics reversibly block impulse conduction in a restricted area of the body where it is applied by topical application or local injection. They are classified as in table 2.8.1. 

Dental anaesthesia—The total amount of local anaesthetics injected is much smaller (20-80 mg of lignocaine) than that used for othr purpose. Lignocaine (2%) with adrenaline (1 80,000) is the standard local anaesthetic preparation used in dentistry which produces good soft tissue and pulpal anaesthasia and also reduce postextraction bleeding. 

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