Local anesthesia cocaine

The use of cocaine for local anesthesia has been largely replaced by synthetic drugs that produce less psychoactive effects. However, cocaine is still used sometimes for topical anesthesia of the upper respiratory tract. 

Local anesthetics are used extensively on the mucous membranes in the nose, mouth, tracheobronchial tree, and urethra. The vasoconstriction produced by some local anesthetics, cocaine especially, adds a very important advantage to their use in the nose by preventing bleeding and inducing tissue shrinkage. Topical anesthesia permits many diagnostic procedures in the awake patient, and when it is combined with infiltration techniques, excellent anesthesia may be obtained for many... 

Topical local anesthesia is often used for eye, ear, nose, and throat procedures. Satisfactory topical local anesthesia requires an agent capable of rapid penetration across the skin or mucosa, and with limited tendency to diffuse away from the site of application. Cocaine, because of its excellent penetration and local vasoconstrictor effects, has been used extensively for ear, nose and throat (ENT) procedures. Cocaine is somewhat irritating and is therefore less popular for ophthalmic procedures. Recent concern about its potential cardiotoxicity when combined with epinephrine has led most otolaryngology surgeons to switch to a combination containing lidocaine and epinephrine. Other drugs used for topical anesthesia include lidocaine-bupivacaine combinations, tetracaine, pramoxine, dibucaine, benzocaine, and dyclonine. 

The natural substance cocaine was already beeing employed for local anesthesia in ophthalmological surgery in 1884 (Vandam, 1987). However, the clinical use of cocaine is limited because of its abuse potential, its intense vasoconstriction and eventual arrhythmias due to its reuptake-inhibition of catecholamines, and instability upon sterilization. The chemical search for synthetic substitutes started in 1892 and gave rise to several compounds without abuse potential and with improved onset and duration of action, tolerability and stability of the preparation. 

The effects of temperature on local anesthesia of frog s nerve differ for various types of anesthetics cocaine, salicylamide, and monacetine are more effective on cooled nerves, whereas... 

Additions of 1/10 to 2 1/2% of urea to dilute procaine solutions increase materially their potency, to ten times, on direct application to nerve trunks, presumably by favoring penetration. The effect is not due to alkalinization. The action of local anesthetics is reported to be increased by intravenous injection of methylene blue, by the local application of caffeine or theophylline, by morphine, and by the antipyretic analgesics. Cocaine anesthesia is said to be ineffective in tissue impregnated with oxalic acid. Inflamed tissues are less susceptible to local anesthesia, probably because of their difficult penetration. 

When cocaine is applied to the conjunctiva, it produces local anesthesia (which may not extend to the iris), local anemia (which extends to the iris but not to the retina), and submaximal dilatation of the pupil by peripheral sympathetic stimulation. Mydriasis occurs also on systemic administration. The accommodation is impaired, but the light reflex is preserved there is some exophthalmos. The intraocular pressure is usually lowered, but may be increased. The mydriasis and its associated phenomena are not produced by most of the cocaine substitutes. 

Most surgeons in the UK use local anesthesia with cocaine for nasal operations because of the superior operative field it provides and because they consider it to be safe, even with adrenaline. The incidence of adverse reactions to cocaine given in this way is reportedly low, and serious complications are less common than with general anesthesia. These conclusions were based on a postal survey of all British Associations of Otolaryngologists and Head and Neck Surgeons. Only... 

Coca-Cola was originally flavored with extracts from the leaves of the coca plant and the kola nut. Coca is grown in northern South America the Indians of Peru and Bolivia have for centuries chewed the leaves to relieve the pangs of hunger and high mountain cold. The cocaine from the leaves causes local anesthesia of the stomach. It has limited use as a local anesthetic for surgery on the eye, nose, and throat. Unfortunately it is now a widely abused illicit drug. Kola nuts contciin about 3% caffeine as well as a number of other alkaloids. The kola tree is in the same family as the cacao tree from which cocoa cmd chocolate cu-e obtained. Modem cola drinks do not contain cocaine however, Coca-Cola contains 43 mg of caffeine per... 

Cocaine is used for topical local anesthesia of mucous membranes. It is also a drug of abuse. 

Cocaine hydrochloride should melt at 180°-186°(B.E), 183°(P.G.), 186° (Fr Codex). It should be perfectly colour-less, and should afford a bright, neutral solution in water. This salt of cocaine is the one most generally employed in medicine. It is largely used for producing local anesthesia in minor operations and in dental practice. Given internally, or in small hypodermic doses, it acts as a nerve stimulant, restorative, and tonic. The mental exhilaration it produces often conduces to the formation of the cocaine habit, which is even more unfortunate than the morphia habit in its results. Source Barrowcliff 1920... 

Local anesthesia began in Vienna (1884) when Carl KoUer administered cocaine, locally, over cornea, in order to anaesthetize the eye before cataract surgery. He noticed that the drug was able to prevent the oculomotor reflex in frogs. Cocaine had been previously isolated from coca leaves by Albert Nieman in 1860. Before this founding step, local sensitivity could be abolished by the dermal administration of organic derivatives like diethyl ether or ethylene chloride on the skin. Few years later, WiUiam Halsted in the United States used cocaine... 

Cocaine No Minutes to hours To cause vasoconstriction atHl local anesthesia... 

Cocaine has been shown to inhibit the reuptake of norepinephrine in the sympathomimetic nerve terminal. Local anesthesia probably results from a membrane effect. Small doses cause an increase in respiratory rate whereas large amounts lead to death from respiratory depression or cardiac arrest. 

The first clinical uses of a local anesthetic agent occurred in 1884, when cocaine was employed as a topical agent for eye surgery and to produce a nerve block. These events inaugurated a new era, that of regional anesthesia. New applications were developed, including spinal, epidural, and caudal anesthesia. The search for a better local anesthetic led to chemical synthesis of a number of other compounds that have more selective local anesthetic properties and few systemic side effects. 

Physiologically, cocaine is an anesthetic and a mydriatic (dilates the pupil of the eye). It is bitter to the taste and very poisonous. When taken internally it acts on the central nervous system causing paralysis and delusions. The importance of cocaine in medicine is as a local anesthetic, and though used originally for minor operations it is now administered for larger ones. The anesthesia produced is of short duration. 

Anesthesia of the mucous membranes of the ear. nose, and throat is usually brought about by use of aqueous solutions of the. salts of tetracaine, lignocainc. or cocaine. The vasodilator effect of cocaine reduces bleeding in surgical procedures. However, all local ane.sthetics are rapidly absorbed through mucoas membranes, and so their ase may be accompanied by an increa.scd risk of toxic. systemic reactions. As a result, dosage must be carefully controlled. 

Tropacocaine resembles cocaine in its stimulant action upon the nerve centers, and also in its local anesthetic action. It differs from cocaine, however, in that it does not cause local constriction of the blood vessels, and that it has very little influence upon the pupil. Sollmann J.A.M.A., 1918, Ixx, 216) has shown that it is approximately equal to cocaine in its anesthetic power and Eggleston and Hatcher that it is distinctly less toxic. It has been used chiefly in the so-called spinal anesthesia and a large number of surgeons have reported favorably upon it. A dose of one grain (0.06 Gm.) is ordinarily recommended, although a number of authors have used larger quantities without evil effects. 

Tropacocaine is employed as a local anesthetic and closely resembles cocaine in its action. It is said to possess only one-half the toxicity of cocaine and to produce less dilation of the pupil of the eye. Anesthesia sets in more rapidly and is more prolonged than in the case of cocaine. In lumbar anesthesia tropacocaine is indicated as the most reliable and least dangerous of the drugs in use. 

Trade name Cocaine Indications Topical anesthesia Category Anesthetic, local CNS stimulant Half-life 75 minutes... 

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