As local anesthetic

Topical anesthetics temporarily inhibit the conduction of impulses from sensory nerve fibers. These drug s may be used to relieve itching and pain due to skin conditions, such as minor bums, fungus infections, insect bites, rashes, sunburn, and plant poisoning, such as poison ivy. Some are applied to mucous membranes as local anesthetics. Examples of local anesthetics include benzocaine (Lanacane), dibucadne (Nupereainal), and lidocaine (Xylocadne). 

Mannich, C. Krosche, W. Arch. Pharm. 1912, 250, 647. Carl U. F. Mannich (1877-1947) was bom in Breslau, Germany. After receiving a Ph.D. at Basel in 1903, he served on the faculties of Gottingen, Frankfurt and Berlin. Mannich synthesized many esters of p-aminobenzoic acid as local anesthetics. 

Several first-generation Hi antagonists are potent local anesthetics. They block sodium channels in excitable membranes in the same fashion as procaine and lidocaine. Diphenhydramine and promethazine are actually more potent than procaine as local anesthetics. They are occasionally used to produce local anesthesia in patients allergic to conventional local anesthetic drugs. A small number of these agents also block potassium channels this action is discussed below (see Toxicity). 

Class I antiarrhythmic drugs are essentially sodium channel blockers.5,27,29 These drugs bind to membrane sodium channels in various excitable tissues, including myocardial cells. In cardiac tissues, class I drugs normalize the rate of sodium entry into cardiac tissues and thereby help control cardiac excitation and conduction.8,27 Certain class I agents (e.g., lidocaine) are also used as local anesthetics the way that these drugs bind to sodium channels is discussed in more detail in Chapter 12. 

The compounds from the prior art reference cited against the Albrecht application possessed utility in that they were active as local anesthetics, but they lacked overall utility in that their irritant qualities would exceed their usefulness as local anesthetics. It appeared to the CCPA that a chemist of skill in the art, reading the cited reference for all that it disclosed, would not have been motivated to make additional close analogues based on the likelihood that they too would be irritants and thus have no practical utility.30... 

Since channel residence in the different conformational states is controlled by membrane voltage, state-dependent sodium channel blockers show voltage- and use-dependence, i.e., their potency increases with more depolarized holding potentials and with repetitive stimulation [8-10]. State-dependent sodium channel blockers are used clinically as local anesthetics and to treat epileptic seizures and certain arrhythmias. 

Cocaine is a powerful CNS stimulant as well as local anesthetic (13). It is isolated from the leaves of Erythrolon coca, a tree indigenous to Peru and Bolivia. Cocaine effectively blocks the uptake of catecholamines into presynaptic neurons and thus promotes the activity of synapses (both central and peripheral) involving these amines (22). 

Ethyl chloride, Chlor-ethane, CH3—CH2CI, and ethyl bromide, brom ethane, CH3—CH2Br, are both used as local anesthetics, the latter in dentistry. The former is a gas, boiling as 12.2°, which can be readily condensed to a liquid and is used technically in this form. Ethyl bromide is a chloroform-like liquid boiling at 38.4°. 

Arrhythmias are caused by abnormal pacemaker activity or abnormal impulse propagation. Antiarrhythmic drugs are often classified according to the Vaughan-William scheme, which organizes agents based on channel or receptor involved (Table 2-1). Class I agents block sodium channels and are sometimes referred to as "local anesthetics." The... 

Etaminalion of the active compounds discussed in the following sections reveals that at least one cyclic substituent iplienyl. thienyl, or other) is a common feature in almost all anticholinergic molecules. Aromatic substitution is often g l in connection with the acidic moiety of the ester func- >on. Virtually all acids used, however, are of the aryl-substi-tnied acetic acid variety. Use of aromatic acids leads to low mivity of these compounds as anticholinergics but potential itivity as local anesthetics. 

Plectranthus marrubioides Kenya imports all the camphor used in the local industry. The camphor content in the essential oil of P. marrubioides would be a good source for use in the pharmacentical industry, especially for preparatiorrs such as local anesthetics, remedies for rheirmatic and mnscular pairts and for respiratory conditions. These potential nses justify cultivation of this plant on a commercial scale. The plant is easily propagated from cnttings. It can withstand adverse weather conditions and can also co-exist with other plants as an rmdergrowth in forests (66). 

Many more aminobenzoate amino esters were synthesized, and some were developed as local anesthetics. The only ones still of importance are tetracaine, No. 3, and chloropro-caine, No. 1. An examination of the data on the three aminoalkyl p-aminobenzoates (Nos. 1, 2, and 3, Table 13-6) illustrates some classic. SARs within that series. For example, the o-chloro atom of chloroprocaine would predictably enhance the ester groups instability as exemplified by a four-fold faster rate of hydrolysis—and therefore inactivation (15-fold when compared with tetracaine). The partition coefficients indicate a 570 times greater... 

Many of the medicinal amines are analgesics (pain relievers) or anesthetics (pain blockers). Novocaine and related compounds, for example, are used as local anesthetics. Demerol is a very strong pain reliever. 

Hydrochloride, C,4HjjCIN202, dimorphic crystals. Rectangular plates, mp 153,5° rods, mp 176°, Bitter taste followed by a sense of numbness. Sol in water sparingly sol in alcohol insol in ether, chloroform, benzene. therap cat Hydrochloride as local anesthetic-therap CAT (Vet) Topical anesthetic (ocular). 

Hydrochloride, C.jH jNOj.HCI, crystals mp 172.5-173.5°. therap cat Hydrochloride as local anesthetic. 

These drugs block sodium channels. They essentially act as local anesthetics, reducing the conduction rate and amplitude of electrical impulses. 

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