Phenol anesthetic effect

Phenol is toxic to bacteria and fungi, and it is used as a slimicide and disinfectant. Because of its anesthetic effects, phenol is used in medicines such as ointments, ear and nose drops, cold sore lotions, throat lozenges and sprays (such as those sold under die Cepastat and Chloraseptic labels), and antiseptic lotions (EPA, 2002). 

Phenol is the common topical anesthetic for myringotomies. It is applied over the specific area of the tympanic membrane where the myringotomy is to be performed. It acts by causing instant epidermal destruction. The section of the tympanic membrane in contact with the phenol turns white owing to the anticipated proteins, indicating an anesthetic effect. Healing occurs by hyperplasia of the epithelium and connective tissue but may take some time after applications. ... 

Phenol is toxic on contact with the skin or if swallowed or inhaled. Phenol is strongly corrosive, producing possibly irreversible damage to the cornea and severe skin burns, although the skin burns are painless owing to the anesthetic effects of phenol. 

Immediately after application of phenol to the upper lip, the anesthetic effect is enough to be able to pinch the skin and draw blood without any feeling of pain (note the red spots in the photograph, taken during a chemical cheiloplasty). 

Phenol can have beneficial effects when used for medical reasons. It is an antiseptic (kills germs) when applied to the skin in small amounts and may have antiseptic properties when gargled as a mouthwash. It is an anesthetic (relieves pain) and is a component of certain sore-throat lozenges and throat sprays or gargles. Small amounts of phenol in water have been injected into nerve tissue to lessen pain associated with certain nerve disorders. Phenol destroys the outer layers of skin if allowed to remain in contact with skin, and small amounts of... 

Schmidt SH, Anniko M, Hellstrom S. 1990. Electrophysiological effects of the clinically used local anesthetics lidocaine, lidocaine-prilocaine and phenol on the rat s inner ear. Eur Arch Otorhinolaryngol 248 87-94. 

Long introduces ether as an anesthetic Locock accidentally discovers bromides as anticonvulsants Lister pioneers use of phenol as a surgical antiseptic Liebreich discovers hypnotic effects of chloral hydrate Strieker uncovers analgesic properties of salicylic acid Guthzeit and Conrad synthesize a series of barbiturates Erlich pioneers concepts of receptor and chemotherapy ... 

On the other hand, in Japan, Sang-Bai-Pi (the root bark of Chinese mulberry tree) imported from China has been used as an herbal medicine, hence a study of the components of this crude drug purchased in the Japanese market was undertaken. Its phenolic components are different from those of Japanese mulberry tree. For example, morusin (3) and kuwanon G (1) are the main phenolic components of Japanese mulberry tree, in the case of Sang-Bai-Pi , these components are minor ones, while sanggenons A (4) [16], C (5) [17], and D (33) [61] are the main components [24]. Sanggenons C (5) and D (33) showed the hypotensive effects as follows Sanggenon C (5) caused transient decrease in arterial blood pressure at the doses of 1 mg/kg in pentobarbital-anesthetized rabbit by 15 mm Hg, while at the doses of 5 mg/kg the compound (5) caused a transient decrease by 100 mm Hg, which continued for more... 

Phenol is a benzyl alcohol and a major oxidized metabolite of benzene that was introduced into medicine as an antiseptic (1). Although it can be prepared in an aqueous solution or in glycerine, it appears to be more effective when mixed in aqueous compounds. At a concentration of 0.2% it is bacteriostatic and at over 1% bactericidal (2). In addition to its uses as an antiseptic and disinfectant, phenol is also used as a sclerosant, as a local anesthetic on the skin, and as an analgesic, by injection into nerves or spinally, but its use was limited by severe adverse effects. Current medical uses include cosmetic face peeling, nerve injections, and topical anesthesia. It is also an ingredient of various topical formulations, and is used as an environmental disinfectant. 

Benzodiazepines are neurostabilizers that can counteract the initial toxic neurological effects of local anesthetics or phenol. 

With EMLA, liposoluble anesthetic molecules penetrate the stratum comeum and the rest of the epidermal barrier and soon reach the skin nerve endings. The phenol, which is also liposoluble, can get through the epidermis more quickly. On the surface the shorter contact time between the epidermis and the phenol could reduce epidermal liquefaction. Deep down, a higher concentration of phenol in the reticular dermis could cause the formation of retractile scar tissue. The concentration gradient created in the perivascular spaces of the dermis speeds up the absorption of phenol. The risk of systemic toxicity can also increase. EMLA causes vasoconstriction followed by vasodilation. Vasodilation can sometimes be seen after only 30 minutes of EMLA under occlusion. How will these vasomotor changes affect the effectiveness or absorption of phenol - and therefore its toxicity ... 

Various phenol peel formulas can be found on the market that boast of the possibilities of doing a full-face peel without anesthetic . In some cases, this means without general anesthetic and in others the patient is put on strong analgesics, sedation and premedication. Some low-dose phenol peels (around 30%) are no more painful than a trichloroacetic acid to the papillary dermis, but they are not much more effective either. 

Recently, some phenol formulas have been presented as allowing a full-face peel without any anesthetic. A phenol peel that can be applied to the whole face without any type of anesthetic is a more superficial phenol peel that does not induce regeneration of the reticular dermis of the same quality as the classic phenol peels. Less pain goes hand in hand with inadequate results the results of this type of phenol peel are the same as for a TCA peel to the papillary dermis and may not have much effect on wrinkles. The pain caused by these peels is also the same as for a TCA peel to the papillary dermis. It is pointless to put a patient through the risks of phenol toxicity only to get the results that a simple, non-toxic molecule (TCA) can achieve. An effective, full-face phenol peel should therefore be used with an anesthetic (see Chapter 33). 

Among the other notations is that acetaldehyde is to be avoided, it being a respiration inhibitor. It is related to ethyl alcohol or ethanol and also to acetic acid, but not necessarily to citric acid as involved in the carboxylic acid or citric acid cycle. Alkaloids are expectedly respiration inhibitors, and anesthetics can have respiration inhibition as a side effect. Aromatic adds such as phenol are bad news, as are arsenate, cyanide, isothiocyanate, and thiocyanate. The heavy metals cadmium, cobalt, copper, ruthenium, vanadate, and zinc are regarded as health risks, if not for respiration, for other reasons. 

Phenol is the simplest compound with an OH group attached to an aromatic ring. One of the most striking effects of the aromatic group is the greatly increased acidity of the OH group. Phenol is about 1 million times more acidic in water than a nonaromatic alcohol. Even so, it is not a very Strong acid (JCq = 1.3 X 10 ). Phenol is used industrially to make plastics and dyes, and as a topical anesthetic in throat sprays. 

Phenol is an aromatic alcohol with the properties of a weak acid (it has a labile H, which accounts for its acid character). Its three-dimensional stmcture tends to retain the H-l- ion from the hydroxyl group through a so-called mesomeric effect. It is sometimes called carbolic acid when in water solution. It reacts with strong bases to form the salts called phenolates. Its pKa is high, at 9.95. Phenol has antiseptic, antifungal, and anesthetic pharmacological properties. 

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