Salicylic acid toxicity

Salicylism, or salicylic acid toxicity, is characterized by rapid breathing, tinnitus, hearing loss, dizziness, abdominal cramps, and central nervous system reactions. It has been reported with 20% salicylic acid applied to 50% of the body surface, and it has also been reported with use of 40 and 50% salicylic acid paste preparations [7]. The author has peeled more than 1,000 patients with the current 20 and 30% marketed ethanol formulations and has observed no cases of salicylism. 

S alleylism, or salicylic acid toxicity, is characterized by rapid breathing, tinnitus, hearing loss, dizzi-... 

Most published examples of prodrugs of relevance in the present context contain an a-amino acyl moiety. A number of reasons may explain this fact, such as the lack of toxicity of these natural compounds, the large differences in lipophilicity and other properties between amino acids, and the variability afforded by A-substituents. Interesting examples are provided by salicylic acid and metronidazole. Thus, the hydrolysis of tyrosine and methionine prodrugs of salicylic acid (8.104 and 8.105, respectively) was examined in rabbits after intraduodenal and intracecal administration [134], The former ester, but not the latter, was hydrolyzed in the mucosa of the small intestine. In addition, both prodrugs underwent marked hydrolysis by intestinal microflora. 

Phytohormones such as ethylene, salicylic acid (SA), JA, and abscisic acid (ABA) regulate responses of plants to stresses via action referred as signaling crosstalk. Moreover, reactive oxygen species (ROS), the toxic byproducts of aerobic metabolism, play the important role of signaling molecules. Usually, the defensive responses of plants depend on the interaction (positive or negative) between phytohormone signaling pathways rather than on the independent contribution of each of them. " ... 

Benzoic acid with salicylic acid is useful as an antifungal agent against various types of dermatophy-toses. The combination also has keratolytic properties. Salicylic acid may cause mild irritation of the skin. If applied to large areas of the body, amounts sufficient to cause toxicity may be absorbed. 

Salicylism and death have occurred following topical application. In an adult, 1 g of a topically applied 6% salicylic acid preparation will raise the serum salicylate level not more than 0.5 mg/dL of plasma the threshold for toxicity is 30-50 mg/dL. Higher serum levels are possible in children, who are therefore at a greater risk for salicylism. In cases of severe intoxication, hemodialysis is the treatment of choice (see Chapter 58). It is advisable to limit both the total amount of salicylic acid applied and the frequency of application. Urticarial, anaphylactic, and erythema multiforme reactions may occur in patients who are allergic to salicylates. Topical use may be associated with local irritation, acute inflammation, and even ulceration with the use of high concentrations of salicylic acid. Particular care must be exercised when using the drug on the extremities of patients with diabetes or peripheral vascular disease. 

Certain foreign compounds can cause changes in body temperature, which may become a toxic response if they are extreme. Substances such as 2,4-dinitrophenol and salicylic acid will raise body temperature, as they uncouple mitochondrial oxidative phosphorylation. Thus, the energy normally directed into ATP during oxidative phosphorylation is released as heat. Substances that cause vasodilation may cause a decrease in body temperature. 

Salicylic acid is mainly responsible for the toxic effects of aspirin, and it has a number of metabolic and physiological effects some of which are interrelated (Fig. 7.58) ... 

The 2-hydroxybenzoic acid, normally called salicylic acid, is well known due to its medical applications, namely as an antipyretic and in the treatment of certain types of rheumatism. The biological action of this compound is connected4,5 with its ability to bind metal ions. Not only is the efficacy of the treatment increased, but toxicity problems related to the injection of salicylic acid are diminished by administering salicylate metal complexes. 

Salicylism and death have occurred following topical application. In an adult, 1 g of a topically applied 6% salicylic acid preparation will raise the serum salicylate level not more than 0.5 mg/dL of plasma the threshold for toxicity is 30-50 mg/dL. Higher serum levels are possible in children,... 

There are two solid organic compounds listed in Table 1, phenol and salicylic acid. Phenol is a low melting (41-43°C) solid with a high vapor pressure. It is a severe skin irritant in addition to being highly toxic and potentially teratogenic. Since it is normally dispensed as a liquid (with a little water), phenol is listed with the organic liquids in Table 2. 

Toxicity. The estimated minimum lethal dose is 15 g. Plasma concentrations of salicylic acid greater than 300 pg/ml are likely to produce toxic reactions and concentrations greater than 500 pg/ml are associated with moderate to severe intoxication. The maximum permissible atmospheric concentration is 5 mg/m. ... 

Toxicity. Methyl salicylate is more toxic than salicylic acid. Deaths have occurred in children after ingestion of as little as 4 ml and doses of 30 ml are usually fatal in adults. 

Many currently used drugs like acetyl salicylic acid, digitalis, nitrates, and quinine have existed for a long time, and so have many poisons like cyanide and neurotoxins. However, their mechanism of action was not known until the middle of 20th century or even later. CO is unique. The details of its mechanism of toxicity were published by Haldane as early as 1895 and subsequent work has only elaborated these details while affirming its correctness. The generation of COHb is the principal cause of CO toxicity however, it is not the only one. Much research has been done to elaborate these additional mechanisms of CO... 

SAFETY PROFILE Moderately toxic by ingestion. See also BENZYL ALCOHOL, SALICYLIC ACID, and ESTERS. Combustible when exposed to heat or flame. When heated to decomposition it... 

Many of the chemicals used in this course will be unfamiliar to you. Their properties can be looked up in reference books, a very useful one being the Aldrich Catalog Handbook of Fine Chemicals. It is interesting to note that 1,4-dichlorobenzene is listed as a toxic irritant and naphthalene is listed as an irritant. Both are used as moth balls. Camphor, used in vaporizers, is classified as a flammable solid irritant. Salicylic acid, which we will use to synthesize aspirin (Chapter 26) is listed as moisture-sensitive toxic. Aspirin (acetylsalicyclic acid) is classified as an irritant. Caffeine, which we will isolate from tea or cola syrup (Chapter 8), is classified as toxic. Substances not so familiar to you—1-naphthol and benzoic acid—are classified respectively as toxic irritants and irritant. To put things in some perspective, nicotine is classified as highly toxic. ... 

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