Acetylsalicylic acid sensitivity

A major aim of enteric coating is protection of drugs that are sensitive or unstable at acidic pH. This is particularly important for drugs such as enzymes and proteins, because these macromolecules are rapidly hydrolyzed and inactivated in acidic medium. Antibiotics, especially macrolide antibiotics like erythromycin, are also rapidly degraded by gastric juices. Others, such as acidic drugs like NSAID s (e.g., diclofenac, valproic acid, or acetylsalicylic acid) need to be enteric coated to prevent local irritation of the stomach mucosa. 

Ketorolac tromethamine is contraindicated in patients while wearing soft contact lenses. Caution should be used with patients who have previously exhibited sensitivity to acetylsalicylic acid,phenylacetic acid derivatives, and other NSAIDs because a potential exists for cross-sensitivity. 

People with asthma may be particularly sensitive to acetylsalicylic acid, which may be given alone or as a constituent of a combination medicine. The association between aspirin sensitivity, nasal polyps, and rhinitis in asthma is well known. 

Avoid strictly acetylsalicylic acid or other non-steroidal anti-inflammatory drugs in patients who have been diagnosed to be sensitive to them (C). 

The phase-transfer principle has likewise been applied to alkylation of carboxy-late salts [212]. Acids sensitive to hydrolysis, like acetylsalicylic acid, were found to react with alkyl iodides after neutralization with tetrabutylammonium bicarbonate in methylene chloride. 

Psoriasis preparations may contain salicylic acid, a rare sensitizer (five cases (Rudzki and Koslowska 1976). Four of the patients used salicylic acid 2% in alcohol. They tolerated oral acetylsalicylic acid (aspirin) without causing exacerbation or relapse of the dermatitis. 

Example The negative-ion DESI mass spectrum of the over-the-counter drug acetylsalicylic acid (aspirin) was measured with a home-built DESI source attached to a seasoned triple quadrupole instrument (Fig. 13.5). The sarrple was presented on paper to a methanol spray. Whereas this sample even allowed tandem mass spectra of the [M-H]" ion, m/z 179, to be readily obtained, other samples were beyond the instrument s sensitivity limits [15]. 

Schlumberger, H. D., Lobbecke, F. A. and Kal-16s, P. (1974) Acetylsalicylic acid intolerance. Lack of N-acetylsalicylic acid specific, skin-sensitizing antibodies in the serum of intolerant individuals. Acta med. scand., 196, 451. 

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