5-aminosalicylic add

Sulfasalazine (salicylazosulfapyxidine) is used in inflammatory bowel disease (see p. 649) in effect the sulfapyridine component acts as a carrier to release the active 5-aminosalicylic add in the colon (see also rheumatoid cirthritis, p. 292). 

De Broe ME, Stolear JC, Nouwen EJ, Elseviers MM. 5-Aminosalicylic add (5-ASA) and chronic tubulo-interstitial nephritis in patients with chronic inflammatory bowel disease is there a link Nephrol Dial Transplant 1997 12 1839-1841. 

D X V 1 1 Gl upset if taken on empty stomach. May cause reversible infertility in men. 35% absorbed in intestine. Remainder metabolized to 5-aminosalicylic add in colon. Patients should be told that this drug turns urine orange. 

Other Names Salicylic acid, 5-amino- 2-Hydroxy-5-aminobenzoic acid 3-Carboxy-4-hydroxy-aniline 5-ASA 5-Amino-2-hydroxybenzoic acid 5-Aminosalicylic add Asacol Asacolitin Asacolon Canasa Claversal Fisalamine Ipocol Lixacol Mesacol Mesalamine Mesalazine Mesasal NSC 38877 Pentasa Rowasa Salofalk Salozinal m-Aminosalicylic acid CA Index Name Benzoic acid, 5-amino-2-hydroxy-CAS Registry Number 89-57-6 Merck Index Number 5904 Chemical Structure... 

Hie major site of bacterial activity is the caecum where the anaerobic bacteria ferment substrates (e.g. soluble fibre) in a liquid mixture. The fermentation in the caecum produces a marked drop in the pH of the luminal contents. Hie low oxygen tension in the colonic lumen encomages reductive conditions and this principle has been used to deliver dmgs specifically to the colon in the treatment of ulcerative colitis. pH studies using a pH-sensitive radiotelemetry capsule in normal, ambulatory volunteers have shown that the mean pH in the colonic lumen is 6.4 0.6 in the ascending colon, 6.6 0.8 in the transverse colon and 7.0 0.7 in the descending colon. The azo-bond of sulfasalazine is cleaved by bacteria] azo-reductase activity to release the active component 5-aminosalicylic add (Fig. 8.54). 

Other Derivatives of SaUcylic Acid. p-Aminosalicylic acid and its salts have been used in the treatment of tuberculosis. / -Aminosalicylic add can be prepared by the caiboxylation of in-amiuoplienol. Metliylene-5,5-disalicylic acid, produced by heating two parts salicylic acid with 1-1.5 parts of 30-40 wt % formaldehyde in the presence of an add catalyst, is used as an intermediate in the production of bacitracin me thy le ne di salicy la te. 

Sulfasalazine is a pro-drug that is not active in its ingested form. It is broken down by colonic bacteria into 5-aminosalicylic acid (5-ASA mesalamine) and sulfapyridine. Some controversy exists regarding which of these two products are responsible for the activity of azulfidine. 5-Aminosalicylic acid, however, is known to have a therapeutic benefit, although it is not clear whether sulfapyridine adds any further benefit. In the colon, the products created by the breakdown of sulfasalazine work as anti-inflammatory agents for treating colon inflammation. The beneficiai effect of sulfasalazine is believed to result from a local effect on the bowel, although there also may be a beneficial systemic immune-suppressant effect. Sulfasalazine was approved in 1950. 

To 1 ml of urine add 5 drops of Trinder s reagent A violet colour indicates the presence of salicylate or salicyl-amide. A positive result is obtained after therapeutic doses of aspirin or aminosalicylic acid. 

Probes currently employed in the indirect UV detection of amino acids include p-aminosalicylic acid, benzoic acid, phthalic acid, sodium chromate, 4-(V,iV -dimethylamino)benzoic acid, 1,2,4,-benzenetricar-boxylic acid (trimellitic acid), 1,2,4,5-benzenetetracar-boxylic acid (pyromeUitic add), and quinine sulfate. Several of these probes are employed in combination with metal cations and cationic surfactants, which are incorporated into the electrolyte solution as modifiers of the electro-osmotic flow. 

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