Oxolonic acid

D. Nalidixic, Pipemidic, and Oxolonic Acids I. Physicochemical and Pharmacologic Properties... 

Oxolonic acid is in vitro more efficient than nalidixic acid. The therapeutic mechanism is in this case too thought to be inhibition of bacterial DNA synthesis. The optimal action is in the range of pH 6.5-8. The half-life in serum is 2 /2-3 h. After oral administration of 4 x 240 mg oxolonic acid to human subjects, serum concentrations of 1.8 pg/ml and average 24-h-urine concentrations of 40 pg/ml are reached. 

Gopinathan (1973) thinks that the intracranial hypertension during nalidixic acid therapy is due to decreased absorption of cerebrospinal fluid. The range of side effects after oxolonic acid seems to be wider on the whole than after nalidixic acid nausea, vomiting, diarrhoea, spasms of the stomach, cardiopulmonary and neurological symptoms, and insomnia are prominent (Simon and Chermat 1977). Other less frequent adverse reactions to oxolonic acid are fever, rash, photosensitivity, palpitations, and a sense of tightness in the chest (Silverman 1981). Oxolonic acid should be given with food or antacids to minimize its side effects. 

Skin tests are not important in allergy to nalidixic, pipemidic, oxolonic acids. 

Nalidixic, Pipemidic and Oxolonic Acid-Speciflc Antibodies... 

Brehm and Korting (1970) had a positive consumption test with cutis extract, but consumption tests with epidermis, vessels, and thymic nuclei were negative. The consumption test by Steffen demonstrates incomplete antibodies. Therefore there is evidence that the bullous nalidixic acid reaction of the skin is an allergic phenomenon with incomplete antibodies against cutis. Routine demonstration of antibodies against nalidixic, pipemidic, and oxolonic acids are not usual. 

Routine lymphocyte transformation tests for nalidixic, pipemidic, and oxolonic acids are not usual, but may be helpful if more than one potential sensitizing medicament has been given. The clinical impression that phototoxic reactions to nalidixic acid are not related to specific antibodies is supported by negative lymphocyte transformation tests (Alexander and Forman 1971). 

A search through the literature has revealed no reports of experimental studies in animals concerning allergy to nalidixic, pipemidic or oxolonic acid. 

Gastric mucosal injury and occult blood loss can be reduced, but not prevented by the use of buffered effervescent, slow-release and enteric coated preparations of aspirin (79>, 82, 83=, 88=, 117=-119=, 120, 121). The presence of particulate aspirin is thought to be important, but aspirin and salicylic acid given in solution produced multiple lesions in rats (122). Even parenteral aspirin produces and enhances gastric mucosal lesions and bleeding (123). Carben-oxolone does not prevent the fall in gastric mucosal potential difference produced by aspirin in man (110=). 

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