[Azapropazone plasma levels under simultaneous treatment with an antacid or laxative]

Azapropazone is a non-steroid antirheumatic drug, commonly used in long-term treatment of inflammatory and non-inflammatory rheumatic diseases. Since antacids and laxatives are often taken simultaneously the present study was concerned with the influence of a concomitant treatment with medium doses of dihydroxy-aluminium sodium carbonate, magnesium aluminum silicate, bisacodyl and anthraquinone cathartics on steady-state plasma levels of azapropazone when azapropazone was given as an oral dose 3 times daily to 15 patients. Azapropazone plasma levels were determined 5 h after azapropazone administration by a direct quantitative thin-layer chromatographic method. Azapropazone plasma levels during simultaneous treatment with antacids were 70.3 +/- 14.1 microgram/ml in comparison to 75.4 +/- 16.5 microgram/ml after azapropazone alone (p = 0.10). After the administration of the laxatives a mean plasma concentration of 68.2 +/- 10.1 microgram/ml was obtained, without laxative the average plasma level of azapropazone accounted for 65.1 +/- 8.1 microgram/ml (p greater than 0.05). There were virtually no effects of simultaneous treatment on azapropazone plasma levels. The results suggest that azapropazone can be given together with antacids and laxatives since there is no significant interaction.