Also Aspirin

See also Aspirin and Salicylic Acid and Related Compounds. 

High Pressure Liquid Chromatography. In plasma aspirin, salicylic acid, and salicyluric acid, sensitivity 50ng/ml for aspirin in plasma also aspirin metabolites in urine, UV detection—J. N. Buskin eta/., Clin. Chem., 1982,28,1200-1203. In plasma or urine aspirin and its major metabolites, detection limits in plasma lOOng/ml for aspirin and salicyluric acid, 500 ng/ml for salicylic acid, and 200 ng/ml for gentisic acid, UV detection—R. H. Rumble et a/., J. Chromat., 1981,225 Biomed. AppL, 14, 252-260. 

Nivaud-Guemet, E. Guemet, M. Ivanovic, D. Medenica, M. Effect of eluent pH on the ionic and molecular forms of the non-steroidal anti-inflammatory agents in reversed-phase high-performance liquid chromatography. J.Liq.Chromatogr, 1994, 17, 2343-2357 [also aspirin, flufenamic acid, keta-zone, mefenamic acid, niflumic, niflumic acid, nixylic acid, oxyphenbutazone, phenacetin, salicylamide, salicylic acid, sulfinpyrazone]... 

Smigol, V. Svec, R Frechet, J.M.J. Novel uniformly sized polymeric stationeuy phase with hydrophilized large pores for direct injection HPLC determination of drugs in biological fluids. J.Liq.Chromatogr, 1994, 17, 891-911 [direct injection cow plasma also aspirin, caffeine, carbamazepine, lidocaine, salicylic acid, theobromine, theophylline]... 

Direct information seems to be limited to this study but what occurred is consistent with the way indometacin reduces the effects of many other different antihypertensives (e.g. see ACE inhibitors + NSAIDs , p.28, and Beta blockers + Aspirin or NSAIDs , p.835). It apparently does not affect every patient. If indometacin is added to established treatment with prazosin, be alert for a reduced antihypertensive response. It is not known exactly what happens in patients taking both drugs long-term, but note that with other interactions between antihypertensives and NSAIDs the effects seem to be modest. The manufacturers say that prazosin has been given with indometacin (and also aspirin and phenylbutazone) without any adverse interaction in clinical experience to date. Other manufacturers also... 

Not fully established. One idea is that these carbonic anhydrase inhibitors (acetazolamide, diclofenamide) affect the plasma pH, so that more of the salicylate exists in the un-ionised (lipid-soluble) form, which can enter the CNS and other tissues more easily, leading to salicylate toxicity. However, carbonic anhydrase inhibitors also make the urine more alkaline, which increases the loss of salicylate (see also Aspirin or other Salicylates + Antacids , p.l35). Animal studies confirm that carbonic anhydrase inhibitors increase the lethal toxicity of aspirin. An alternative suggestion is that because salicylate inhibits the plasma protein binding of acetazolamide and its excretion by the kidney, acetazolamide toxicity, which mimics salicylate toxicity, may occur. ... 

Consider also Aspirin or other Salicylates + Corticosteroids or Corticotropin , p.l36. 

The uricosuric effects of sulfinpyrazone are not opposed by the concurrent use of flufenamic acid, meclofenamic acid or mefenamic acid. Consider also Aspirin or other Salicylates + Sulfinpyrazone , p.l38). 

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