Salicylates Carbonic anhydrase inhibitors

Dorzolamide (Trusopt) [Carbonic Anhydrase Inhibitor, Sul-fonamide/Glaucoma A9ent] Uses Glaucoma Action Carbonic anhydrase inhibitor Dose 1 gtt in eye(s) tid Caution [C, ] Contra Component sensitivity Disp Soln SE Irritation, bitter taste, punctate k atitis, ocular all gic Rxn EMS t Effects W/ oral carbonic anhydrase inhibitors, salicylates EMS Drug is absorbed systemicaUy OD May cause electrolyte disturbances (K) and acidosis monitor ECG... 

Food containing salicylate (curry powder, paprika, licorice, prunes, raisins, and tea) may increase the risk of adverse reactions. Coadministration of the salicylates with activated charcoal decreases the absorption of the salicylates. Antacids may decrease the effects of the salicylates. Coadministration with the carbonic anhydrase inhibitors increases the risk of salicylism. Aspirin may increase the risk of bleeding during... 

Drugs that may interact with carbonic anhydrase inhibitors include cyclosporine, primidone, salicylates, and diflunisal. 

Hypersensitivity to sulfonamides or chemically related drugs (eg, sulfonylureas, thiazide and loop diuretics, carbonic anhydrase inhibitors, sunscreens with PABA, local anesthetics) pregnancy at term lactation infants less than 2 months of age (except in congenital toxoplasmosis as adjunct with pyrimethamine) porphyria salicylate hypersensitivity. 

Sulfasalazine is contraindicated in individuals with hypersensitivity to salicylates, sulfonamides, sulfonylureas, and certain diuretics (furosemide, thiazides, and carbonic anhydrase inhibitors). Because it can cause kernicterus, sulfasalazine is contraindicated in infants and children under 2 years of age. Sulfasalazine passes into breast milk and is therefore contraindicated for nursing mothers. Similarly, pregnant women near term should not use this drug, although it appears to be the safest of the DMARDs during early pregnancy. 

Carbonic anhydrase inhibitors [NE] Increased acetazolamide serum concentrations increase salicylate toxicity due to decreased blood pH. 

Salicylates Interference with renal excretion of drugs that undergo active tubular secretion. Salicylate renal excretion dependent on urinary pH when large doses of salicylate used. Aspirin (but not other salicylates) interferes with platelet function. Large doses of salicylates have intrinsic hypoglycemic activity. Salicylates may displace drugs from plasma protein binding sites. Carbonic anhydrase inhibitors [NE] Increased acetazolamide serum concentrations increased salicylate toxicity due to decreased blood pH. 

ASPIRIN CARBONIC ANHYDRASE INHIBITORS t risk of salicylate toxicity with high-dose aspirin Uncertain at present Use low-dose aspirin... 

Cowan RA, Hartnell GG, Lowdell CP, Baird IM, Leak AM. Metabolic acidosis induced by carbonic anhydrase inhibitors and salicylates in patients with normal renal function. BMJ (Chn Res Ed) 1984 289(6441) 347-8. 

Carbonic anhydrase inhibitors should be used with caution in patients with respiratory acidosis or those with severe loss of respiratory capacity, and in patients with diabetes mellitus. They are contraindicated in patients with hepatic disease or insufficiency, reduced serum concentrations of sodium or potassium, adrenocortical insufficiency, hyperchloremic acidosis, or severe renal disease or dysfunction. They should also be avoided in patients taking salicylates. 

Aspirin or other Salicylates + Carbonic anhydrase inhibitors... 

A severe and even life-threatening toxic reaction can occur in patients taking high-dose salicylates if they are given carbonic anhydrase inhibitors (acetazolamide, diclofenamide). 

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. ... 

Hurwitz GA Wingfield W, Cowart TD, Jollow DJ. Toxic interaction between salicylates and a carbonic anhydrase inhibitor the role of cerebral edema. Vet Hum Toxicol (1980) 22 (Siq)pl),... 

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