Probenecid Sulfonylureas

Drugs that may affect aspirin include activated charcoal, ammonium chloride, ascorbic acid or methionine, antacids and urinary alkalinizers, carbonic anhydrase inhibitors, corticosteroids, and nizatidine. Drugs that may be affected by aspirin include alcohol, ACE inhibitors, anticoagulants (oral), beta-adrenergic blockers, heparin, loop diuretics, methotrexate, nitroglycerin, NSAIDs, probenecid and sulfinpyrazone, spironolactone, sulfonylureas and exogenous insulin, and valproic acid. 

Drugs that may be affected by probenecid include acyclovir allopurinol barbiturates benzodiazepines clofibrate dapsone dyphylline methotrexate NSAIDs pantothenic acid penicillamine rifampin sulfonamides sulfonylureas zidovudine salicylates. 

Uses Edema, HTN, CHF, h atic cirrhosis Action Loop diuretic -1- reabsorption of Na Cr in ascending loop of Henle distal tubule Dose 5-20 mg/d PO or IV 200 mg/d max Caution [B, ] Contra Sulfonylurea sensitivity Disp Tabs, inj SE Orthostatic -1- BP, HA, dizziness, photosens, electrolyte imbalance, blurred vision, renal impair Notes 20 mg torsemide = 40 mg furosemide Interactions t Risk of ototox W/ aminoglycosides, cisplatin t effects W/ thiazides t effects OF anticoagulants, antih5rpCTtensives, Li, salicylates X effects IT/barbiturates, carbamaz ine, cholestyramine, NSAIDs, phenytoin, phenobarbital, probenecid, dandehon EMS t Effects of anticoagulants monitor for S/Sxs tinnitus, monitor ECG for hypokalemia (flattened T waves) OD May cause HA, hypotension, hypovolemia, and hypokalemia give IV fluids symptomatic and supportive... 

Probenecid can impair the renal active secretion of a variety of acidic compounds, including sulfinpyrazone, sulfonylureas, indomethacin, penicillin, sulfonamides, and 17-ketosteroids. If these agents are to be given concomitantly with probenecid, their dosage should be modified appropriately. Salicylates interfere with the clinical effects of both sulfinpyrazone and probenecid and should be avoided in patients treated with uricosuric agents. Uricosuric agents also can influence the volume of distribution and hepatic metabolism of a number of drugs. 

Nonsteroidal anti-inflammatory drugs (naproxen and ibuprofen) Penicillins Phenylbutazone Probenecid Salicylates Sulfonamides Barbitu rates Phenytoin Probenecid Retinoids Salicylates Sulfonamides Sulfonylureas Tetracycline Ethanol Retinoids Dipyridamole... 

On the other hand, probenecid increases the plasma level of acyclovir, allopurinol, barbiturate, benzodiazepines, clof-ibrate, dapsone, dyphylline, methotrexate, NSAIDs, penicillamine, sulfonylureas, and zidovudine. 

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