Probenecid Aspirin

Penicillins and cephalosporins Probenecid, aspirin Blocked excretion of /3-lactams Use if prolonged high concentration of /J-lactam desirable... 

Probenecid is a uricosuric agent that blocks the tubular reabsorption of uric acid, increasing its excretion. Because of its mechanism of action, probenecid is contraindicated in patients with a history of uric acid stones or nephropathy. Probenecid loses its effectiveness as renal function declines and should be avoided when the creatinine clearance is 50 mL/minute or less. Its uricosuric effect is counteracted by low aspirin doses, which many patients receive for prophylaxis of coronary heart disease. 

Drugs that may be affected by aspirin include ACE inhibitors, acetazolamide, anticoagulants, anticonvulsants (hydantoins, valproic acid), beta blockers, diuretics, methotrexate, NSAIDs, oral hypoglycemics, and uricosuric agents (probenecid, sulfinpyrazone). 

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. 

Concomitant use with NSAiDs - Ketorolac is contraindicated in patients currently receiving aspirin or other NSAIDs ketorolac also is contraindicated with the concomitant use of probenecid. 

Drugs that may affect penicillins include allopurinol, aminoglycosides (parenteral), aspirin, beta blockers, chloramphenicol, erythromycin, ethacrynic acid, furosemide, indomethacin, phenylbutazone, probenecid, sulfonamides, tetracycline, and thiazide diuretics. Drugs that may be affected by penicillins include aminoglycosides (parenteral), anticoagulants, beta blockers, chloramphenicol, cyclosporine, oral contraceptives, erythromycin, heparin, and vecuronium. 

Bismuth Subsalicylate (Pepto-Bismol) [Antidiarrheal/ Adsorbent] [OTC] Uses Indigestion, N, D combo for Rx of H. pylori Infxn Action Antisecretory anti-inflammatory E>o e Adults. 2 tabs or 30 mL PO PRN (max 8 doses/24 h) Feds. 3—6 y 1/3 tab or 5 mL PO PRN (max 8 doses/24 h) 5-9 y 2/3 tab or 10 mL PO PRN (max 8 doses/24 h) 9-72 y 1 tab or 15 mL PO PRN (max 8 doses/24 h) Caution [C, D (3rd tri), -] Avoid w/ renal failure Hx severe GI bleed Contra Influenza or chickenpox (T risk of Reye synd), ASA allergy (see Aspirin) Disp Chew tabs, caplets, Liq, susp SE May turn tongue stools black Interactions T Effects OF ASA, MTX, valproic acid effects OF tetracyclines i effects W/ corticosteroids, probenecid EMS Monitor for hypovolemia and electrolyte disturbances d/t D may darken tongue stool OD Similar to ASA OD V, tinnitus, metabolic acidosis activated charcoal may be effective... 

Methotrexate Aspirin, phenylbutazone, probenecid Delayed excretion Increased toxicity. 

Iopanoic acid is as potent a uricosuric agent as probenecid and this effect might explain some renal complications aspirin reduces the uricosuric effect but can also impair X-ray visualization because of competition at plasma protein-binding sites. Fluctuations of serum urate after oral cholecystography can interfere with diagnostic tests and even precipitate an attack of gout (578). 

Aspirin, salicylates, and thiazide diuretics should not be used with allopurinol. The dose of mercaptopurine should be reduced one-third or one-fourth when used with allopurinol. Acute poisoning of colchicine should be treated with gastric lavage and activated charcoal administration. Supportive maintenance measures for blood pressure and respiration should be provided. Probenecid is used by athletes to inhibit the urinary excretion of banned anabolic steroids.85... 

Correct choice = D. Acetaminophen does not antagonize the uricosuric agent probenecid and therefore may be used in patients with gout. Acetaminophen has little anti-inflammatory effect, but has analgesic and antipyretic activities equal to those of aspirin. It is the analgesic-antipyretic of choice for children with viral infections aspirin can increase the risk for Reye s syndrome in children. Acetaminophen is a suitable substitute for the analgesic and antipyretic effects of aspirin in those patients with gastric complaints. 

PROBENECID ANTIPLATELET AGENTS Aspirin possibly 1 efficacy of probenecid Uncertain Watch for poor response to probenecid... 

Drugs that carry a possible risk of haemolysis in some G6PD deficient subjects inclulde aspirin (when dose exceeds 1 g/d), menadione, probenecid, quini-dine chloroquine and quinine (both are acceptable in acute malaria). 

For a displacement interaction to become clinically important, a second mechanism usually operates sodium valproate can cause phenytoin toxicity because it both displaces phenytoin from its binding site on plasma albumin and inhibits its metabolism. Similarly aspirin and probenecid (and possibly other nonsteroidal anti-inflammatory drugs) displace the folic acid antagonist methotrexate from its protein-binding site and reduce its rate of active secretion by the renal tubules the result is serious methotrexate toxicity. 

Interference with active transport. Organic acids are passed from the blood into the urine by active transport across the renal tubular epithelium. Penicillin is mostly excreted in this way. Probenecid, an organic acid that competes successfully with penicillin for this transport system, may be used to prolong the action of penicillin when repeated administration is impracticable, e.g. in sexually transmitted diseases, where compliance is notoriously poor. Interference with renal excretion of methotrexate by aspirin, of zidovudine by probenecid and of digoxin by quinidine, contribute to the potentially harmful interactions with these combinations. 

Glucose 6-phosphate dehydrogenase deficiency (G-6-PD) Aspirin, BAL (dimercaprol), chloroquine, chloramphenicol, dapsone hydroxychloroquine, nalidixic acid, nitrofurantoin, primaquine, probenecid, quinine, quinidine, sulfonamides Hemolytic anemia... 

Penicillin Probenecid Sulfisoxazole Aspirin Sulfamethoxy pyridazine Warfarin Diflunisal Phenylbutazone ... 

In low dosages (up to 2 g/day), aspirin reduces urate excretion and blocks the effects of probenecid and other uricosuric agents (116). However, in 11 patients with gout, aspirin 325 mg/day had no effect on the uricosuric action of probenecid (117). In higher dosages (over 5 g/day), salicylates increase urate excretion and inhibit the effects... 

Harris M, Bryant LR, Danaher P, Alloway J. Effect of low dose daily aspirin on serum urate levels and urinary excretion in patients receiving probenecid for gouty arthritis. J Rheumatol 2000 27(12) 2873-6. 

Concomitant use of heparin and oral anticoagulants can increase the risk for bleeding due to the antiplatelet effect of aspirin. In addition, use with alcohol can increase the risk of Gl bleeding. / spirin displaces a number of drugs (e.g., tolbutamide, nonsteroidal anti-inflammatory drugs [NSAIDs], methotrexate, phenytoin, and probenecid) from protein binding sites in the blood. Corticosteroid use can reduce serum salicylate levels by increasing the clearance of aspirin. 

Clinically important, potentially hazardous interactions with aspirin, methotrexate, probenecid... 

Clinically important, potentially hazardous interactions with acitretin, aldesleukin, aminoglycosides, amiodarone, amoxicillin, ampicillin, aspirin, bacampicillin, bismuth, carbenicillin, chloroquine, cisplatin, cloxacillin, co-trimoxazole, dapsone, demeclocycline, dexamethasone, diclofenac, dicloxacillin, etodolac, etoricoxib, etretinate, fenoprofen, flurbiprofen, folic acid antagonists, haloperidol, hydrocortisone, ibuprofen, indomethacin, influenza vaccines, ketoprofen, ketorolac, lithium, magnesium trisalicylate, meclofenamate, mefenamic acid, methicillin, mezlocillin, minocycline, nabumetone, nafcillin, naproxen, NSAIDs, omeprazole, oxacillin, oxaprozin, oxytetracycline, paromomycin, penicillin G, penicillin V, penicillins, phenylbutazone, piperacillin, piroxicam, polypeptide antibiotics, prednisolone, prednisone, probenecid, procarbazine, rofecoxib, salicylates, salsalate, sapropterin, sulfadiazine, sulfamethoxazole, sulfapyridine, sulfasalazine, sulfisoxazole, sulindac, tazobactum, tenoxicam, tetracycline, ticarcillin, tolmetin, trimethoprim, vaccines... 

The symptoms of acute gout respond to anli-innammatory drugs suchasindomelh-acin. but it should be noted that these drugs have no direct effect on the serum urate level. Low-dose aspirin should be avoided as it inhibits renal urate excretion. Treatment must also be directed at the hyperuricaemia. Drugs such as probenecid which promote urate excretion can be used prophylactically. A diet which is low in purines and alcohol may be prescribed in an effort to reduce the plasma urate concentration. Allopurinol, a specific inhibitor of the enzyme xanthine oxidase which catalyzes the oxidation... 

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