Probenecid Ceftriaxone

Levofloxacin 500 mg PO daily for 14 days with or without metronidazole 500 mg PO twice daily for 14 days Ceftriaxone 250 mg IM single dose and probenecid 1 g single dose, plus doxycycline 100 mg PO twice daily for 14 days with or without metronidazole, 500 mg PO twice daily for 14 days Third-generation cephalosporin plus doxycycline 100 mg PO twice daily for 14 days with or without metronidazole 500 mg PO twice daily for 14 days... 

Urinary excretion is the major elimination path for most cephalosporins. When prescribing cephalosporins to patients with renal failure, practitioners must consider dose reduction or dose interval extension (Table 45.2). Renal tubular secretion contributes to the elimination of some cephalosporins, and an increase in cephalosporin plasma concentrations may occur when probenecid blocks renal tubular secretion of cephalosporins. Biliary elimination is important for some cephalosporins. Cefmetazole, cefoperazone (Cefobid), cefoxitin, and ceftriaxone achieve biliary concentrations greater than those in plasma. After parenteral administration of cefoperazone, 70% of the dose appears in the bile within 24 hours. Practitioners should decrease the dose of cefoperazone when prescribing for patients with hepatic failure or biliary obstruction. Metabolism is not a major elimination path for most cephalosporins. Cefotaxime is one of the few cephalosporins having an active metabolite, desacetyl cefotaxime. 

Ceftriaxone (A) Clindamycin (A) Clofibrate (A) Dexamethasone (N) Diazepam (B) Diazoxide (A) Dicloxacillin (N) Digitoxin (N) Etoposide (N) Ibuprofen (A) Indomethacin (A) Nafcillin (A) Naproxen (A) Oxacillin (A) Phenylbutazone (A) Phenytoin (A) Probenecid (A) Salicylic acid (A) Sulfisoxazole (A) Teniposide (N) Thiopental (A) Tolbutamide (A) Valproic acid (A) Warfarin (A)... 

LeBel M, Paone RP, Lewis GP. Effect of probenecid on the pharmacokinetics of ceftriaxone. J Antimicrob Chemother 1983 12(2) 147-55. 

Stoeckel K, Trueb V, Dubach UC, McNamara PJ. Effect of probenecid on the elimination and protein binding of ceftriaxone. Eur J Clin Pharmacol 1988 34(2) 151-6. 

Renal clearance similar to penicillins, with active tubular secretion blocked by probenecid. Dose modification in renal dysfunction, except cefoperazone and ceftriaxone, which are largely eliminated in the bile. 

Erythromycin suspension 50 mg/kg/d p.o. in four divided doses for 14 days) Erythromycin suspension 50 mg/kg/d p.o. in four divided doses for 14 days Acute epididymo-orchitis Amoxicillin 3.0 g p.o., or ampicillin 3.5 g p.o., or aqueous procaine penicillin G 4.8 million units IM at two sites (each along with probenecid 1.0 g p.o.), or spectinomycin 2.0 g IM or ceftriaxone 250 mg IM followed by tetracycline 500 p.o. four times daily for 10 days or... 

Ceftriaxone 250 mg IM once or ciprofloxacin 500 mg p.o. once or norfloxacin 800 mg p.o. or cefuroxime axetil 1 g p.o. once plus probenecid 1 g or cefotaxime 1 g IM once or ceftizoxime 500 mg IM once plus Doxycycline 100 mg two times daily for 7 days or tetracycline 500 mg four times daily for 7 days... 

A) Oral bioavailability is affected by first-pass hepatic metabolism Only third-generation cephalosporins cross the blood-brain barrier Procaine penicillin G is the most commonly used intravenous form of the antibiotic Renal tubular reabsorption of beta-lactams is inhibited by probenecid Nafcillin and ceftriaxone are eliminated mainly via biliary secretion The mechanism of antibacterial action of cephalosporins involves (A) Inhibition of the synthesis of precursors of peptidoglycans Interference with the synthesis of ergosterol Inhibition of transpeptidation reactions Inhibition of beta-lactamases Binding to cytoplasmic receptor proteins... 

Cefotetin, ceftriaxone, ceftizoxime, tobnetm, etodolac, chlorpropamide, carboplatin, cisplatin, ibuprofen, oxaliplatin, piperacillin, probenecid, quinine, quinidine... 

The serum levels of many cephalosporins are raised by probenecid. Possible exceptions include ceforanide, ceftazidime, ceftriaxone and latamoxef. The rise in serum levels may possibly increase the risk of nephrotoxicity with some cephalosporins such as cefal-oridine and cefalotin. 

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