Probenecid Quinolones

PROBENECID QUINOLONES -CIPROFLOXACIN, LEVOFLOXACIN, NALIDIXIC ACID, NORFLOXACIN t ciprofloxacin, nalidixic acid and norfloxacin levels Uncertain Watch for t incidence of side-effects. Moxifloxacin, ofloxacin and sparfloxacin do not seem to interact and could be used as alternative therapy... 

Ciprofloxacin (Cipro, Cipro XR, Proquin XR) [Antibiotic/ Fluoroquinolone] Uses Rx lower resp tract, sinuses, skin skin structure, bone/joints, urinary tract Infxns including prostatitis Action Quinolone antibiotic DNA gyrase Dose Adults. 250-750 mg PO ql2h XR 500-1000 mg PO q24h or 200-400 mg IV ql2h in renal impair Caution [C, /-] Children <18 y Contra Component sensitivity Disp Tabs, susp, inj SE Restlessness, N/V/D, rash, ruptured tendons, T LFTs Interactions T Effects Wf probenecid T effects OF diazepam, theophylline, caffeine, metoprolol, propranolol, phenytoin, warfarin effects W/ antacids, didanosine, Fe salts. Mg, sucralfate, Na bicarbonate,... 

Un, acute exacerbation of chronic bronchitis prophylaxis in transurethral procedures Action Quinolone antibiotic -1- DNA gyrase. Dose 400 mg/d PO X w/ renal insuff, avoid antacids Caution [C, —] Interactions w/ cation-containing products Contra Quinolone all gy, children <18 y,T QT interval, X Disp Tabs SE NA/ /D, abd pain, photosens, Szs, HA, dizziness, tendon rupture, periph al neuropathy, pseudomembranous cohtis, anaphylaxis Interactions t Effects W/ cimetidine, probenecid T effects OF cyclosporine, warfarin, caffeine X effects W/ antacids EMS Monitor ECG for TqT int val, esp in pts taking class lA/III antiarrhythmics monitor ECG and BP for signs of h5 povolemia and electrol5rte disturbances (hypokalemia) d/t D T risk of photosensitivity Rxns OD May cause NA /D, confusion and Szs symptomatic and supportive... 

Renal elimination is by glomerular filtration and active tubular secretion, which can be blocked by probenecid. As noted in Table 2, urinary recovery of the quinolones is variable. The antibacterial activity of these compounds is reduced at low urinary pH [215]. 

Nitrofurantoin (Macrodanrin, Furadanrin, Macrobid) [Urinary Anri-infective] WARNING Pulm Rxns possible Uses Prevendon Rx UTE Action Bacteriostatic iaterferes w/ carbohydrate metabolism. Dose Adults. Suppression 50-100 mg/d PO Rx 50-100 mg PO qid Peds. Suppression 1-2 mg/kg/d ia 1—2 + doses, max 100 mg/d Rx 5—7 mg/lcg/24 h ia 4 + doses (w/ food/milk/antacid) Caution [B, +] Avoid w/ CrCl <60 ml ymin, PRG at term Contra Renal failure, infants <1 mo Disp Cperipheral neuropathy Interactions T Effects W/ probenecid, sulfinpyrazone 4 effects w/ antacids, quinolones EMS May affect glucose (hypoglycemia) may discolor urine OD May cause N/V give IV fluids... 

Cephalosporins Dapsone Methotrexate Penicillins Quinolones Probenecid Serum levels of drug affected raised possibility of toxicity with some drugs... 

The likely explanation for this interaction is that probenecid successfully competes with some quinolones for tubular excretion, so that their renal elimination is reduced. Some quinolones are more dependent on glomerular filtration (e.g. grepafloxacin) than tubular excretion for elimination, and thus are unaffected by competition for tubular excretion. ... 

The increased levels and decreased renal excretion of clinafloxacin caused by probenecid are not considered large enough to warrant dosage adjustment," and most of the changes seen with the other quinolones were of a similar magnitude. However, caution has been advised in the presence of other drugs that may also compete for renal excretion (such as some penicillins or cephalosporins). " Grepafloxacin, moxifloxacin, sparfloxacin, and probably ofloxacin, appear not to interact. 

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