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Probenecid ball-and-stick.png
Systematic (IUPAC) name
4-(dipropylsulfamoyl)benzoic acid
Clinical data
Trade names Probalan
AHFS/ monograph
MedlinePlus a682395
Legal status
Routes oral
Pharmacokinetic data
Protein binding 75-95%
Half-life 2-6 hours (dose: 0.5-1 g)
Excretion renal (77-88%)
CAS number 57-66-9 YesY
ATC code M04AB01
PubChem CID 4911
IUPHAR ligand 4357
DrugBank DB01032
ChemSpider 4742 YesY
UNII PO572Z7917 YesY
KEGG D00475 YesY
Chemical data
Formula C13H19NO4S 
Mol. mass 285.36 g/mol
 YesY (what is this?)  (verify)

Probenecid (Lannett's Probalan) is a uricosuric drug that increases uric acid excretion in the urine. It is primarily used in treating gout and hyperuricemia.

Probenecid was developed as an alternative to caronamide[1] to competitively inhibit renal excretion of some drugs, thereby increasing their plasma concentration and prolonging their effects.


Probenecid is primarily used to treat gout and hyperuricemia.

During World War II, probenecid was used to extend limited supplies of penicillin,[2] and is still used to increase antibiotic concentrations in serious infections. In one study, probenecid was shown to more than double blood concentrations of oseltamivir (trade name Tamiflu), an antiviral drug used to combat the flu, suggesting this property applies to antivirals, as well.[3]

It has also found use as a masking agent.[4]

Drug interactions[edit]

Some of the important clinical interactions of probenecid include those with captopril, indomethacin, ketoprofen, ketorolac, naproxen, cephalosporins, quinolones, penicillins, methotrexate, zidovudine, ganciclovir, lorazepam and acyclovir. In all these interactions, the excretion of these drugs is reduced due to probenecid.


In the kidneys, probenecid is filtered at the glomerulus, secreted in the proximal tubule and reabsorbed in the distal tubule.

Probenecid works by interfering with the kidneys' organic anion transporter (OAT), which reclaims uric acid from the urine and returns it to the plasma.[5] If probenecid (an organic acid) is present, the OAT binds preferentially to it (instead of to uric acid), preventing reabsorption of the uric acid. Hence, the urine retains more uric acid, lowering uric acid concentration in the plasma. (This is a good example of a medical usage for competition between substrates transported across cell membranes).

See also[edit]