How Do Uricosuric Agents Work?

Uricosuric agents are medications prescribed for the treatment of gout, a painful arthritic condition caused by excessive uric acid in the blood that gets deposited as monosodium urate crystals in joints. Gout most commonly affects the big toes, but can also affect other joints such as ankles, knees, elbows, wrists, and fingers.

Uricosuric agents work in the following ways to prevent joint inflammation caused by gout:

• Inhibit reabsorption (reuptake) of urate in the kidneys, thereby increasing its excretion in the urine.
• Prevent urate crystal-induced inflammatory response from the immune system by interfering with several cellular functions of immune cells that enable them to migrate to the joints and promote inflammation.

Uricosuric agents are also used as an adjunct treatment in some bacterial infections because they inhibit the secretion of certain antibiotics such as penicillin and cephalosporins by the kidneys and prolong their bioavailability.

Uricosuric agents are oral tablets approved by the FDA for use in the following conditions:

• Gout
• Chronic gouty arthritis complicated by frequent, recurrent gout attacks
• To prolong serum levels of antibiotics such as penicillin and cephalosporins in the treatment of:
  • Pelvic inflammatory disease
  • Gonorrhea

Side effects of uricosuric agents may include the following:

• Headache
• Dizziness
• Nausea
• Vomiting
• Anorexia (loss of appetite)
• Gastrointestinal (GI) upset
• Diarrhea
• Abdominal pain
• Sore gums
• Hypersensitivity reactions such as:
  • Rash
  • Urticaria (hives)
  • Pruritus (itching)
  • Dermatitis
  • Purpura (purple spots on the skin caused by small blood vessels bursting)
• Anaphylaxis (severe allergic reaction)
• Alopecia (hair loss)
• Flushing
• Fever
• Blood disorders such as:
  • Anemia (low red blood cell count)
  • Aplastic anemia (anemia due to reduced red cell production)
  • Hemolytic anemia (anemia from rapid destruction of red cells)
  • Leukopenia (low count of leukocytes, type of immune cells)
  • Agranulocytosis (low count of granulocytes, immune cells with granules)
• Generalized vascular damage
• Renal damage
• Hematuria (blood in the urine)
• Oliguria (low urine output)
• Renal calculi (kidney stones) with or without hematuria
• Nephrotic syndrome (kidney disorder that causes excessive excretion of protein in the urine), rare
• Renal colic and costovertebral pain (severe flank and upper back pain due to stone in the urinary tract)
• Urinary frequency
• Exacerbation of gout
• Gouty arthritis
• Hepatic necrosis (liver tissue death), rare
• Colchicine toxicity with liver dysfunction
• Peripheral neuritis (nerve inflammation)
• Muscular weakness

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of uricosuric agents include:

• colchicine/probenecid
• Col-probenecid
• probenecid
• Probalan