Benemid

Benemid is a prescription medication used to treat high uric acid levels associated with gout and gouty arthritis. Benemid belongs to a group of drugs called renal tubular blocking agents. For gout and gouty arthritis, it works on the kidneys to help the body get rid of uric acid. It increases the effectiveness of antibiotics by preventing the body from eliminating them in the urine.

This medication comes as a tablet to take by mouth and is usually taken twice a day, with food, for gout and gouty arthritis. Benemid should be taken with plenty of water.

Common side effects of Benemid include headache, vomiting, nausea, and loss of appetite.

Benemid can also cause dizziness. Do not drive or operate heavy machinery until you know how Benemid affects you.

Dosage Forms & Strengths

tablet

• 500mg

Gout

250 mg PO twice daily for 1 week; increase to 500 mg PO twice daily to 2 g/day maximum with dosage increases of 500 mg q4weeks

If gout attacks do not occur for 4 months and uric acid levels are within normal may reduce dose by 500 mg q6monts

Prolong Penicillin Serum Levels

500 mg PO four times daily

Pelvic Inflammatory Disease

1 g PO with 2 g cefoxitin IM as single dose

Gonorrhea

1 g PO with 2 g cefoxitin IM as single dose

Renal Impairment

CrCl<30 mL/min: Avoid use

Dosage Forms & Strengths

tablet

• 500mg

Prolong Penicillin Serum Levels

<2 years old

• Contraindicated

>2 years old

• <45 kg: Load 25 mg/kg PO once with PCN; increase to 40 mg/kg/day PO divided q6hr; not to exceed 500 mg/dose 
• >45 kg: 500 mg PO four times daily

Gonorrhea

<50 kg

• Safety and efficacy not established

>50 kg

• 1 g PO with 2 g cefoxitin IM as single dose

Contraindications

<2 years

Uric acid kidney stones, acute gouty arthritis

Hypersensitivity

Blood dyscrasias

Small or large dose aspirin therapy

Cautions

PUD, renal impairment (CrCl <50 mLmin)

Do NOT administer for acute gouty attacks; if acute precipitation occurs during treatment may continue therapy

Alkalinize urine to avoid renal calculi

Use caution in patients with G6PD deficiency; may increase risk for hemolytic anemia

Discontinue if allergic reaction occurs

Use caution in patients with peptic ulcer disease

May cause exacerbation of acute gouty attack

Monotherapy may not be effective in patients with a creatinine clearance <30 mL/min

May increase serum concentration of methetrexate (avoid concomitant administration)

Use of probenecid with penicillin in patients with with renal insufficiency is not recommended

Salicylates may reduce the therapeutic effects of probenecid (effect may be pronounced with high chronic doses

Pregnancy Category: B

Lactation: Not known if distributed into breast milk, use with caution

Pregnancy Categories

A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA:Information not available.

You should not use this medication if you are allergic to probenecid, or if you have uric acid kidney stones, a gout attack that has already started, or a blood cell disorder such as anemia, or decreased white blood cells. Probenecid should not be given to a child younger than 2 years old.

Before taking probenecid, tell your doctor if you are allergic to any drugs, or if you have kidney disease, a history of stomach ulcer, or if you have ever had kidney stones.

Drink plenty of water to prevent kidney stones while you are taking probenecid.

Probenecid may be only part of a complete program of treatment that also includes diet, other medications, and mineral supplements. Follow your doctor's instructions.

Call your doctor at once if you have worsening gout symptoms, severe pain in your side or lower back, blood in your urine, swelling, fever, pale or yellowed skin, or dark-colored urine.

Gout:
-Chronic renal insufficiency (CrCl less than 30 mL/min): Not recommended as it may not be effective
-Renal impairment: Use caution; dosage requirements may be increased in some patients with some renal impairment

Adjunct to penicillin:
-Not recommended in conjunction with penicillin in the presence of known renal impairment.
-If used in elderly patients with renal impairment, use caution, dose reduction may be warranted, specific guidelines are not provided

Gout:
-Chronic renal insufficiency (CrCl less than 30 mL/min): Not recommended as it may not be effective
-Renal impairment: Use caution; dosage requirements may be increased in some patients with some renal impairment

Adjunct to penicillin:
-Not recommended in conjunction with penicillin in the presence of known renal impairment.
-If used in elderly patients with renal impairment, use caution, dose reduction may be warranted, specific guidelines are not provided

Administration advice:
Take orally

Gout:
-Maintain adequate hydration (at least 2 L/day) and alkalization of the urine with sodium bicarbonate or potassium citrate as needed.

Storage requirements:
-Protect from light

General:
-Gastric intolerance may be indicative of toxicity and can be corrected by decreasing dosage.
-This drug should not be started until an acute gouty attack has subsided; if an acute attack is precipitated during therapy, this drug should be continued at same dose while appropriate therapy is given to control acute attack.
-This drug inhibits the tubular secretion of penicillin and usually increases penicillin plasma levels 2 to 4 fold.

Monitoring:
Gout:
-Monitor serum urate levels as needed to determine adequacy of treatment
-Monitor acid-base balance in patients administered alkali.

Patient advice:
-Instruct patients on the need for adequate hydration, alkalization of the urine, and/or dietary restrictions appropriate to their care.
-Inform patients that salicylates may diminish the uricosuric effect of this drug; if a mild analgesic agent is needed, acetaminophen should be used.

Summary of Use during Lactation

Limited information indicates that maternal doses of probenecid up to 2 grams daily produce low levels in milk and would not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months. In animal studies, probenecid increased the breastmilk excretion of cimetidine, possible via an interaction with an active transport mechanism in the breast.[1] The implications of enhanced excretion of drugs given with probenecid for nursing mothers and their infants has not been studied; however, only a few drugs are known to undergo active transport into breastmilk.

Drug Levels

Maternal Levels. A woman was given probenecid 500 mg orally 4 times daily to enhance cephalexin serum levels. After 16 days of therapy at 4.5 weeks postpartum, 12 samples of breastmilk (6 pairs of fore- and hindmilk) were collected over a 16-hour period. The average concentration of probenecid in milk was 964 mcg/L, corresponding to an infant dosage of 145 mcg/kg daily and 0.7% of the maternal weight-adjusted dosage.[2]

Infant Levels. Relevant published information was not found as of the revision date.

Effects in Breastfed Infants

A woman with mastitis received 3 days of intravenous cephalothin, followed by 16 days of probenecid 500 mg and cephalexin 500 mg 4 times daily for 16 days. Her infant developed green liquid stools, severe diarrhea, discomfort and crying. The authors judged the effects to be probably related to the cephalothin and cephalexin in milk rather than the probenecid.[2]

Effects on Lactation and Breastmilk

Relevant published information was not found as of the revision date.

References

1. Gerk PM, Oo CY, Paxton EW et al. Interactions between cimetidine, nitrofurantoin, and probenecid active transport into rat milk. J Pharmacol Exp Ther. 2001;296:175-80. PMID: 11123378

2. Ilett KF, Hackett LP, Ingle B, Bretz PJ. Transfer of probenecid and cephalexin into breast milk. Ann Pharmacother. 2006;40:986-9. PMID: 16551765

LactMed Record Number

507

Last Revision Date

20130907

Disclaimer

Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.