Probenecid with antibiotics for cellulitis

Sounds like 'pro-ben-eh-sid'

Key points about probenecid with antibiotics

  • Probenecid is sometimes used together with antibiotics such as flucloxacillin and cefalexin.
  • Probenecid makes these antibiotics more effective at treating cellulitis by keeping the antibiotics in your body longer.
  • Find out how to take it safely and possible side effects.
Cellulitis on lower leg
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Probenecid is sometimes used together with some antibiotic capsules (eg, flucloxacillin and cefalexin) for the treatment of cellulitis. Probenecid acts on your kidneys to slow down the removal of the antibiotic from your body, keeping the antibiotic in your body longer. This makes these antibiotics more effective in treating the infection. The combination of probenecid with these antibiotic capsules can work just as well as taking intravenous (IV) antibiotics.

Note: Probenecid is not an antibiotic. It doesn't kill or stop the growth of bacteria (bugs). It must be used with antibiotics to treat an infection.


For cellulitis, taking antibiotic capsules with probenecid instead of antibiotic injections has many benefits

  • It's convenient: Antibiotic capsules are easier to take at home without the need for clinic visits or hospital admission.
  • It's more comfortable: Antibiotic capsules don't involve needles or intravenous (IV) lines, which can be uncomfortable or restrictive.
  • Lower risk of infection: Not having an injection helps to reduce the risk of infection at the injection site or in the blood stream.
  • Costs less: Antibiotic capsules are generally less expensive than IV treatments, as you won't need hospital stays or medical equipment to have the antibiotic.

In Aotearoa New Zealand probenecid is available as tablets (500 mg).

For cellulitis, your doctor may prescribe probenecid with antibiotics as follows:

  • flucloxacillin  2 capsules (1000 mg) AND probenecid 1 tablet (500 mg) three times a day for 5 days
  • OR
  • cefalexin 2 capsules (1000 mg) AND probenecid 1 tablet (500 mg) three times a day for 5 days.

 

Infographic showing how to take probenecid with antibiotics

 

Image credit: Healthify He Puna Wairoa


Each dose will be 2 antibiotic capsules AND 1 probenecid tablet, taken three times a day for 5 days.

  • Timing: Take each dose 3 times a day, at about the same time each day. Space your doses evenly through out the day. Ideally, these times are at least 6 hours apart, for example 8 am, 2 pm and 8 pm. 
  • You can take each dose with or without food: Taking it with food may help to reduce nausea (feeling sick).
  • Missed dose: If you forget to take your dose, take it as soon as you remember. But if it is nearly time for your next dose, just take the next dose at the right time. Don't take double the dose.
  • Finish the course: It's important to take the whole course for the number of days your doctor has told you to. Don't stop taking it, even if you feel better. If you stop the antibiotics too soon, the bacteria that are left will start to multiply again, and may cause another infection.

You should start to feel better within 24 hours of starting the antibiotics and probenecid, but the redness and swelling may take a few days to go away.

Here are some things to know when you're taking probenecid. Other things may be important as well, so ask your healthcare provider what you should know about.

  • Other medicines: Probenecid and antibiotics may interact with some medicines, herbal supplements and rongoā Māori. Please check with your doctor or pharmacist before starting treatment and before starting any new products.
  • Keep yourself hydrated: It's important to drink plenty of water while you're taking these medicines.


For cellulitis, as well as taking antibiotics, you can do other things

  • Get plenty of rest. This helps your body to fight the infection. If you have cellulitis on your leg, limit walking for the first few days.
  • Raise the affected body part on a pillow or chair as much as possible, ideally above the level of your heart. If your arm or hand is involved, use a sling when you're walking around. This helps reduce swelling and inflammation and promotes healing. Continue to do this for the first 72 hours at least.
  • Drink plenty of fluids to prevent dehydration.

Contact your healthcare provider if your cellulitis is getting worse, if you're feeling more unwell or if there's no improvement after 2 days on antibiotics.

Read more about how cellulitis is treated.

For the treatment of cellulitis, where antibiotics and probenecid are used together for only five days, you are unlikely to get ongoing side effects.

Side effects What should I do?
  • Feeling sick (nausea)
  • Upset stomach
  • Indigestion
  • Feeling sick (vomiting)
  • These are common when you first start treatment.
  • Try taking your medicines with food.
  • Tell your doctor if these bother you.
  • Diarrhoea (runny poo)
  • This should settle after a few days.
  • Drink plenty of fluids such as water or diluted juice to avoid dehydration.
  • Tell your doctor immediately if the diarrhoea gets worse, is ongoing, starts after you've completed your medicines or if you have diarrhoea with other symptoms such as abdominal pain, cramping and nausea (feeling sick).   
  • Headache or dizziness
  • Loss of appetite
  • Flushing
  • These are less common.
  • Tell your doctor if these bother you.
  • Signs of thrush such as vaginal itching, soreness or discharge (this can be thick and white or thin and watery, without any smell)
  • Tell your doctor, nurse or pharmacist.
  • Signs of an allergic reaction such as skin rashes, itching, blisters, peeling skin, swelling of the face, lips, mouth or have problems breathing
  • This is rare.
  • Stop taking your medicines and seek immediate medical attention.
  • Signs of problems with your liver such as yellowing of the skin or eyes, dark urine, pain in the abdomen.
  • This is a rare side effect of flucloxacillin and can occur after you've completed the course.
  • Tell your doctor immediately or ring Healthline 0800 611 116.
  • Signs of problems with your kidneys such as passing urine more often than usual, pain when passing urine, blood in your urine, severe back pain.
  
  • This is rare.
  • Tell your doctor immediately or ring Healthline 0800 611 116.


Read more about medicines and side effects and reporting a reaction you think might be a side effect. 

Cellulitis

Brochures

Medicines and side effects(external link) Healthify He Puna Waiora, NZ, 2024
5 questions to ask about your medications(external link) Health Quality and Safety Commission, NZ, 2019 English(external link), te reo Māori(external link)


References

  1. Probenecid(external link) New Zealand Formulary, NZ
  2. Probenecid(external link) Medsafe datasheet, NZ 
  3. (external link)Pharmacokinetic medicines interactions with probenecid(external link) Christchurch Medicines Information Service, NZ, 2022

Brochures

Medicines and side effects
Healthify He Puna Waiora, NZ, 2024

5 questions to ask about your medications

5 questions to ask about your medications

Health Quality and Safety Commission, NZ, 2019 English, te reo Māori

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Sharon Gardiner, Antimicrobial Stewardship Pharmacist, Health New Zealand | Te Whatu Ora – Waitaha | Canterbury; Angela Lambie, Pharmacist, Auckland

Last reviewed:

Page last updated:

Read more at: https://healthify.nz/medicines-a-z/p/probenecid-with-antibiotics
Healthify is brought to you by Health Navigator Charitable Trust