An antiviral for CMV
Cidofovir
A hospital drip for CMV eye infection, given with a protective medicine and fluids because of significant kidney toxicity.
What is Cidofovir?
Cidofovir is a specialist antiviral given as a drip into a vein in hospital, mainly to treat cytomegalovirus (CMV) infection of the eye in people with weakened immunity. Its main concern is significant toxicity to the kidneys, so it is always given together with a protective medicine called probenecid and with plenty of fluids, and the kidneys are checked closely. Because of these risks it is hospital-only and given less often than some other antivirals. The brand name is Vistide.
Education and reference only. This is a plain-language guide to Cidofovir — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Cidofovir is an antiviral medicine used to treat cytomegalovirus (CMV) infection, particularly CMV affecting the eye (retinitis) in people whose immune system is weakened, such as those with advanced HIV. It is given as a drip into a vein in hospital. Because it can be hard on the kidneys, it is always given alongside a tablet called probenecid and with fluids into a vein to help protect them. It is a specialist, hospital-only medicine, with the brand name Vistide.
How it works
Cidofovir is taken up into virus-infected cells and converted into an active form that blocks the enzyme the virus uses to copy its genetic material, stopping the virus from multiplying. It stays active in cells for a long time, which is why it can be given less frequently than some other antivirals. However, it concentrates in the kidneys, where it can cause damage, so the protective medicine probenecid and generous fluids are used to reduce how much builds up in the kidney tissue.
Company & origin
Originated / developed by: Generic (specialist).
A specialist antiviral given by drip in UK hospitals for cytomegalovirus (CMV) eye infection, with measures to protect the kidneys.
Practical use
How to take Cidofovir
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given as a drip into a vein in hospital, together with fluids to help protect your kidneys.
- You will also take probenecid tablets around each dose; take them as directed, sometimes with food to reduce nausea.
- Your kidney function and a urine check are done before each treatment, and treatment is delayed if your kidneys are not well enough.
- Use reliable contraception during treatment and for the period afterwards that your team advises, as it can harm an unborn baby.
- Report any change in your urine, swelling, or new eye symptoms straight away.
Weighing it up
Advantages & disadvantages of Cidofovir
Advantages
- An effective option for CMV eye infection when other treatments are unsuitable.
- Stays active in cells for a long time, so it can be given less frequently than some antivirals.
- Given with a protective medicine and fluids, and closely monitored, to reduce kidney risk.
Disadvantages
- Has significant toxicity to the kidneys, needing a protective medicine, fluids and close monitoring.
- Can only be given as a hospital drip, with treatment delayed if the kidneys are not well enough.
- Can affect the eyes and blood counts, and can harm an unborn baby.
Practical use
Good to know
The key concern with cidofovir is significant toxicity to the kidneys, which can show up as protein in the urine or a rise in kidney blood tests, so kidney function and urine are checked before each treatment and the treatment is not given if the kidneys are not well enough. To reduce the risk, it is always given with the tablet probenecid and with fluids into a vein around each dose. Probenecid itself can cause nausea, and some people take it with food or anti-sickness medicine. Cidofovir can also affect the eyes (such as low eye pressure or inflammation) and the blood counts, so these are monitored. It can harm an unborn baby and may affect fertility, so reliable contraception is advised during treatment and for a period afterwards.
Who should not take it / use with caution
- People with significant kidney problems or protein in the urine should not usually receive it.
- It is avoided in those who cannot take probenecid or have a severe sulfa-type allergy related to it.
- It is avoided in pregnancy unless essential, because it can harm an unborn baby.
Monitoring
- Kidney function and urine checks before each dose, with treatment delayed if needed.
- Regular blood counts and eye reviews during treatment.
- Watching the response of the infection and managing nausea from probenecid.
Side effects
- Kidney problems, including protein in the urine and rises in kidney blood tests, are an important risk.
- Nausea and vomiting, often related to the probenecid given with it, and low blood counts.
- Eye effects such as inflammation or low eye pressure, fever and headache.
Key interactions
- Combining it with other medicines that can harm the kidneys must be avoided or carefully managed.
- Probenecid, given with it, affects how the body handles some other medicines, so the team reviews your list.
- Other medicines that affect the blood counts can add to that risk.
Available as: A drip into a vein, given in hospital, alongside probenecid tablets.
Answers
Cidofovir: frequently asked questions
What is cidofovir used for?
It is a specialist antiviral used mainly to treat cytomegalovirus (CMV) infection of the eye in people whose immune system is weakened.
Why do I take probenecid and fluids with it?
Cidofovir can be toxic to the kidneys, and probenecid tablets plus fluids into a vein help protect the kidneys around each dose.
Why is treatment sometimes delayed?
Your kidney function and urine are checked before each dose, and treatment is delayed if your kidneys are not well enough to receive it safely.
Can it affect my eyes?
Yes, it can cause eye inflammation or low eye pressure, so your eyes are monitored; report any new eye symptoms straight away.
Is it safe in pregnancy?
It can harm an unborn baby, so it is avoided in pregnancy unless essential, and reliable contraception is advised during treatment and for a period afterwards.
The wider class
About Antiviral (CMV)
Cidofovir belongs to the antiviral (cmv) class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
Browse by body system
Authoritative sources
- BNF
- NICE CKS
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