A medicine for PCP pneumonia and some parasitic infections
Pentamidine
A specialist medicine used to treat PCP pneumonia (especially when co-trimoxazole is unsuitable) and some parasitic infections, with several serious side effects.
What is Pentamidine?
Pentamidine is a specialist medicine used mainly to treat or help prevent a serious lung infection called PCP pneumonia, particularly when the usual medicine, co-trimoxazole, cannot be used. It is also used for some forms of leishmaniasis and sleeping sickness (trypanosomiasis). It is given by injection or breathed in as a mist. It can cause several serious effects, the most important being a sudden, severe drop in blood pressure (especially with the injection or inhalation), as well as changes in blood sugar (low or high), kidney problems, heart-rhythm changes and inflammation of the pancreas. Because of this, it is given under close medical supervision.
Education and reference only. This is a plain-language guide to Pentamidine — 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
Pentamidine is a specialist anti-infective medicine. Its main use is against PCP pneumonia, a serious lung infection that mostly affects people with a weakened immune system; it is used especially when co-trimoxazole, the usual first choice, is not suitable. It is also used for some parasitic infections, including certain types of leishmaniasis and sleeping sickness (trypanosomiasis). It is given as an injection or, for some uses, breathed in as a fine mist (a nebuliser). It is a powerful medicine with several serious possible side effects, so it is always used under close hospital or specialist supervision.
How it works
Pentamidine works against the organisms that cause PCP pneumonia and certain parasitic infections by interfering with the way they make and use the building blocks they need to grow and survive, so the infection can be cleared. When breathed in as a mist, it is used mainly to help prevent PCP in the lungs in some people at risk. When given by injection, it reaches the rest of the body to treat established infection. Because it acts on processes in the body too, it can cause wide-ranging side effects, which is why how and where it is given is so carefully controlled.
Company & origin
Originated / developed by: Specialist manufacturer.
A specialist medicine used in the UK for a type of pneumonia called PCP and for certain parasitic infections, given under close supervision.
Practical use
How to take Pentamidine
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given by a healthcare team, either as an injection or breathed in as a mist, under close supervision.
- Lie down during and after an injection or inhalation as instructed, because blood pressure can drop suddenly and severely.
- Attend all checks for blood pressure, blood sugar, kidney function and heart rhythm during and after treatment.
- Report straight away any dizziness, faintness, unusual thirst, severe tummy pain or a fast or irregular heartbeat.
- Tell your team about all your other medicines, especially any that affect the heart rhythm, kidneys or blood sugar.
Weighing it up
Advantages & disadvantages of Pentamidine
Advantages
- An effective treatment for PCP pneumonia, especially when co-trimoxazole cannot be used.
- Also treats some forms of leishmaniasis and sleeping sickness (trypanosomiasis).
- Can be breathed in as a mist to help prevent PCP in some people at risk.
Disadvantages
- Can cause a sudden, severe drop in blood pressure, especially with injection or inhalation.
- Can cause low or high blood sugar, kidney injury, heart-rhythm changes and inflammation of the pancreas.
- Needs close medical supervision and careful monitoring, often in hospital.
Practical use
Good to know
The key thing with pentamidine is that it is a powerful medicine with several serious possible side effects, so it is given under close supervision, often in hospital. The most important is a sudden, severe drop in blood pressure, which can happen especially with the injection or when it is breathed in, so people are watched closely and kept lying down during and after treatment. It can also cause low or high blood sugar, sometimes appearing days or weeks later, so blood sugar is checked. Other important risks include kidney injury, changes in the heart's rhythm (the QT interval), and inflammation of the pancreas (pancreatitis). When breathed in as a mist it can cause coughing and wheeze. Because of all this, treatment is closely monitored with blood pressure, blood sugar, kidney and heart checks, and any new symptoms should be reported at once.
Who should not take it / use with caution
- People who have had a serious allergic reaction to pentamidine should not be given it.
- It is used with great care in people with low blood pressure, diabetes or blood-sugar problems, kidney problems, heart-rhythm problems or pancreatitis.
- It is used with care, and under specialist judgement, in pregnancy.
- It is given only under close medical or hospital supervision.
Monitoring
- Close blood-pressure checks during and after treatment, with the person lying down.
- Regular blood-sugar checks, including after treatment, as changes can be delayed.
- Kidney function blood tests and heart-rhythm checks during treatment.
- Watching for signs of pancreatitis, such as severe tummy pain.
Side effects
- A sudden, severe drop in blood pressure, causing dizziness or fainting, especially with injection or inhalation.
- Low or high blood sugar, which can appear during treatment or later.
- Kidney problems, shown by blood tests, and changes in the heart's rhythm (the QT interval).
- Inflammation of the pancreas (pancreatitis), causing severe tummy pain, which needs urgent attention.
- Coughing, wheeze or shortness of breath when breathed in as a mist.
Key interactions
- Medicines that also affect the heart's QT interval can add to the risk of heart-rhythm problems, so these are reviewed.
- Medicines that can affect the kidneys may add to the risk of kidney injury, so tell your team about them.
- Medicines that affect blood sugar may need closer monitoring when used alongside pentamidine.
Available as: A solution for injection and a form breathed in as a fine mist (a nebuliser).
Answers
Pentamidine: frequently asked questions
What is pentamidine used for?
It is mainly used to treat or help prevent PCP pneumonia, especially when co-trimoxazole cannot be used, and also treats some forms of leishmaniasis and sleeping sickness.
Why must I lie down when it is given?
Pentamidine can cause a sudden, severe drop in blood pressure, especially with the injection or when breathed in, so lying down and being closely watched helps keep you safe.
Why does my blood sugar need checking?
Pentamidine can cause low or high blood sugar, sometimes during treatment and sometimes days or weeks later, so blood sugar is monitored carefully.
What serious side effects should I watch for?
Tell your team straight away about dizziness or fainting, unusual thirst, severe tummy pain (a sign of pancreatitis) or a fast or irregular heartbeat.
Why is it given in hospital or under close supervision?
It can cause several serious effects, including a severe blood-pressure drop, kidney, heart-rhythm and blood-sugar problems, so close monitoring is needed to use it safely.
Authoritative sources
- BNF
- NICE CKS
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