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Pentamidine is used to treat a type of pneumonia called Pneumocystis pneumonia (PCP). Loss of appetite and nausea are common side effects. Tell your health care provider right away if you have any pain or discomfort where you get this medicine. If pentamidine is given to you by an infusion into a vein, your infusion may need to be slowed or stopped. Get emergency help if you have trouble breathing or chest pain.

Uses

What is pentamidine used for?

Pentamidine is used to treat a type of pneumonia called Pneumocystis pneumonia (PCP)

Pentamidine may also be used for other conditions as determined by your health care provider.

Pentamidine is also available in a form that is inhaled. See Pentamidine inhaled (NebuPent) for more information.

How does pentamidine work (mechanism of action)?

Pentamidine kills the invasive fungus that causes PCP by stopping it from making important cellular parts like DNA or proteins.

How is pentamidine supplied (dosage forms)?

Brands and other names

  • Pentam

Dosage forms and strengths

Pentamidine is available in an injectable form that is given by a health care provider.

How should I store pentamidine?

Pentamidine is usually given by a health care provider in a hospital or clinic. You will not store it at home.

Side Effects

What are the most common side effects of pentamidine?

The most common side effects of pentamidine are listed below. Tell your health care provider if you have any of these side effects that bother you.

  • Low blood pressure (see below)
  • Loss of appetite
  • Nausea
  • Low blood cell counts
  • Abnormal liver test results
  • Low blood sugar (see below)
  • Pain or discomfort near the injection site
  • Kidney damage (see below)

There may be other side effects of pentamidine that are not listed here. Contact your health care provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088 (800-332-1088). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of pentamidine?

While less common, the most serious side effects of pentamidine are described below, along with what to do if they happen.

Severe Allergic Reactions. Pentamidine may cause allergic reactions, which can be serious. Get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Low Blood Pressure (Hypotension). Pentamidine may cause low blood pressure. If you feel faint or dizzy, lie down. Tell your health care provider right away if you have any of the following symptoms of low blood pressure.

  • Dizziness, feeling lightheaded, or fainting
  • Confusion
  • Feeling weak or tired

Low Blood Sugar (Hypoglycemia). Pentamidine can cause low blood sugar, which can be serious and may lead to death. You may need to check your blood sugar more often if you have changes to your diet, exercise regimen, or medicines for diabetes. Call your health care provider right away if you have any of the following symptoms of hypoglycemia.

  • Headache
  • Crankiness or anxiety
  • Hunger
  • Dizziness or confusion
  • Blurry vision
  • Slurred speech
  • Sweating
  • Feeling jittery or shakiness
  • Fast heartbeat
  • Seizures

High Blood Sugar. Pentamidine may increase your blood sugar levels. This may occur with or without a preceding episode of low blood sugar. High blood sugar may also occur several months after the treatment ends. Talk to your health care provider about how to maintain healthy blood sugar levels. Keep all appointments with your health care provider to check your blood tests. Call your health care provider if you have the following symptoms of high blood sugar.

  • Thirstier than usual
  • Peeing more than usual
  • Increase in hunger
  • Tiredness
  • Feeling sick to your stomach
  • Confusion
  • Fruity-smelling breath

Inflammation of the Pancreas (Pancreatitis). Pentamidine may cause inflammation of the pancreas, which is called pancreatitis. Call your health care provider right away if you have symptoms of pancreatitis, including vomiting or severe pain in the upper part of your belly that travels to your back.

Abnormal Heart Rhythm (Arrhythmia). Pentamidine may cause an abnormal heart rhythm (arrhythmia). Call your health care provider or get medical attention right away if you have chest pain, a fast or irregular heartbeat, or if you feel your heartbeat more than usual.

Kidney Damage. Kidney damage can happen when using pentamidine. Call your health care provider right away if you have any of the following symptoms of kidney damage.

  • Reduced need to pee
  • Swelling in your feet, ankles, or legs
  • Weakness or unusual tiredness
  • Difficulty catching your breath or chest pain/pressure
  • Confusion
  • Nausea
  • Seizures

Tissue Damage. Pentamidine is given as an infusion into a vein. If the medicine does not go into your vein, it could damage nearby tissue. Tell your health care provider right away if you have pain, swelling, warmth, or skin color changes where the medicine is being or was given.

Warnings & Precautions

Who should not use pentamidine?

Allergies to Ingredients. People who are allergic to any of the following should not use pentamidine.

  • Pentam
  • Pentamidine
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific pentamidine products they stock.

What should I know about pentamidine before using it?

Pentamidine is usually given by a health care provider in a hospital or clinic. 

Pentamidine can cause dizziness or loss of coordination due to low blood pressure or low blood sugar. Do not drive or do other activities that require alertness or coordination until you know how pentamidine affects you.

Your health care provider may perform certain tests, such as liver or kidney function tests, blood cell counts, and blood sugar tests. These tests may be done before, during, and/or after your treatment with pentamidine to look for any problems that may happen from using this medicine. Keep all appointments.

What should I tell my health care provider before using pentamidine?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if pentamidine is right for you.

In particular, make sure that you discuss any of the following.

Other Medicines and Supplements. Pentamidine may interact with other medicines and supplements. Before using pentamidine, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Current and Past Health Conditions. Tell your health care provider if you have any of the following.

  • Blood pressure problems (high or low)
  • Heart rate or rhythm problems
  • Blood sugar problems (high or low)
  • Low calcium levels
  • Pancreas problems
  • Low blood cell counts, including anemia, thrombocytopenia, or leukopenia
  • Kidney problems
  • Liver problems
  • History of severe skin reactions to medicines, including Stevens-Johnson syndrome

Pregnancy. It is not known if or how pentamidine could affect pregnancy or harm a fetus. Tell your health care provider if you are pregnant or plan to become pregnant.

Breastfeeding. It is not known if pentamidine passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed. Your health care provider will let you know if you should stop breastfeeding or stop pentamidine.

Interactions

Does pentamidine interact with foods or drinks?

There are no known interactions between pentamidine and foods or drinks.

It is unknown if drinking alcohol will affect pentamidine, but heavy drinking can slow your immune response and make it harder for your body to fight infection.

Does pentamidine interact with other medicines (drug interactions)?

Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before using pentamidine. 

  • Cisplatin, which is a medicine used to treat certain cancers 
  • Amphotericin B (Abelcet, AmBisome), which is a medicine used to treat fungal infections
  • An aminoglycoside antibiotic, such as amikacin or gentamicin, which is a medicine given by injection to treat infections
  • Vancomycin (Firvanq, Vancocin), which is an antibiotic used to treat certain infections
  • Foscarnet (Foscavir), which is a medicine used to treat certain viral infections

This may not be a complete list of medicines that can interact with pentamidine. Always check with your health care provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much pentamidine?

If you or someone else has used too much pentamidine, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of pentamidine?

Pentamidine is usually given by a health care provider in a hospital. Your health care provider will make sure you are receiving pentamidine as scheduled. If you miss an appointment to get your pentamidine dose, call to make another appointment as soon as possible. 

It is important to complete your prescribed course of pentamidine, even if your symptoms get better or go away. This will reduce the risk that future infections are resistant to pentamidine or other similar medicines.