Pronunciation:

pen-TAM-i-deen

Brand Names:

• Pentam

Dosage Forms:

• Powder for Solution

Classifications:

Therapeutic—

Antiprotozoal

Uses of This Medicine:

Pentamidine is used to treat Pneumocystis carinii pneumonia (PCP), a very serious kind of pneumonia. This kind of pneumonia occurs commonly in patients whose immune system is not working normally, such as cancer patients, transplant patients, and patients with acquired immune deficiency syndrome (AIDS). In addition, your doctor may prescribe pentamidine for some other medical problems caused by protozoa. This medicine may also be used for other conditions as determined by your doctor.

Pentamidine may cause some serious side effects. Before you begin treatment with pentamidine, you and your doctor should talk about the good this medicine will do as well as the risks of using it.

Pentamidine is to be administered only by or under the immediate supervision of your doctor.

Before Using This Medicine:

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies—

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Children—

Although pentamidine has not been widely used in children, this medicine is not expected to cause different side effects or problems in children than it does in adults.

Older adults—

Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of pentamidine in the elderly with use in other age groups.

Breast-feeding—

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Other medicines—

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

• Bepridil
• Cisapride
• Dronedarone
• Grepafloxacin
• Levoketoconazole
• Levomethadyl
• Mesoridazine
• Pimozide
• Piperaquine
• Saquinavir
• Sparfloxacin
• Terfenadine
• Thioridazine
• Ziprasidone

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Acecainide
• Acetophenazine
• Adagrasib
• Ajmaline
• Amiodarone
• Amisulpride
• Amitriptyline
• Amoxapine
• Anagrelide
• Apomorphine
• Aprindine
• Aripiprazole
• Aripiprazole Lauroxil
• Arsenic Trioxide
• Artemether
• Astemizole
• Atazanavir
• Azimilide
• Azithromycin
• Bedaquiline
• Bretylium
• Buprenorphine
• Buserelin
• Ceritinib
• Chloral Hydrate
• Chloroquine
• Chlorpromazine
• Cidofovir
• Citalopram
• Clarithromycin
• Clofazimine
• Clothiapine
• Clozapine
• Crizotinib
• Dabrafenib
• Dasatinib
• Degarelix
• Delamanid
• Desflurane
• Desipramine
• Deslorelin
• Deutetrabenazine
• Dexmedetomidine
• Dibenzepin
• Disopyramide
• Dofetilide
• Dolasetron
• Domperidone
• Donepezil
• Doxepin
• Droperidol
• Efavirenz
• Encainide
• Encorafenib
• Enflurane
• Entrectinib
• Erythromycin
• Escitalopram
• Ethopropazine
• Etrasimod
• Fexinidazole
• Fingolimod
• Flecainide
• Fluconazole
• Fluoxetine
• Fluphenazine
• Formoterol
• Fostemsavir
• Gemifloxacin
• Gepirone
• Givinostat
• Glasdegib
• Gonadorelin
• Goserelin
• Halofantrine
• Haloperidol
• Halothane
• Histrelin
• Hydroquinidine
• Hydroxychloroquine
• Hydroxyzine
• Ibutilide
• Iloperidone
• Imipramine
• Inotuzumab Ozogamicin
• Isoflurane
• Isradipine
• Itraconazole
• Ivabradine
• Ivosidenib
• Ketoconazole
• Lefamulin
• Lenvatinib
• Leuprolide
• Levofloxacin
• Lidoflazine
• Lofexidine
• Lonafarnib
• Lorcainide
• Lumefantrine
• Macimorelin
• Mavorixafor
• Mefloquine
• Methadone
• Methotrimeprazine
• Metronidazole
• Mirtazapine
• Mobocertinib
• Moxifloxacin
• Nafarelin
• Nelfinavir
• Nilotinib
• Nortriptyline
• Octreotide
• Olanzapine
• Ondansetron
• Osilodrostat
• Osimertinib
• Oxaliplatin
• Ozanimod
• Pacritinib
• Paliperidone
• Panobinostat
• Paroxetine
• Pasireotide
• Pazopanib
• Perphenazine
• Phenobarbital
• Pimavanserin
• Pipotiazine
• Pirmenol
• Pitolisant
• Ponesimod
• Posaconazole
• Prajmaline
• Primidone
• Probucol
• Procainamide
• Prochlorperazine
• Promazine
• Promethazine
• Propafenone
• Propiomazine
• Protriptyline
• Quetiapine
• Quinidine
• Quizartinib
• Relugolix
• Revumenib
• Ribociclib
• Rilpivirine
• Risperidone
• Selpercatinib
• Sematilide
• Sertindole
• Sertraline
• Sevoflurane
• Siponimod
• Solifenacin
• Sotalol
• Spiramycin
• Sulfamethoxazole
• Sulpiride
• Sultopride
• Sunitinib
• Tacrolimus
• Tedisamil
• Telithromycin
• Thiethylperazine
• Trazodone
• Triclabendazole
• Trifluoperazine
• Triflupromazine
• Trimeprazine
• Trimethoprim
• Trimipramine
• Triptorelin
• Vandetanib
• Vardenafil
• Vemurafenib
• Venlafaxine
• Vilanterol
• Vinflunine
• Voclosporin
• Zolmitriptan
• Zotepine
• Zuclopenthixol

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Zalcitabine

Other interactions—

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems—

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Anemia or
• Bleeding disorders (history of) or
• Heart disease or
• Hypotension (low blood pressure) or
• Kidney disease or
• Liver disease—Pentamidine may make these conditions worse

• Diabetes mellitus (sugar diabetes) or
• Hypoglycemia (low blood sugar)—Pentamidine may increase or decrease blood sugar levels and may disturb control of sugar diabetes

Proper Use of This Medicine:

To help clear up your infection completely, pentamidine must be given for the full time of treatment, even if you begin to feel better after a few days. Also, this medicine works best when there is a constant amount in the blood. To help keep the amount constant, pentamidine must be given on a regular schedule.

Make certain your health care professional knows if you are on a low-sodium, low-sugar, or any other special diet. Since most medicines contain more than their active ingredient, some products may have to be avoided.

Dosing—

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For injection dosage form:
  • For Pneumocystis carinii pneumonia (PCP):
    • Adults and children—Dose is based on body weight and must be determined by your doctor. The usual dose is 4 milligrams (mg) per kilogram (kg) (1.8 mg per pound) of body weight given once a day for fourteen to twenty-one days. This dose is injected slowly into a vein over a one- to two-hour period of time.

Precautions While Using This Medicine:

Some patients may develop sudden, severe low blood pressure after a dose of pentamidine. Therefore, you should be lying down while you are receiving this medicine. Also, your doctor may want to check your blood pressure while you are receiving a pentamidine injection and several times after the dose has been given until your blood pressure is stable.

Pentamidine can lower the number of white blood cells in your blood, increasing the chance of your getting certain infections. It can also lower the number of platelets, which are necessary for proper blood clotting. If these problems occur, there are certain precautions you can take to reduce the risk of infection or bleeding:

• Check with your doctor immediately if you think you are getting a cold or any other infection.
• Check with your doctor immediately if you notice any unusual bleeding or bruising.
• Be careful when using regular toothbrushes, dental floss, or toothpicks. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your health care professional before having any dental work done.
• Avoid using a safety razor. Use an electric shaver instead. Also, be careful when using fingernail or toenail cutters.

Side Effects of This Medicine:

Pentamidine may cause some serious side effects, including heart problems, low blood pressure, low or high blood sugar, and other blood problems. You and your doctor should discuss the good this medicine will do as well as the risks of receiving it.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

Decrease in urination

sore throat and fever

unusual bleeding or bruising

Signs of diabetes mellitus or high blood sugar

Drowsiness

flushed, dry skin

fruit-like breath odor

increased thirst

increased urination

loss of appetite

Signs of low blood sugar

Anxiety

chills

cold sweats

cool, pale skin

headache

increased hunger

nausea

nervousness

shakiness

Signs of low blood pressure

Blurred vision

confusion

dizziness

fainting or lightheadedness

unusual tiredness or weakness

Less common

Fast or irregular pulse

fever

nausea and vomiting

pain in upper abdomen

pain, redness, and/or hardness at place of injection

skin rash, redness, or itching

Note: Signs of diabetes mellitus or high blood sugar, or signs of low blood sugar may also occur up to several months after you stop receiving this medicine.

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Diarrhea

loss of appetite

nausea and vomiting

Stomach problems, such as nausea and vomiting, or loss of appetite, are common minor side effects seen in pentamidine treatment. However, if you have these problems, and at the same time have sharp pain in the upper abdomen, or an unusual decrease in the amount of urine, check with your doctor immediately.

Pentamidine may also cause an unpleasant metallic taste. This side effect is to be expected and does not require medical attention.

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.