Pentamidine (Injection)

Pentamidine is used to treat Pneumocystis carinii pneumonia (PCP), which is a very serious type of pneumonia. This type of pneumonia often affects patients with weakened immune systems, such as cancer patients, transplant patients, and patients with acquired immune deficiency syndrome (AIDS). Additionally, your doctor may prescribe pentamidine for other medical issues caused by protozoa. This medicine may also be used for other conditions as decided by your doctor.

Pentamidine can cause some serious side effects. Before you start treatment with pentamidine, you and your doctor should discuss the benefits of this medicine as well as the risks involved.

Pentamidine is to be given only by or under the direct supervision of your doctor.

Some patients may experience sudden, severe low blood pressure after a dose of pentamidine. Therefore, you should lie down while receiving this medicine. Your doctor may also want to check your blood pressure while you are getting a pentamidine injection and several times after the dose until your blood pressure is stable.

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

• Contact your doctor right away if you think you are getting a cold or any other infection.
• Contact your doctor right away if you notice any unusual bleeding or bruising.
• Be cautious when using regular toothbrushes, dental floss, or toothpicks. Your medical doctor, dentist, or nurse may suggest 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. Instead, use an electric shaver. Also, be careful when using fingernail or toenail clippers.

In deciding to use a medicine, you and your doctor should consider the risks of the medicine compared to the benefits it may provide. Here are important factors to think about for this medicine:

Allergies

Inform your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also, let your healthcare professional know about any other allergies you may have, such as to foods, dyes, preservatives, or animals. For non-prescription products, carefully read the label or package ingredients.

Pediatric

Although pentamidine has not been commonly used in children, this medicine is not expected to cause different side effects or problems in children compared to adults.

Geriatric

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

Breast Feeding

There are no adequate studies in women to determine the risk to infants when using this medication during breastfeeding. Consider the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Some medicines should not be used together at all, while in other cases, two different medicines may be used together even if an interaction might occur. If you are taking this medicine, it is especially important for your healthcare professional to know if you are taking any of the medicines listed below. The following interactions are based on 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 necessary in some cases. If both medicines are prescribed together, your doctor may adjust the dose or how often you take 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
• Bretylium
• Buprenorphine
• Buserelin
• Ceritinib
• Chloral Hydrate
• Chloroquine
• Chlorpromazine
• Cidofovir
• Citalopram
• Clarithromycin
• Clofazimine
• Clothiapine
• Clozapine
• Crizotinib
• Dabrafenib
• Dasatinib
• Degarelix
• Delamanid
• 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
• Glasdegib
• Gonadorelin
• Goserelin
• Halofantrine
• Haloperidol
• Halothane
• Histrelin
• Hydroquinidine
• Hydroxychloroquine
• Hydroxyzine
• Ibutilide
• Imipramine
• Inotuzumab Ozogamicin
• Isoflurane
• Isradipine
• Ivabradine
• Ivosidenib
• Ketoconazole
• Lefamulin
• Lenvatinib
• Leuprolide
• Levofloxacin
• Lidoflazine
• Lofexidine
• Lorcainide
• Lumefantrine
• Macimorelin
• Mefloquine
• Methadone
• Methotrimeprazine
• Metronidazole
• Mirtazapine
• Mobocertinib
• Moxifloxacin
• Nafarelin
• Nilotinib
• Nortriptyline
• Octreotide
• Olanzapine
• Ondansetron
• Osilodrostat
• Osimertinib
• Oxaliplatin
• Ozanimod
• Pacritinib
• 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
• Ribociclib
• 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
• Vilanterol
• Vinflunine
• Voclosporin
• Zolmitriptan
• Zotepine
• Zuclopenthixol

Using this medicine with any of the following medicines may increase the 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 adjust the dose or how often you take one or both of the medicines.

• Zalcitabine

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or certain types of food due to potential interactions. Using alcohol or tobacco with some medicines may also cause interactions. Talk to your healthcare professional about using your medicine with food, alcohol, or tobacco.

Other Medical Problems

Having other medical issues may affect the use of this medicine. Be sure to inform 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 worsen these conditions

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

Pentamidine can cause some serious side effects, such as heart issues, low blood pressure, low or high blood sugar, and other blood-related problems. You should talk with your doctor about the benefits of this medicine and the risks involved in taking it.

While a medicine can have important effects, it may also lead to unwanted effects. Not all of these side effects may happen, but if they do, you may need medical help.

Contact your doctor right away if you experience any of these side effects:

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 the injection site
• skin rash, redness, or itching

Note: Signs of diabetes mellitus or high blood sugar, or signs of low blood sugar may also appear several months after you stop taking this medicine.

Some side effects may occur that usually do not require medical attention. These side effects may go away as your body adjusts to the medicine. Your healthcare professional may also suggest ways to prevent or lessen some of these side effects. Talk to your healthcare professional if any of the following side effects persist or are bothersome, or if you have any questions about them:

More common

• Diarrhea
• loss of appetite
• nausea and vomiting

Stomach issues, like nausea and vomiting, or loss of appetite, are common minor side effects seen in pentamidine treatment. However, if you experience these issues along with sharp pain in the upper abdomen or an unusual decrease in urination, contact your doctor immediately.

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

Other side effects not mentioned may also happen in some patients. If you notice any other effects, talk to your healthcare professional.

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

In the U.S.

• Pentam

Available Dosage Forms:

• Powder for Solution

Therapeutic Class: Antiprotozoal

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.