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Pentamidine (Oral Inhalation)

Medically reviewed by Last updated on Sep 23, 2020.


(pen TAM i deen)

Index Terms

  • Pentamidine Diisetionate
  • Pentamidine Isethionate
  • Pentamidine Isetionate

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Solution Reconstituted, Inhalation, as isethionate:

Nebupent: 300 mg (1 ea)

Generic: 300 mg (1 ea)

Brand Names: U.S.

  • Nebupent

Pharmacologic Category

  • Antifungal Agent
  • Antiprotozoal


Interferes with microbial RNA/DNA, phospholipids and protein synthesis, through inhibition of oxidative phosphorylation and/or interference with incorporation of nucleotides and nucleic acids into RNA and DNA


Inhalation: Limited systemic absorption with chronic therapy, potential accumulation and systemic effects unknown


Binds to tissues and plasma protein; high concentrations are found in the liver, kidney, adrenals, spleen, lungs, and pancreas; poor penetration into CNS; following oral inhalation, high concentrations are found in bronchoalveolar fluid

Half-Life Elimination

IV: 5 to 8 hours; IM: 7 to 11 hours; may be prolonged with severe renal impairment

Use: Labeled Indications

Prevention of Pneumocystis jirovecii pneumonia (PCP) in high-risk, patients with HIV either with a history of PCP or with a CD4+ count ≤200/mm3.


Hypersensitivity to pentamidine isethionate or any component of the formulation

Dosing: Adult

Pneumocystis jirovecii pneumonia, prevention:Primary or secondary prophylaxis (alternative agent): Inhalation: 300 mg once every 4 weeks via Respirgard II nebulizer. Continue prophylaxis following initiation of antiretroviral therapy (ART) until CD4 count >200 cells/mm3 for >3 months; some experts discontinue prophylaxis in patients with a CD4 count between 100 to 200 cells/mm3 who are receiving ART and have had an undetectable viral load for ≥3 to 6 months (HHS [OI adult 2020]).

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Pneumocystis jirovecii pneumonia; primary or secondary prophylaxis (alternative agent): Limited data available:

Children <5 years:

Hematopoietic stem cell transplantation recipients: Inhalation: 9 mg/kg (maximum dose: 300 mg/dose) once monthly (every 4 weeks) via Respirgard II nebulizer (Tomblyn 2009).

Leukemia patients (Weinthal 1994): Inhalation:

Children <4 years: 150 mg/dose once monthly (every 4 weeks) via Respirgard II nebulizer.

Children 4 to 5 years: 300 mg/dose once monthly (every 4 weeks) via Respirgard II nebulizer.

Children ≥5 years and Adolescents: Inhalation: 300 mg once monthly (every 4 weeks) via Respirgard II nebulizer (HHS [OI adult 2020]; HHS [OI pediatric 2019]; Red Book [AAP 2018]; Quinn 2017; Tomblyn 2009).


Reconstitute with 6 mL SWFI. Do not use sodium chloride for initial reconstitution (sodium chloride will cause precipitation). Do not mix with other nebulizer solutions.


Inhalation: Deliver via Respirgard II nebulizer until nebulizer is emptied (30-45 minutes). Administer at a flow rate of 5 to 7 L/minute from a 40 to 50 pound-per-square inch (PSI) oxygen or air source. A 40-50 PSI air compressor can be used alternatively, with a set flow rate at 5 to 7 L/minute or a set pressure of 22 to 25 PSI. Air compressors <20 PSI should not be used. Use appropriate precautions to minimize exposure to healthcare personnel; refer to individual institutional policy.


Store intact vials at 20°C to 25°C (68°F to 77°F); protect from light.

The manufacturer recommends the use of freshly prepared solutions for inhalation; however, may be stored for up to 48 hours in the vial at room temperature if protected from light.

Drug Interactions

There are no known significant interactions.

Adverse Reactions


Central nervous system: Fatigue (66%), dizziness (45%)

Gastrointestinal: Decreased appetite (50%)

Infection: Infection (15%)

Respiratory: Cough (1% to 63%), dyspnea (48%), wheezing (32%), bronchospasm (≤15%)

Miscellaneous: Fever (51%)

1% to 5%:

Cardiovascular: Chest pain

Central nervous system: Headache

Dermatologic: Night sweats

Gastrointestinal: Diarrhea, dysgeusia, nausea, oral candidiasis

Hematologic & oncologic: Anemia

Infection: Herpes virus infection, herpes zoster, influenza

Respiratory: Pharyngitis (≤5%), bronchitis, sinusitis, upper respiratory tract infection

Miscellaneous: Night sweats

<1%, postmarketing, and/or case reports: Abscess (oral), abdominal cramps, andominal pain, acute pancreatitis, acute rhinitis, ageusia, amnesia, anaphylaxis, anxiety, arthralgia, asthma, bacterial pneumonia, blepharitis, blurred vision, body odor, bronchitis, cerebrovascular accident, chest congestion, chest tightness, colitis, confusion, conjunctivitis, constipation, contact lens intolerance, cyanosis, cytomegalovirus disease (including colitis and retinitis), cytopenia, depression, dermatitis, desquamation, diabetes mellitus, disuption of body temperature regulation, drowsiness, dry hair, dyspepsia, dyspnea, emotional lability, encephalitis (viral), eosinophilia, eosinophilic pneumonitis, erythema, esophageal candidiasis, esophagitis, eye pain, facial edema, flank pain, gag reflex, gastritis, gastric ulcer, gingivitis, gout, hallucination, hematochezia, hemianopia, hemoptysis, hepatic insufficiency, hepatitis, hepatomegaly, herpes virus infection (pharyngeal), hiatal hernia, histoplasmosis, hyperglycemia, hyperkalemia, hypersensitivity reaction, hypertension, hyperventilation, hypocalcemia, hypoesthesia, hypoglycemia, hypotension, hypothermia, hypoxia, increased blood urea nitrogen, increased bronchial secretions, increased serum creatinine, infection (mycoplasma), insomnia, interstitial pneumonitis, Kaposi's sarcoma, laryngitis, laryngospasm, lethargy, lower extremity edema, melena, meningitis (cryptococcal infection), myalgia, nasal congestion, nephritis, nervousness, neuralgia, neuropathy, neutropenia, oral herpes, oral mucosa ulcer, otitis, palpitations, pancreatitis, pancytopenia, paranoia, paresthesia, peripheral neuropathy, pleurisy, pneumothorax, pruritus, pulmonary disease, rales, renal failure, renal insufficiency, renal pain, rhinitis, seizure, sepsis (central venous line-related), serious infection (extrapulmonary pneumocystosis), SIADH, sialorrhea, skin rash, splenomegaly, Stevens-Johnson syndrome, ST segment changes on ECG, syncope, tachycardia, tachypnea, thrombocytopenia, tonsillitis, torsades de pointes, tremor, tuberculosis, unsteady gait, urinary incontinence, urticaria, vasodilation, vasculitis, ventricular tachycardia, vertigo, vomiting, xeroderma, xerostomia


Disease-related concerns:

• Asthma: Use inhalation formulation with caution in patients with asthma. May induce bronchospasm or cough, especially in patients with a smoking or asthma history (an inhaled bronchodilator prior to pentamidine may ameliorate symptoms).

• Pancreatitis: Use with caution in patients with a history of pancreatic disease or elevated amylase/lipase levels; acute pancreatitis (with fatality) has been reported. Discontinue inhalational pentamidine if signs/symptoms of acute pancreatitis occur.

• PCP: Acute PCP may develop despite aerosolized pentamidine prophylaxis. Although rare, extrapulmonary PCP disease may occur and has been associated with aerosolized pentamidine. Use appropriate precautions to minimize exposure to healthcare personnel; refer to individual institutional policy.

Other warnings/precautions:

• Adverse effects: Injection: According to the manufacturer, extent and consequence of pentamidine accumulation following chronic inhalation therapy are not known. Patients receiving pentamidine inhalation should be closely monitored for the development of serious adverse reactions that have occurred in patients receiving parenteral pentamidine, including hypotension, hypoglycemia, hyperglycemia, hypocalcemia, anemia, thrombocytopenia, leukopenia, hepatic or renal dysfunction, ventricular tachycardia (eg, torsade de pointes), pancreatitis, Stevens-Johnson syndrome, hyperkalemia and abnormal ST segment of ECG.

Monitoring Parameters

Liver function tests, renal function tests, blood glucose, serum potassium and calcium, CBC and platelets

Pregnancy Risk Factor


Pregnancy Considerations

It is not known if clinically significant concentrations reach the fetus when administered via the aerosolized route. Information related to fetal outcomes following maternal use of pentamidine is limited. If administered via the aerosolized route, maternal serum concentrations are lower, minimizing the exposure to the fetus (Gates 1993; Nanda 1992; Sperling 1992). Concern regarding occupational exposure and theoretical risk to pregnant health care workers has been discussed in the literature. Pregnant health care workers should avoid aerosolized exposure if possible (Conover 1988; Ito 1994; Smaldone 1991).

Aerosolized pentamidine may be used as an alternative agent for the prophylaxis of Pneumocystis pneumonia (PCP) in pregnant females with HIV infection who either cannot tolerate the preferred therapy or who wish to avoid it during the first trimester of pregnancy (HHS [OI adult 2020]).

Patient Education

What is this drug used for?

• It is used to prevent Pneumocystis jirovecii pneumonia.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Cough

• Lack of appetite

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Infection

• Liver problems like dark urine, fatigue, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or yellow skin

• Kidney problems like unable to pass urine, blood in the urine, change in amount of urine passed, or weight gain

• Low blood sugar like dizziness, headache, fatigue, feeling weak, shaking, fast heartbeat, confusion, increased hunger, or sweating

• High blood sugar like confusion, fatigue, increased thirst, increased hunger, passing a lot of urine, flushing, fast breathing, or breath that smells like fruit

• Stevens-Johnson syndrome/toxic epidermal necrolysis like red, swollen, blistered, or peeling skin (with or without fever); red or irritated eyes; or sores in mouth, throat, nose, or eyes

• Low calcium like muscle cramps or spasms, numbness and tingling, or seizures

• Pancreatitis like severe abdominal pain, severe back pain, severe nausea, or vomiting

• High potassium like abnormal heartbeat, confusion, dizziness, passing out, weakness, shortness of breath, or numbness or tingling feeling

• Abnormal heartbeat

• Severe dizziness

• Passing out

• Bruising

• Bleeding

• Severe loss of strength and energy

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.