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Pentamidine (Systemic)

Medically reviewed by Drugs.com. Last updated on Apr 8, 2020.

Pronunciation

(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, Injection, as isethionate [preservative free]:

Pentam: 300 mg (1 ea)

Generic: 300 mg (1 ea)

Brand Names: U.S.

  • Pentam

Pharmacologic Category

  • Antifungal Agent
  • Antiprotozoal

Pharmacology

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

Absorption

IM: Well absorbed

Distribution

Binds to tissues and plasma protein; high concentrations are found in the liver, kidney, adrenals, spleen, lungs, and pancreas; poor penetration into CNS; Vdss: IV: 286 to 1356 L; IM: 1658 to 3790 L

Excretion

Urine (IV: ≤12% as unchanged drug)

Half-Life Elimination

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

Special Populations: Renal Function Impairment

Pentamidine may accumulate in renal failure.

Use: Labeled Indications

Treatment of pneumonia caused by Pneumocystis jirovecii pneumonia (PCP)

Off Label Uses

West African trypanosomiasis (Trypanosoma brucei gambiense infection; sleeping sickness), hemolymphatic stage

The Centers for Disease Control and Prevention (CDC) suggest pentamidine may be beneficial in treating the hemolymphatic stage of T. b. gambiense infection in individuals with trypanosomiasis [CDC 2019].

Contraindications

Hypersensitivity to pentamidine isethionate or any component of the formulation

Dosing: Adult

Pneumocystis jirovecii pneumonia (PCP), treatment (alternative agent): IV: 4 mg/kg/dose once daily (manufacturer's labeling) for 21 days; may reduce to 3 mg/kg/dose once daily if toxicity occurs (HHS [OI adult 2020]).

West African trypanosomiasis (Trypanosoma brucei gambiense infection; sleeping sickness), hemolymphatic stage (off-label use): IM, IV: 4 mg/kg once daily for 7 to 10 days (CDC 2019).

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Pneumocystis jirovecii (PCP), prophylaxis (primary and secondary) in oncology patients (including HSCT recipients): Limited data available: Note: For patients intolerant to sulfamethoxazole and trimethoprim. Children ≥2 years and Adolescents: IV: 4 mg/kg/dose once a month (Kim 2008; Prasad 2007); in HSCT recipient doses have been administered every 2 to 4 weeks (Tomblyn [CDC/IDSA 2009])

PCP, treatment (moderate-severe disease): Note: For patients who cannot tolerate or who fail to respond to 5 to 7 days of sulfamethoxazole and trimethoprim.

Manufacturer's labeling: Infants ≥5 months, Children, and Adolescents: IM, IV: 4 mg/kg/dose once daily for 14 to 21 days

HIV-exposed/-positive:

Infants and Children: IV: 4 mg/kg/dose once daily; if clinical improvement after 7 to 10 days of therapy, may change to an oral regimen to complete a 21-day course (DHHS [pediatric] 2013)

Adolescents: IV: 4 mg/kg/dose once daily for 21 days; some experts recommend a dose reduction to 3 mg/kg/dose for toxicity (DHHS [adult] 2015)

Non-HIV-exposed/-positive: Infants, Children, and Adolescents: IV: 3 to 4 mg/kg/dose once daily for 21 days (Bradley 2015)

Trypanosomiasis; treatment (non-CNS disease): Infants, Children, and Adolescents: IM, IV: 4 mg/kg/dose once daily for 7 to 10 days (Bradley 2015; Red Book [AAP 2015])

Reconstitution

Do not use sodium chloride for initial reconstitution (sodium chloride will cause precipitation).

IM: Reconstitute with 3 mL SWFI; IV: Reconstitute with 3 to 5 mL SWFI or D5W; the manufacturer recommends further dilution in 50 to 250 mL D5W; however, stability with further dilution in NS has also been documented.

Administration

Do not use NS to reconstitute.

IM: Administer deep IM

IV: Infuse slowly over 60 to 120 minutes.

Irritant with vesicant-like properties; ensure proper needle or catheter placement prior to and during infusion. Avoid extravasation.

Extravasation management: If extravasation occurs, stop infusion immediately and disconnect (leave cannula/needle in place); gently aspirate extravasated solution (do NOT flush the line); remove needle/cannula; elevate extremity. Apply dry warm compresses (Reynolds 2014).

Storage

Store intact vials at 20°C to 25°C (68°F to 77°F); protect from light. Do not use sodium chloride for initial reconstitution (sodium chloride will cause precipitation).

Reconstituted solution is stable for 48 hours in the vial at room temperature and protected from light. Solutions for injection (1 to 2.5 mg/mL) in D5W are stable for at least 24 hours at room temperature. Store at room temperature to avoid crystallization.

Drug Interactions

Amisulpride (Oral): May enhance the QTc-prolonging effect of Pentamidine (Systemic). Monitor therapy

Androgens: May enhance the hypoglycemic effect of Agents with Blood Glucose Lowering Effects. Exceptions: Danazol. Monitor therapy

Antidiabetic Agents: May enhance the hypoglycemic effect of Hypoglycemia-Associated Agents. Monitor therapy

Antidiabetic Agents: Hyperglycemia-Associated Agents may diminish the therapeutic effect of Antidiabetic Agents. Monitor therapy

BCG (Intravesical): Antibiotics may diminish the therapeutic effect of BCG (Intravesical). Avoid combination

BCG Vaccine (Immunization): Antibiotics may diminish the therapeutic effect of BCG Vaccine (Immunization). Monitor therapy

Cholera Vaccine: Antibiotics may diminish the therapeutic effect of Cholera Vaccine. Management: Avoid cholera vaccine in patients receiving systemic antibiotics, and within 14 days following the use of oral or parenteral antibiotics. Avoid combination

Domperidone: May enhance the QTc-prolonging effect of Pentamidine (Systemic). Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Consider therapy modification

Fexinidazole [INT]: Pentamidine (Systemic) may enhance the QTc-prolonging effect of Fexinidazole [INT]. Avoid combination

Foscarnet: Pentamidine (Systemic) may enhance the adverse/toxic effect of Foscarnet. The specific toxicities may include hypocalcemia, renal failure, and QT-prolongation. Management: Consider alternatives to this combination when possible. If this combination must be used, monitor patients more closely for hypocalcemia, renal dysfunction, and QT interval prolongation. Consider therapy modification

Haloperidol: May enhance the QTc-prolonging effect of Pentamidine (Systemic). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

Herbs (Hypoglycemic Properties): May enhance the hypoglycemic effect of Hypoglycemia-Associated Agents. Monitor therapy

Hypoglycemia-Associated Agents: May enhance the hypoglycemic effect of other Hypoglycemia-Associated Agents. Monitor therapy

Lactobacillus and Estriol: Antibiotics may diminish the therapeutic effect of Lactobacillus and Estriol. Monitor therapy

Maitake: May enhance the hypoglycemic effect of Agents with Blood Glucose Lowering Effects. Monitor therapy

Mequitazine: Pentamidine (Systemic) may enhance the arrhythmogenic effect of Mequitazine. Management: Consider alternatives to pentamidine or mequitazine when possible. While this combination is not specifically contraindicated, mequitazine labeling describes this combination as discouraged. Consider therapy modification

Monoamine Oxidase Inhibitors: May enhance the hypoglycemic effect of Agents with Blood Glucose Lowering Effects. Monitor therapy

Ondansetron: Pentamidine (Systemic) may enhance the QTc-prolonging effect of Ondansetron. Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

Pegvisomant: May enhance the hypoglycemic effect of Agents with Blood Glucose Lowering Effects. Monitor therapy

Pimozide: May enhance the QTc-prolonging effect of Pentamidine (Systemic). Avoid combination

Prothionamide: May enhance the hypoglycemic effect of Agents with Blood Glucose Lowering Effects. Monitor therapy

QT-prolonging Agents (Highest Risk): May enhance the QTc-prolonging effect of Pentamidine (Systemic). Management: Consider alternatives to this combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk. Consider therapy modification

QT-prolonging Antidepressants (Moderate Risk): Pentamidine (Systemic) may enhance the QTc-prolonging effect of QT-prolonging Antidepressants (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

QT-prolonging Antipsychotics (Moderate Risk): Pentamidine (Systemic) may enhance the QTc-prolonging effect of QT-prolonging Antipsychotics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Exceptions: Pimozide. Monitor therapy

QT-prolonging Class IC Antiarrhythmics (Moderate Risk): May enhance the QTc-prolonging effect of Pentamidine (Systemic). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

QT-prolonging Kinase Inhibitors (Moderate Risk): Pentamidine (Systemic) may enhance the QTc-prolonging effect of QT-prolonging Kinase Inhibitors (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

QT-prolonging Miscellaneous Agents (Moderate Risk): May enhance the QTc-prolonging effect of Pentamidine (Systemic). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Exceptions: Domperidone. Monitor therapy

QT-prolonging Moderate CYP3A4 Inhibitors (Moderate Risk): Pentamidine (Systemic) may enhance the QTc-prolonging effect of QT-prolonging Moderate CYP3A4 Inhibitors (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

QT-prolonging Quinolone Antibiotics (Moderate Risk): Pentamidine (Systemic) may enhance the QTc-prolonging effect of QT-prolonging Quinolone Antibiotics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk): Pentamidine (Systemic) may enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

Quinolones: May enhance the hypoglycemic effect of Agents with Blood Glucose Lowering Effects. Quinolones may diminish the therapeutic effect of Agents with Blood Glucose Lowering Effects. Specifically, if an agent is being used to treat diabetes, loss of blood sugar control may occur with quinolone use. Monitor therapy

Salicylates: May enhance the hypoglycemic effect of Agents with Blood Glucose Lowering Effects. Monitor therapy

Saquinavir: Pentamidine (Systemic) may enhance the QTc-prolonging effect of Saquinavir. Avoid combination

Selective Serotonin Reuptake Inhibitors: May enhance the hypoglycemic effect of Agents with Blood Glucose Lowering Effects. Monitor therapy

Sodium Picosulfate: Antibiotics may diminish the therapeutic effect of Sodium Picosulfate. Management: Consider using an alternative product for bowel cleansing prior to a colonoscopy in patients who have recently used or are concurrently using an antibiotic. Consider therapy modification

Typhoid Vaccine: Antibiotics may diminish the therapeutic effect of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Vaccination with live attenuated typhoid vaccine (Ty21a) should be avoided in patients being treated with systemic antibacterial agents. Use of this vaccine should be postponed until at least 3 days after cessation of antibacterial agents. Consider therapy modification

Adverse Reactions

>10%:

Local: Injection site reaction (intramuscular: 11%; includes sterile abscess, necrosis, pain, induration)

Renal: Renal insufficiency (29%), increased serum creatinine (24%)

1% to 10%:

Cardiovascular: Hypotension (5%)

Central nervous system: Confusion (≤2%), hallucinations (≤2%)

Dermatologic: Skin rash (3%)

Endocrine & metabolic: Hypoglycemia (6%)

Gastrointestinal: Anorexia (≤6%), nausea (≤6%), dysgeusia (2%)

Hematologic & oncologic: Leukopenia (10%), thrombocytopenia (3%), anemia (1%)

Hepatic: Increased liver enzymes (9%)

Renal: Azotemia (9%), increased blood urea nitrogen (7%)

<1%, postmarketing, and/or case reports: Abdominal pain, acute pancreatitis, acute rhinitis, ageusia, amnesia, anaphylaxis, anosmia, anxiety, arthralgia, asthma, blepharitis, blurred vision, bronchitis, bronchospasm, cardiac arrhythmia, cerebrovascular accident, chest congestion, chest tightness, chills, confusion, conjunctivitis, contact lens intolerance, cough, cyanosis, depression, dermatitis, desquamation, diabetes mellitus, diabetic ketoacidosis, diarrhea, disseminated intravascular coagulation, dizziness, drowsiness, dry hair, dyspepsia, dyspnea, emotional lability, eosinophilia, eosinophilic pneumonitis, erythema, extravasation (tissue ulceration, necrosis, and/or sloughing), eye pain, flank pain, gag reflex, hair breakage, headache, hearing loss, hematochezia, hematuria, hemoptysis, hepatic insufficiency, hepatitis, hepatomegaly, hyperglycemia, hyperkalemia, hypersensitivity reaction, hypertension, hyperventilation, hypocalcemia, hypoesthesia, hypomagnesemia, insomnia, interstitial pneumonitis, laryngitis, laryngospasm, melena, nasal congestion, nephritis, nervousness, neuralgia, neuropathy, neutropenia, night sweats, palpitations, pancreatitis, pancytopenia, paranoia, paresthesia, peripheral neuropathy, phlebitis, pleurisy, pneumothorax, prolonged prothrombin time, pruritus, pulmonary disease, rales, renal failure, renal insufficiency, rhinitis, seizure, serious infection (extrapulmonary pneumocystosis), sialorrhea, splenomegaly, Stevens-Johnson syndrome, ST segment changes on ECG, syncope, tachycardia, tachypnea, torsades de pointes, tremor, unsteady gait, urinary incontinence, urticaria, vasodilation, vasculitis, ventricular tachycardia, vertigo, vomiting, xeroderma, xerostomia

Warnings/Precautions

Concerns related to adverse effects:

• Hypotension: Severe hypotension (some fatalities) has been observed, even after a single dose. May occur with either IV or IM administration, although more common with rapid IV administration. Monitor blood pressure during (and after) infusion.

• QT prolongation: May cause QT prolongation and subsequent torsade de pointes; avoid use in patients with diagnosed or suspected congenital long QT syndrome.

• Stevens-Johnson syndrome: Has been reported with use.

Disease-related concerns:

• Cardiovascular disease: Use with caution in patients with preexisting cardiovascular disease; hyper-/hypotension and arrhythmia, including ventricular tachycardia (eg, torsade de pointes) have been reported.

• Diabetes: Use with caution in patients with diabetes mellitus; hyper-/hypoglycemia and pancreatic islet cell necrosis with hyperinsulinemia has been reported. Symptoms may occur months after therapy; monitor blood glucose daily on therapy and periodically thereafter.

• Extravasation: Intravenous pentamidine is an irritant with vesicant-like properties. Ensure proper needle or catheter placement prior to and during infusion; avoid extravasation. Ulceration, tissue necrosis, and/or sloughing have been reported with extravasation.

• Hematologic disorders: Use with caution in patients with current evidence and/or prior history of hematologic disorders; anemia, leukopenia and/or thrombocytopenia have been reported. Concurrent use with other bone marrow suppressants may increase the risk for myelotoxicity.

• Hepatic impairment: Use with caution in patients with hepatic impairment.

• Hypocalcemia: Use with caution in patients with hypocalcemia.

• 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 pentamidine if signs/symptoms of acute pancreatitis occur.

• Renal impairment: Use with caution in patients with renal impairment.

Concurrent drug therapy issues:

• Drugs with QT prolongation potential: Avoid concurrent use with other drugs known to prolong QTc interval.

• Nephrotoxic drugs: Concurrent use with other nephrotoxic drugs may increase the risk for nephrotoxicity.

Monitoring Parameters

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

Pregnancy Risk Factor

C

Pregnancy Considerations

Pentamidine crosses the human placenta (Fortunato 1989; Schwebke 1995).

Intravenous pentamidine can be used as an alternative treatment in pregnant females with HIV infection for mild to moderate Pneumocystis jirovecii pneumonia (HHS [OI adult 2020]). Pentamidine may be used to treat stage one trypanosomiasis caused by T. brucei gambiense (CDC 2016); information related to treatment of pregnant females for this indication is limited (Pohlig 2016).

Patient Education

What is this drug used for?

• It is used to treat Pneumocystis jirovecii pneumonia.

• It may be given to you for other reasons. Talk with the doctor.

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:

• Nausea

• 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:

• 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.

• 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.

• 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.

• Infection

• Abnormal heartbeat

• Severe dizziness

• Passing out

• Bruising

• Bleeding

• Severe loss of strength and energy

• Severe injection site redness, swelling, blisters, burning, pain, or irritation

• 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.