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Pentamidine (Systemic)

Pronunciation

(pen TAM i deen)

Index Terms

  • Pentamidine Isethionate

Dosage Forms

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

Solution Reconstituted, Injection, as isethionate:

Pentam: 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)

Contraindications

Hypersensitivity to pentamidine isethionate or any component of the formulation

Dosing: Adult

Pneumocystis jirovecii pneumonia (PCP), treatment:

Manufacturer labeling: IM, IV: 4 mg/kg once daily for 14 to 21 days

HIV-infected patients (alternative to preferred therapy): IV: 4 mg/kg/dose once daily for 21 days; may reduce to 3 mg/kg/dose once daily if toxicity occurs (HHS [OI adult 2015])

Trypanosomiasis (off-label use): IM, IV: 4 mg/kg once daily for 7 to 10 days (CDC 2013)

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Pneumocystis jirovecii pneumonia (PCP), prophylaxis (primary and secondary) in oncology patients (including HSCT recipients) (off-label use): 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])

Pneumocystis jirovecii pneumonia (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 (HHS [OI pediatric 2013])

Adolescents: IV: Refer to adult dosing.

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) (off-label use): Infants, Children, Adolescents, and Adults: IM, IV: 4 mg/kg/dose once daily for 7 to 10 days (Bradley 2015; CDC 2013; Red Book [AAP 2015])

Dosing: Renal Impairment

IV: The FDA-approved labeling recommends that caution should be used in patients with renal impairment; however, no specific dosage adjustment guidelines are available. The following guidelines have been used by some clinicians (Aronoff 2007):

Adults:

CrCl ≥10 mL/minute: No dosage adjustment necessary.

CrCl <10 mL/minute: Administer 4 mg/kg every 24 to 36 hours.

Children:

CrCl >30 mL/minute: No dosage adjustment necessary.

CrCl 10 to 30 mL/minute: Administer 4 mg/kg every 36 hours.

CrCl <10 mL/minute and peritoneal dialysis: Administer 4 mg/kg every 48 hours.

Hemodialysis: Administer 4 mg/kg every 48 hours, after dialysis on dialysis days.

Dosing: Hepatic Impairment

There are no dosage adjustments provided in the manufacturer’s labeling (has not been studied). Use with caution.

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).

Compatibility

Stable in D5W, NS (do not use NS for initial reconstitution)

Y-site administration: Incompatible with aldesleukin, cefazolin, cefotaxime, cefoxitin, ceftazidime, ceftriaxone, fluconazole, foscarnet, linezolid.

Compatibility in syringe: Incompatible with ceftriaxone.

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

Androgens: May enhance the hypoglycemic effect of Blood Glucose Lowering Agents. 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. 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

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

Highest Risk QTc-Prolonging Agents: Moderate Risk QTc-Prolonging Agents may enhance the QTc-prolonging effect of Highest Risk QTc-Prolonging Agents. Avoid combination

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

Ivabradine: May enhance the QTc-prolonging effect of Moderate Risk QTc-Prolonging Agents. Avoid combination

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

MAO Inhibitors: May enhance the hypoglycemic effect of Blood Glucose Lowering Agents. 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

MiFEPRIStone: May enhance the QTc-prolonging effect of Moderate Risk QTc-Prolonging Agents. Avoid combination

Moderate Risk QTc-Prolonging Agents: May enhance the QTc-prolonging effect of other Moderate Risk QTc-Prolonging Agents. Management: Avoid such combinations when possible. Use should be accompanied by close monitoring for evidence of QT prolongation or other alterations of cardiac rhythm. Consider therapy modification

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

QTc-Prolonging Agents (Indeterminate Risk and Risk Modifying): May enhance the QTc-prolonging effect of Moderate Risk QTc-Prolonging Agents. Monitor therapy

Quinolone Antibiotics: May enhance the hypoglycemic effect of Blood Glucose Lowering Agents. Quinolone Antibiotics may diminish the therapeutic effect of Blood Glucose Lowering Agents. 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 Blood Glucose Lowering Agents. Monitor therapy

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

Vinflunine: May enhance the QTc-prolonging effect of Moderate Risk QTc-Prolonging Agents. Avoid combination

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% (Limited to important or life-threatening): Abdominal pain, acute pancreatitis, acute rhinitis, ageusia, amnesia, anosmia, anxiety, arthralgia, blepharitis, blurred vision, bronchitis, cardiac arrhythmia, cerebrovascular accident, chest congestion, chest tightness, chills, confusion, conjunctivitis, cyanosis, depression, dermatitis, desquamation, diabetes mellitus, diabetic ketoacidosis, diarrhea, disseminated intravascular coagulation, dizziness, drowsiness, dry hair, dyspepsia, dyspnea, emotional lability, eosinophilia, eosinophilic pneumonitis, erythema, extrapulmonary pneumocystosis, 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, 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, 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

Animal reproduction studies were not conducted by the manufacturer. Pentamidine crosses the human placenta (Fortunato 1989). Intravenous pentamidine can be used as an alternative treatment in pregnant HIV-infected women with mild to moderate Pneumocystis jirovecii pneumonia (HHS [OI; adult] 2015).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience nausea or lack of appetite. Have patient report immediately to prescriber signs of liver problems (dark urine, feeling tired, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or yellow skin or eyes), signs of kidney problems (urinary retention, blood in urine, change in amount of urine passed, or weight gain), signs of low blood sugar (dizziness, headache, fatigue, feeling weak, shaking, a fast heartbeat, confusion, hunger, or sweating), signs of high blood sugar (confusion, feeling sleepy, more thirst, hunger, passing urine more often, flushing, fast breathing, or breath that smells like fruit), signs of low calcium (muscle cramps or spasms, numbness and tingling, or seizures), signs of pancreatitis (severe abdominal pain, severe back pain, severe nausea, or vomiting), signs of high potassium (abnormal heartbeat, confusion, dizziness, passing out, weakness, shortness of breath, numbness or tingling feeling), arrhythmia, severe dizziness, passing out, chills, pharyngitis, bruising, bleeding, severe loss of strength and energy, severe injection site redness, edema, blisters, burning, pain or irritation (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.

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