Pentamidine injection (Pentam) is an anti-protozoal medicine that is used for the prophylaxis and treatment of Pneumocystis Jirovecii Pneumonia.

Pentamidine injection (Pentam) Uses:

• Treatment of pneumonia caused by Pneumocystis jirovecii pneumonia (PCP)

• Off Label Use of Pentamidine in Adults:

  • Trypanosomiasis
  • Prevention of PCP in non-HIV-infected patients

Pentamidine injection Dose in Adults

Pentamidine injection Dose as alternative agent in the treatment of Pneumocystis jirovecii pneumonia (PCP):

• IV: 4 mg/kg/dose once a day (manufacturer's labeling) for 21 days;
• The dose may be reduced to 3 mg/kg/dose once a day if toxicity occurs

Pentam Dose in the treatment of Trypanosomiasis (off-label):

• IM, IV: 4 mg/kg once a day for 7 to 10 days

Pentamidine injection Dose in Childrens

Pentamidine injection Dose for the primary and secondary prophylaxis of Pneumocystis jirovecii (PCP) infection in oncology patients (including HSCT recipients):

• Note: For patients intolerant to sulfamethoxazole and trimethoprim.

• Children ≥2 years and Adolescents:

  • IV: 4 mg/kg/dose once a month; in HSCT recipient doses have been administered every 2 to 4 weeks

Pentamidine injection Dose in the treatment of moderate to severe PCP:

• Note: For patients who are unable to tolerate or who failed 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 a day for 14 to 21 days

• HIV-exposed/-positive:

  • Infants and Children:
    • IV: 4 mg/kg/dose once every day;
    • if clinical improvement occurs after 7 to 10 days of therapy, may change to an oral regimen to complete a 21-day course
  • Adolescents:
    • IV: 4 mg/kg/dose once a day for 21 days; some experts recommend a dose reduction to 3 mg/kg/dose for toxicity

• Non-HIV-exposed/-positive:

  • Infants, Children, and Adolescents:
    • IV: 3 to 4 mg/kg/dose once a day for 21 days

Pentamidine Injection Dose in the treatment of Trypanosomiasis (non-CNS disease):

• Infants, Children, and Adolescents:

  • IM, IV: 4 mg/kg/dose once a day for 7 to 10 days

Pregnancy Risk Factor C

• Pentamidine crosses over the human placenta.
• For mild to moderate Pneumocystis Jirovecii pneumonia, intravenous pentamidine may be an alternative treatment for pregnant women with HIV infection.
• Pentamidine could be used to treat stage one trypanosomiasis due to T.brucei.gambiense.
• This indication does not have much information.

Use of pentamidine during breastfeeding

• It is unknown if pentamidine can be found in breast milk.
• The drug manufacturer suggests that mothers consider whether to stop breastfeeding or discontinue using the drug.
• This is in consideration of the possibility of serious adverse reactions in breastfeeding infants.
• To reduce the risk of HIV transmission, pregnant women with HIV should stop breastfeeding.

Pentamidine Injection Dose in Kidney Disease:

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

  • CrCl ≥10 mL/minute:

    • No dosage adjustment is necessary.

  • CrCl <10 mL/minute:

    • Administer 4 mg/kg every 24 to 36 hours.

Pentamidine Injection Dose in Liver Disease:

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

Common Side Effects of Pentamidine Injection (Pentam):

• Local:

  • Injection site reaction

• Renal:

  • Renal insufficiency
  • increased serum creatinine

Less Common Side Effects of Pentamidine Injection (Pentam):

• Cardiovascular:

  • Hypotension

• Central nervous system:

  • Confusion
  • hallucinations

• Dermatologic:

  • Skin rash

• Endocrine & metabolic:

  • Hypoglycemia

• Gastrointestinal:

  • Anorexia
  • nausea
  • dysgeusia

• Hematologic & oncologic:

  • Leukopenia
  • thrombocytopenia
  • anemia

• Hepatic:

  • Increased liver enzymes

• Renal:

  • Azotemia
  • increased blood urea nitrogen

Contraindication to Pentam (Pentamidine Injection):

• Hypersensitivity/Allergy to pentamidine isethionate or any component of the formulation

Warnings and precautions

• Hypotension

  • Even after one dose, severe hypotension (some fatalities), has been reported.
  • It can occur with IV or IM administration. However, it is more common with rapid intravenous (IV) administration.
  • Monitor your blood pressure before and after infusions.

• Extension of QT

  • QT prolongation and subsequent Torsade de Pointes.
  • Avoid use in patients suffering from congenital long QT syndrome.

• Stevens-Johnson syndrome:

  • It has been reported as being used.

• Cardiovascular disease

  • Patients with pre-existing cardiovascular disease should be cautious.
  • Hypertension, arrhythmia and hyper/hypotension, including ventricular Tachycardia (eg torsade des pointes), have been reported.

• Diabetes:

  • Patients with diabetes mellitus should be cautious. Hyper-/hypoglycemia, pancreatic islet cell necrosis and hyperinsulinemia were reported.
  • You may experience symptoms for several months. Monitor your blood glucose daily while you are on therapy and every other day thereafter.

• Extravasation:

  • Intravenous pentamidine can be an irritant that has vesicant-like characteristics.
  • Make sure you place the catheter or needle correctly before and during infusion.
  • Extravasation has been associated with sloughing, tissue necrosis and/or ulceration.

• Hematologic disorders

  • Patients with a history and/or current evidence of hematologic disorders should be cautious.
  • Myelotoxicity may be increased by concurrent use of other bone marrow suppressant drugs.

• Hepatic impairment

  • Patients with hepatic impairment should be cautious.

• Hypocalcemia:

  • Hypocalcemia patients should be treated with caution.

• Pancreatitis

  • Patients with a history or elevated levels of amylase/lipase should be cautious.
  • Reports of acute pancreatitis with fatalities have been made.
  • If you develop signs or symptoms of acute pancreatitis, stop taking pentamidine.

• Renal impairment

  • Patients with impaired renal function should be cautious.

Pentamidine (systemic): Drug Interaction

Note: Drug Interaction Categories:

• Risk Factor C: Monitor When Using Combination
• Risk Factor D: Consider Treatment Modification
• Risk Factor X: Avoid Concomitant Use

Monitoring Parameters:

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

How to administer Pentamidine Injection (Pentam)?

• 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 before and during infusion.
• Avoid extravasation.

Extravasation management:

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

Mechanism of action of Pentamidine Injection (Pentam):

• Interferes in microbial DNA/DNA, phospholipids, and protein synthesis through inhibition of oxidativephosphorylation, and/or interference at the incorporation nucleotides or nucleic acids into DNA and RNA

Absorption:

• IM: Well absorbed

Distribution:

• It binds to plasma proteins and tissues; high levels are found in the liver and kidneys, adrenals and spleens, lungs and pancreas. CNS penetration is poor.

Half-life elimination:

• IV: 5 to 8 hours;
• IM: 7 to11 hours;
• may be prolonged with severe renal impairment

Excretion:

• Urine (IV: ≤12% as unchanged drug)

International Brands of Pentamidine Injection:

• Pentam

Pentamidine Brand Names in Pakistan:

No Brands Available in Pakistan.