Nurses Compass
Drug Guide
Pentamidine Isethionate
Classification
Therapeutic: Antiprotozoal, Antifungal
Pharmacological: Pentamidine is a DNA-binding agent that inhibits nuclear and mitochondrial DNA synthesis
FDA Approved Indications
- Treatment of Pneumocystis jirovecii pneumonia (PCP) in immunocompromised patients
- Prophylaxis of PCP in high-risk populations
Mechanism of Action
Pentamidine binds to DNA, disrupting its function and inhibiting the synthesis of RNA and proteins, leading to parasite cell death.
Dosage and Administration
Adult: Dosage varies; typically 4 mg/kg administered via inhalation every 4 weeks for prophylaxis, or as directed for treatment. Intravenous doses are usually 4 mg/kg twice weekly, but must be individualized.
Pediatric: Use is off-label; dosing should be determined by a specialist, generally similar to adult dosing adjusted for weight and clinical response.
Geriatric: Caution advised; lower doses or increased monitoring may be necessary due to renal or hepatic impairment.
Renal Impairment: Adjust dosage; monitor renal function regularly.
Hepatic Impairment: Use with caution; monitor liver function.
Pharmacokinetics
Absorption: Poorly absorbed via oral route; administered parenterally or via inhalation.
Distribution: Widely distributed in body tissues, including lungs, kidneys, and liver.
Metabolism: Metabolized minimally; primarily excreted unchanged.
Excretion: Renal excretion predominates.
Half Life: Approximately 6 hours in plasma.
Contraindications
- Hypersensitivity to pentamidine or other aromatic diamidines
Precautions
- Use cautiously in patients with renal impairment, hepatic impairment, cardiovascular disease, or blood dyscrasias. Monitor blood glucose in diabetics, as hypoglycemia or hyperglycemia may occur. Parsing of potential drug interactions necessary.
Adverse Reactions - Common
- Altered taste, nausea, vomiting (Common)
- Nephrotoxicity (Common)
Adverse Reactions - Serious
- Pancreatitis (Rare)
- Hypoglycemia or hyperglycemia (Rare)
- Bone marrow suppression (pancytopenia) (Rare)
- Hypotension, arrhythmias (Rare)
Drug-Drug Interactions
- Caution with other nephrotoxic drugs like aminoglycosides, NSAIDs.
- Potential interaction with drugs affecting blood sugar.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor renal function (BUN, serum creatinine), blood glucose, and blood counts regularly.
Diagnoses:
- Risk of renal impairment
- Risk of hypoglycemia or hyperglycemia
- Risk of infection due to bone marrow suppression
Implementation: Administer as prescribed, monitor for adverse reactions, provide hydration, and ensure proper PPE during inhalation therapy.
Evaluation: Assess for resolution or improvement of PCP, monitor lab results, and observe for adverse effects.
Patient/Family Teaching
- Report symptoms of kidney problems, blood disorders, or allergic reactions immediately.
- Ensure understanding of the importance of adherence to dosing schedule.
- Maintain hydration during therapy.
Special Considerations
Black Box Warnings:
- Potential for severe renal toxicity and pancreatic toxicity.
- Caution advised due to toxic effects.
Genetic Factors: No specific genetic considerations reported.
Lab Test Interference: May alter liver function tests, renal function tests, and hematologic tests.
Overdose Management
Signs/Symptoms: Severe hypotension, renal failure, hypoglycemia or hyperglycemia, pancytopenia.
Treatment: Supportive care, dialysis if necessary, manage blood glucose levels, and monitor renal function.
Storage and Handling
Storage: Store at room temperature, away from moisture and light.
Stability: Stable for approved shelf life when stored properly.