Drug Guide
Pralatrexate
Classification
Therapeutic: Antineoplastic, Antimetabolite
Pharmacological: Folate analogue metabolic inhibitor
FDA Approved Indications
- Relapsed or refractory peripheral T-cell lymphoma (PTCL)
Mechanism of Action
Pralatrexate is a folate analogue metabolic inhibitor that selectively inhibits dihydrofolate reductase (DHFR), leading to inhibition of DNA synthesis, repair, and cellular replication, primarily affecting rapidly dividing cancer cells.
Dosage and Administration
Adult: Dose: 30 mg/m² IV weekly for 6 weeks followed by 1 week of rest (total 7-week cycles). Premedicate with folic acid and vitamin B12 before starting therapy and during treatment to reduce toxicity.
Pediatric: Not typically used in pediatric patients; safety and efficacy not established.
Geriatric: Use with caution; monitor for toxicity, especially in patients with decreased renal function.
Renal Impairment: Dose modification may be necessary; consult specific guidelines.
Hepatic Impairment: No specific dose adjustment recommended; monitor hepatic function.
Pharmacokinetics
Absorption: Administered intravenously, rapid and complete absorption is not applicable.
Distribution: Widely distributed; high affinity for tissues.
Metabolism: Metabolized minimally; primarily excreted unchanged.
Excretion: Primarily renal excretion.
Half Life: Approximate half-life of 13 hours.
Contraindications
- Hypersensitivity to pralatrexate or its components.
Precautions
- Risk of myelosuppression, mucositis, infections, renal toxicity, hepatotoxicity, and pulmonary toxicity. Use with caution in pregnant or breastfeeding women. Monitor blood counts, renal and hepatic function regularly.
Adverse Reactions - Common
- Myelosuppression (neutropenia, anemia, thrombocytopenia) (Very common)
- Stomatitis/mucositis (Common)
- Nausea, vomiting (Common)
- Fatigue (Common)
Adverse Reactions - Serious
- Severe myelosuppression leading to infections or bleeding (Serious (rare))
- Renal toxicity (Serious (rare))
- Pulmonary toxicity (pneumonitis, fibrosis) (Serious (rare))
- Hepatotoxicity (Serious (rare))
Drug-Drug Interactions
- Other myelosuppressive agents, nephrotoxic drugs, hepatotoxic drugs
Drug-Food Interactions
- Folate supplements (should be managed carefully to balance efficacy and toxicity)
Drug-Herb Interactions
N/ANursing Implications
Assessment: Monitor complete blood counts, renal and hepatic function, respiratory status, and oral mucosa.
Diagnoses:
- Risk for infection
- Impaired oral mucous membrane
- Risk for bleeding
Implementation: Administer folic acid and vitamin B12 as prescribed. Ensure adequate hydration. Educate patient on mucositis and management.
Evaluation: Monitor for hematologic toxicity, mucositis, renal and hepatic adverse effects, and overall response.
Patient/Family Teaching
- Report fever, sore throat, mouth sores, or unusual bleeding.
- Maintain good oral hygiene.
- Follow dosing schedule and attend all monitoring appointments.
- Use effective contraception during treatment and for some time after.
Special Considerations
Black Box Warnings:
- Severe myelosuppression, mucositis, and renal toxicity.
Genetic Factors: N/A
Lab Test Interference: Potential interference with folate and vitamin B12 levels; interpret labs accordingly.
Overdose Management
Signs/Symptoms: Severe myelosuppression, mucositis, renal failure.
Treatment: Supportive care including blood product transfusions, growth factors, hydration, and symptomatic management. Hemodialysis may be considered in cases of toxicity.
Storage and Handling
Storage: Store at controlled room temperature, 20°C to 25°C (68°F to 77°F). Keep in original container.
Stability: Stable under recommended storage conditions until expiration date.