Home Drug Guide Pemetrexed

Drug Guide

Generic Name

Pemetrexed

Brand Names Alimta, Pemetrexed For Injection, Pemfexy

Classification

Therapeutic: Antineoplastic agent

Pharmacological: Antimetabolite

FDA Approved Indications

  • Non-small cell lung cancer (NSCLC)
  • Malignant pleural mesothelioma

Mechanism of Action

Pemetrexed is an antifolate chemotherapy agent that inhibits thymidylate synthase and other folate-dependent enzymes involved in purine and pyrimidine synthesis, leading to inhibition of DNA and RNA synthesis and cell death.

Dosage and Administration

Adult: Typically 500 mg/m² IV infusion on Day 1 of each 21-day cycle, as per specific treatment regimens.

Pediatric: Not commonly used in pediatric populations; dosing is based on body surface area and clinical judgment.

Geriatric: Dose adjustments are not typically required solely based on age, but caution is advised due to potential comorbidities.

Renal Impairment: Dose reduction or delay may be necessary; renal function should be assessed before each dose.

Hepatic Impairment: Use with caution; no specific dose adjustment recommended, but hepatic function should be monitored.

Pharmacokinetics

Absorption: Given IV, so absorption is not applicable.

Distribution: Widely distributed, crossing the blood-brain barrier minimally.

Metabolism: Minimal metabolism; primarily eliminated unchanged.

Excretion: Renally excreted, primarily unchanged.

Half Life: Approximately 3.5 hours.

Contraindications

  • Hypersensitivity to pemetrexed or its components.
  • Severe renal impairment (creatinine clearance < 45 mL/min).

Precautions

  • Use in pregnancy and lactation should be avoided; women should use effective contraception during treatment.
  • Monitor renal function closely.
  • Patients should receive folic acid and vitamin B12 supplements before and during treatment to reduce toxicity.

Adverse Reactions - Common

  • Myelosuppression (neutropenia, anemia, thrombocytopenia) (Common)
  • Nausea, vomiting (Common)
  • Fatigue (Common)
  • Stomatitis (mouth ulcers) (Common)

Adverse Reactions - Serious

  • Serious myelosuppression leading to infection or bleeding (Serious)
  • Interstitial pulmonary disease or pneumonitis (Serious)
  • Allergic reactions including rash, pruritus, anaphylaxis (Serious)

Drug-Drug Interactions

  • Cisplatin (co-administration increases toxicity)

Drug-Food Interactions

  • Avoid alcohol and live vaccines during treatment.

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood counts, renal function, hepatic function, and hydration status before each dose.

Diagnoses:

  • Risk for infection
  • Imbalanced nutrition: less than body requirements

Implementation: Administer with folic acid and vitamin B12 as recommended. Ensure adequate hydration and monitor for toxicity.

Evaluation: Assess patient’s tolerance, blood counts, and organ functions regularly to modify therapy as needed.

Patient/Family Teaching

  • Report signs of infection, bleeding, or allergic reactions.
  • Maintain adequate hydration.
  • Take folic acid and vitamin B12 supplements as prescribed.
  • Avoid pregnancy during therapy and for at least 6 months after.

Special Considerations

Black Box Warnings:

  • Potential for myelosuppression, which can be severe and lead to serious infections, bleeding, or neutropenic fever.
  • Risk of pulmonary toxicity, including interstitial pneumonitis.

Genetic Factors: Vitamin B12 and folic acid deficiency may increase toxicity; supplementation recommended.

Lab Test Interference: May alter blood counts, renal and hepatic function tests.

Overdose Management

Signs/Symptoms: Severe myelosuppression, mucositis, or pulmonary toxicity.

Treatment: Supportive care; no specific antidote. Hematopoietic growth factors or transfusions may be required.

Storage and Handling

Storage: Store at room temperature away from moisture and light.

Stability: Stable for the duration of the labeled expiration date when stored properly.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.