Home Drug Guide Gemcitabine Hydrochloride

Drug Guide

Generic Name

Gemcitabine Hydrochloride

Brand Names Gemzar, Infugem

Classification

Therapeutic: Antineoplastic agent (cancer chemotherapy)

Pharmacological: Antimetabolite (nucleoside analog)

FDA Approved Indications

Non-small cell lung cancer (NSCLC)
Pancreatic cancer
Bladder cancer
Breast cancer (metastatic)

Mechanism of Action

Gemcitabine is a nucleoside analog that inhibits DNA synthesis by incorporating into DNA strands and inhibiting DNA polymerase, leading to apoptosis of dividing cells.

Dosage and Administration

Adult: Dose varies based on indication; typically 1000-1250 mg/m² IV on days 1, 8, and 15 of a 28-day cycle.

Pediatric: Safety and efficacy not established; use is off-label and individualized.

Geriatric: Use with caution; consider comorbidities and renal/hepatic function.

Renal Impairment: Adjust dose based on renal function; consult specific guidelines.

Hepatic Impairment: Use with caution; no specific adjustments established.

Pharmacokinetics

Absorption: Given IV; not absorbed orally.

Distribution: Widely distributed, crosses the placenta, enters cerebrospinal fluid.

Metabolism: Metabolized intracellularly to active metabolites; undergoes deamination.

Excretion: Primarily renal excretion of metabolites.

Half Life: Approximately 42 minutes (intravenous form).

Contraindications

Hypersensitivity to gemcitabine or any component of the formulation.

Precautions

Monitor blood counts closely; risk of myelosuppression.
Use with caution in hepatic or renal impairment.
Pregnancy category D; use caution during pregnancy and lactation.

Adverse Reactions - Common

Myelosuppression (neutropenia, thrombocytopenia, anemia) (Very common)
Nausea, vomiting (Common)
Malaise, fatigue (Common)
Elevations in liver enzymes (Common)

Adverse Reactions - Serious

Severe myelosuppression leading to infections or bleeding (Less common but serious)
Maximum toxicity includes pulmonary toxicity, hepatic failure, or capillary leak syndrome (Rare but serious)
Allergic reactions (rash, fever, hypotension) (Rare)

Drug-Drug Interactions

CYP1A2 inducers (e.g., rifampin) may increase metabolism of gemcitabine.
Cytotoxic agents may have additive myelosuppressive effects.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor complete blood counts, liver and renal function, signs of toxicity.

Diagnoses:

Risk for infection due to myelosuppression
Risk for bleeding
Impaired tissue integrity

Implementation: Administer IV as prescribed; monitor infusion sites.

Evaluation: Assess hematologic parameters regularly; evaluate patient for signs of toxicity.

Patient/Family Teaching

Report signs of infection, bleeding, or unusual fatigue.
Follow instructions on managing nausea and other side effects.
Avoid pregnancy; use effective contraception.
Report any allergic reactions or symptoms of pulmonary toxicity.

Special Considerations

Black Box Warnings:

Severe embryo-fetal toxicity; pregnancy must be avoided during treatment.
Myelosuppression that can be severe and sometimes fatal.

Genetic Factors: No specific genetic testing required, but pharmacogenetics for efficacy/toxicity is under research.

Lab Test Interference: May cause false elevations of serum creatinine.

Overdose Management

Signs/Symptoms: Severe myelosuppression, neurologic symptoms (e.g., cerebellar signs), or allergic reactions.

Treatment: Supportive care with hematopoietic growth factors, transfusions as needed, and symptomatic management.

Storage and Handling

Storage: Store at 2-8°C (refrigerate).

Stability: Stable until the expiration date; protect from light.