Gemcitabine HCL

A to Z Drug Facts

Actions Gemcitabine exhibits cell phase specificity, primarily killing cells undergoing DNA synthesis in the S-phase. It also blocks the progression of cells through the G1/S-phase boundary. Patients achieve steady state after 15 to 30 min, during the 30-min infusion protocol. Plasma protein binding of gemcitabine is negligible. A volume of distribution is 50 L/m² following short infusions (< 70 min). For long infusions, the volume of distribution is 370 L/m². It is metabolized intracellularly to the active diphosphate and triphosphate nucleosides. Half-life ranges from 32 to 94 min for short infusions and 245 to 638 min for long infusions.

 Indications Locally advanced or metastatic pancreatic adenocarcinoma in patients previously treated with 5-fluorouracil; locally advanced or metastatic non-small cell lung cancer.

Bladder cancer; biliary cancer; metastatic breast cancer; relapsed or refractory testicular cancer; squamous cell carcinoma of the head and neck; ovarian cancer.

 Contraindications Standard considerations.

 Route/Dosage

Pancreatic Adenocarcinoma

ADULTS: IV Cycle 1: 1000 mg/m² once weekly for 7 wk followed by 1 wk of rest. Subsequent cycles: Give the same dose once weekly for 3 consecutive wk followed by 1 wk of rest. After ³ 7 doses (1 cycle), the dose may be increased to 1250 mg/m² once weekly for 3 wk, followed by 1 wk of rest, if the following criteria are met:

• Nonhematologic toxicity is no greater than WHO Grade 1,
• Platelet nadirs are > 100,000 × 10⁶/L,
• The absolute neutrophil count nadir is > 1500 × 10⁶/L.

If the patient still meets the above criteria after receiving 3 doses of the higher regimen, the gemcitabine dose may be increased to 1500 mg/m² IV once weekly for 3 wk, followed by 1 wk of rest.

Non-Small Cell Lung Cancer

ADULTS: IV In combination with cisplatin: 1000 mg/m² gemcitabine on days 1, 8, and 15 of each 28-day cycle. Alternately, 1250 mg/m² gemcitabine may be given IV on days 1 and 8 of a 21-day cycle.

Dosage Adjustment

ADULTS: Reduce or delay the gemcitabine dose in patients with neutropenia or thrombocytopenia on the day of treatment. On the day of the scheduled dose, if the absolute granulocyte count is 500 to 99 × 10⁶/L or the platelet count is 50,000 to 99,999 × 10⁶/L, then give 75% of the prior dose. If the absolute granulocyte count is < 500 × 10⁶/L or the platelet count is < 50,000 × 10⁶/L, then hold dose.

For grade 3 or 4 nonhematologic toxicity, hold gemcitabine or reduce the dose by 50% in patients with non-small cell lung cancer. Dosage reduction is not required for severe alopecia or nausea and vomiting.

Dosage reduction may be necessary in impaired renal or hepatic function. Use additional caution in these patients.

Interactions No specific drug interactions have been reported.

Lab Test Interferences None well documented.

 Adverse Reactions

CARDIOVASCULAR: MI, arrhythmia, and hypertension have occurred in patients with a past history of cardiovascular disease. CNS: Headache; mild paresthesias. DERMATOLOGIC: Minimal alopecia; rash (usually maculopapular and pruritic). GI: Moderate-to-low potential for severe nausea and vomiting; mild nausea and vomiting; diarrhea; stomatitis; elevated liver function tests. GU: Proteinuria and hematuria. HEMATOLOGIC: Myelosuppression eg, (anemia, leukopenia, granulocytopenia, thrombocytopenia) is the dose-limiting adverse effect with a nadir at 8 to 15 days. RESPIRATORY: Dyspnea. OTHER: Flu-like syndrome (eg, fever, asthenia, anorexia, headache, cough, chills, myalgia).

 Precautions

Pregnancy: Category D. Lactation: Undetermined. Children: Safety and efficacy not established. Extravasation: Local irritation or phlebitis may occur. Refer to your institution-specific protocol. Fever: The overall incidence of fever was 41%. Rash: Rash was reported in 30% of patients. The rash was typically a macular or finely granular maculopapular pruritic eruption of mild-to-moderate severity involving the trunk and extremities. Pruritus was reported in 13% of patients. Hepatic: Gemcitabine was associated with transient elevations of serum transaminases in » 70% of patients. Renal: Mild proteinuria and hematuria were commonly reported. Renal failure may not be reversible even with discontinuation of therapy, and dialysis may be required.

 Administration/Storage

• Store at controlled room temperature. Reconstituted solutions are stable for up to 24 hr at controlled room temperature. Do not refrigerate reconstituted product as crystals may form in the bag or bottle.
• Reconstitute with preservative-free 0.9% Sodium Chloride.
• Reconstituted solution may be administered directly or it may be further diluted with 0.9% Sodium Chloride to a final gemcitabine concentration ³ 0.1 mg/mL.
• Administer by IV infusion over 30 min.
• Prolonging infusions past 60 min increases the risk of myelosuppression.

 Assessment/Interventions

• Monitor complete blood counts at baseline and prior to each gemcitabine dose.
• Monitor renal and hepatic function at baseline and periodically throughout therapy.
• Female patients and the elderly may eliminate gemcitabine more slowly, increasing the risk of adverse effects.

 Patient/Family Education

• Contact health care provider if any of the following occurs: a temperature > 100.4°F or shaking chills; unusual bruising or bleeding; pain around an infusion site; sore mouth or throat; prolonged or uncomfortable swelling; severe diarrhea; severe constipation; numbness or tingling in the hands or feet; vomiting for > 24 hr after the treatment; any changes in the skin.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts