topotecan hydrochloride
Pharmacologic class: DNA topoisomerase inhibitor
Therapeutic class: Antineoplastic
Pregnancy risk category D
FDA Box Warning
Give under supervision of physician experienced in cancer chemotherapy, in facility with adequate diagnostic and treatment resources.
Don't administer to patients with baseline neutrophil counts below 1,500 cells/mm3. Obtain frequent peripheral blood cell counts on all patients to monitor for bone marrow depression.
Action
Regulates DNA replication and repair of broken DNA strands, relieving torsional strain; exerts cytotoxic effects during DNA synthesis
Availability
Capsules: 0.25 mg, 1 mg
Injection: 4 mg in 4-ml single-dose vials
Injection (powder for solution): 4 mg in single-dose vials
Indications and dosages
➣ Metastatic ovarian cancer or small-cell lung cancer after first-line chemotherapy fails
Adults: 1.5 mg/m2 daily by I.V. infusion given over 30 minutes for 5 consecutive days, starting on day 1 of 21-day cycle
➣ Relapsed small-cell lung cancer
Adults: 2.3 mg/m2 P.O. daily for 5 consecutive days; repeat every 21 days
➣ Stage IV-B, recurrent, or persistent cervical carcinoma not amenable to curative treatment with surgery or radiation therapy (in combination with cisplatin)
Adults: 0.75 mg/m2 I.V. daily over 30 minutes on days 1, 2, and 3; followed by cisplatin 50 mg/m2 by I.V. infusion on day 1, repeated every 21 days
Dosage adjustment
• Renal impairment
• Neutropenia
• Grade 3 or 4 diarrhea (capsules)
Contraindications
• History of severe hypersensitivity to drug or its components
• Severe bone marrow depression
Precautions
Use cautiously in:
• pregnant or breastfeeding patients
• children (safety and efficacy not established).
Administration
Before starting therapy, check blood counts. Patient must have baseline neutrophil count above 1,500 cells/mm3 and platelet count above 100,000 cells/mm3 to receive drug.
Prepare drug under vertical laminar-flow hood, wearing gloves and protective clothing. Follow facility policy for discarding used drug containers and I.V. equipment.
• If skin contacts drug, wash immediately with soap and water.
• To reconstitute, add 4 ml of sterile water to 4-mg vial. Dilute further in normal saline solution or dextrose 5% in water. Give immediately over 30 minutes using infusion pump.
• Round calculated oral daily dose to nearest 0.25 mg, and administer minimum number of 1-mg and 0.25-mg capsules. Know that the same number of capsules should be prescribed for each of the 5 dosing days.
Adverse reactions
CNS: asthenia, fatigue, paresthesia
GI: nausea, diarrhea, constipation, abdominal pain, stomatitis, anorexia, severe diarrhea, neutropenic colitis
Hematologic: anemia, leukopenia, thrombocytopenia, neutropenia
Musculoskeletal: back pain, skeletal pain
Respiratory: coughing, dyspnea, interstitial lung disease
Skin: erythematous or maculopapular rash, pruritus, urticaria, dermatitis, bullous eruption, alopecia
Other: fever, body pain, sepsis
Interactions
Drug-drug. Cisplatin: severe bone marrow depression
Granulocyte colony-stimulating factor: prolonged neutropenia
Live-virus vaccines: increased risk of infection from vaccine
Drug-diagnostic tests. Alanine aminotransferase, aspartate aminotransferase, bilirubin: increased levels
Patient monitoring
• Closely monitor CBC with white cell differential.
Assess for signs and symptoms of bleeding tendency, severe diarrhea (with capsule use), and neutropenic colitis (fever, neutropenia, and compatible pattern of abdominal pain).
Monitor patient for signs and symptoms of interstitial lung disease (cough, fever, dyspnea, or hypoxia); discontinue drug if diagnosis is confirmed.
• Monitor closely for sepsis, other infections, and increased hepatic enzyme levels.
Patient teaching
• Tell patient to take capsules whole with or without food and not to break, divide, chew, or crush them.
Advise patient to immediately report unusual bleeding or bruising, diarrhea, abdominal pain, cough, difficulty breathing, sore throat, fever, or chills.
• Teach patient safety measures to avoid bruising and bleeding.
• Tell patient to minimize GI upset by eating small, frequent servings of food and drinking plenty of fluids.
Advise female patient to notify prescriber of suspected pregnancy. Caution her not to breastfeed during therapy.
• Inform patient that drug may cause hair loss.
• Tell patient he'll undergo regular blood testing during therapy.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.