Etoposide should only be administered and monitored under the supervision of a qualified physician experienced in the use of anti-neoplastic medicinal products. In all instances where the use of etoposide is considered for chemotherapy, the physician must evaluate the need and usefulness of the drug against the risk of adverse reactions. Most such adverse reactions are reversible if detected early. If severe reactions occur, the drug should be reduced in dosage or discontinued, and appropriate corrective measures should be taken according to the clinical judgment of the physician. Reinstitution of etoposide therapy should be carried out with caution, and with adequate consideration of the further need for the drug and close attention to possible recurrence of toxicity.
Within-patient variability
The available efficacy data for etoposide in the different indications are generally based on studies in which etoposide was used intravenously. Within-patient variability in exposure (i.e. between cycles) is larger with oral administration than after intravenous administration. The coefficient of variation is around 30% after oral administration versus 10% after intravenous administration (between-patient variability is similar after intravenous or oral administration, i.e. 30 to 40%). Increased within-patient variability in exposure may lead to greater variability in the dose-response relationship, i.e., leading to greater variability in patients' sensitivity to experience treatment-related toxicity from cycle to cycle, and potentially affecting overall efficacy of treatment in some patients. For this reason, it is critical that the advantages of the oral administration route are carefully weighed against the disadvantages of larger within-patient variability in exposure after oral administration. In case of curative intent, the intravenous formulation should be used (see section 5.2).
Myelosuppression
Dose limiting bone marrow suppression is the most significant toxicity associated with etoposide therapy. Fatal myelosuppression has been reported following etoposide administration. Patients being treated with etoposide must be observed for myelosuppression carefully and frequently both during and after therapy. The following haematological parameters should be measured at the start of therapy and prior to each subsequent dose of etoposide: platelet count, haemoglobin, white blood cell count and differential. If radiotherapy or chemotherapy has been given prior to starting etoposide treatment, an adequate interval should be allowed to enable the bone marrow to recover. Etoposide should not be administered to patients with neutrophil counts less than 1,500 cell/mm3 or platelet counts less than 100,000 cells/mm3, unless caused by malignant disease. Doses subsequent to initial dose should be adjusted if neutrophil count less than 500 cells/mm3 occurs for more than 5 days or is associated with fever or infection, if platelet count less than 25,000 cells/mm3 occurs, if any grade 3 or 4 toxicity develops or if renal clearance is less than 50 ml/min.
Severe myelosuppression with resulting infection or haemorrhage may occur. Bacterial infections should be brought under control before treatment with etoposide.
Secondary leukaemia
The occurrence of acute leukaemia, which can occur with or without myelodysplastic syndrome, has been described in patients that were treated with etoposide containing chemotherapeutic regimens. Neither the cumulative risk, nor the predisposing factors related to the development of secondary leukaemia are known. The roles of both administration schedules and cumulative doses of etoposide have been suggested but have not been clearly defined.
An 11q23 chromosome abnormality has been observed in some cases of secondary leukaemia in patients who have received epipodophyllotoxins. This abnormality has also been seen in patients developing secondary leukaemia after being treated with chemotherapy regimens not containing epipodophyllotoxins and in leukaemia occurring de novo. Another characteristic that has been associated with secondary leukaemia in patients who have received epipodophyllotoxins appears to be a short latency period, with average median time to development of leukaemia being approximately 32 months.
Hypersensitivity
Physicians should be aware of the possible occurrence of an anaphylactic reaction with etoposide, manifested by chills, pyrexia, tachycardia, bronchospasm, dyspnoea and hypotension, which can be fatal. Treatment is symptomatic. Etoposide should be terminated immediately, followed by the administration of pressor agents, corticosteroids, antihistamines, or volume expanders at the discretion of the physician.
Low serum albumin
Low serum albumin is associated with increased exposure to etoposide. Therefore, patients with low serum albumin may be at increased risk for etoposide-associated toxicities.
Impaired renal function
In patients with moderate (CrCl =15 to 50 mL/min), or severe (CrCl <15 mL/min) renal impairment undergoing haemodialysis, etoposide should be administered at a reduced dose (see section 4.2).
Haematological parameters should be measured and dose adjustments in subsequent cycles considered based on haematological toxicity and clinical effect in moderate and severe renal impaired patients.
Impaired hepatic function
Patients with impaired hepatic function should regularly have their hepatic function monitored due to the risk of accumulation.
Tumour lysis syndrome
Tumour lysis syndrome (sometimes fatal) has been reported following the use of etoposide in association with other chemotherapeutic drugs. Close monitoring of patients is needed to detect early signs of tumour lysis syndrome, especially in patients with risk factors such as bulky treatment- sensitive tumours, and renal insufficiency. Appropriate preventive measures should also be considered in patients at risk of this complication of therapy.
Mutagenic potential
Given the mutagenic potential of etoposide, an effective contraception is required for both male and female patients during treatment and up to 6 months after ending treatment. Genetic consultation is recommended if the patient wishes to have children after ending the treatment. As etoposide may decrease male fertility, preservation of sperm may be considered for the purpose of later fatherhood (see section 4.6).
Excipients
Etoposide contains sodium ethyl parahydroxybenzoate and sodium propyl parahydroxybenzoate
Etoposide capsules contain sodium ethyl parahydroxybenzoate and sodium propyl parahydroxybenzoate which may cause allergic reactions (possibly delayed).
Etoposide contains sodium
This medicine contains less than 1 mmol sodium (23 mg) per soft capsule, that is to say essentially 'sodium-free'.
Paediatric population
Safety and effectiveness of Etoposide in paediatric patients has not been systematically studied.