Drugs
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Oxaliplatin is a platinum compound that inhibits DNA synthesis, primarily by causing intrastrand cross-links in DNA. Oxaliplatin has a broad spectrum of antineoplastic activity and has demonstrated a lack of cross-resistance with other platinum compounds. In patients with metastatic colorectal cancer, intravenous oxaliplatin has been trialled as a monotherapy and in combination with other agents. The highest response rates were achieved when oxaliplatin was used in combination with fluorouracil/folinic acid (leucovorin; calcium folinate), typically > or = 50% in the first-line setting and 13 to 45% as a second-line therapy. First-line triple therapy with oxaliplatin and fuorouracil/folinic acid achieved significantly higher response rates and longer median progression-free survival than fluorouracil/folinic acid therapy alone. However, no significant difference in the median duration of overall survival was found. This may be a consequence of the subsequent use of oxaliplatin and/or surgery after disease progression in patients who relapsed after fluorouracil/folinic acid therapy alone. Neoadjuvant therapy with oxaliplatin/fluorouracil/folinic acid has proven beneficial in enabling surgical removal of previously unresectable liver metastases. In 2 studies, surgery with curative intent was performed in 16 and 51% of patients with initially unresectable liver metastases following oxaliplatin/fluorouracil/folinic acid therapy; the 5-year survival rates were 40 and 50%, respectively. In patients with advanced ovarian cancer, first-line therapy with oxaliplatin/cyclophosphamide achieved an objective response rate which did not differ significantly from that of cisplatin/cyclophosphamide (33 vs 42%). In addition, oxaliplatin has shown efficacy in patients with platinum-pretreated ovarian cancer and achieved objective response rates similar to paclitaxel in this setting (16 vs 17%). Promising results have also been found with oxaliplatin in patients with non-Hodgkin's lymphoma, breast cancer, mesothelioma and non-small cell lung cancer. Reversible, cumulative, peripheral sensory neuropathy is the principle dose-limiting factor of oxaliplatin therapy. Haematological and gastrointestinal toxicities occur frequently but are generally mild to moderate in intensity. ⋯ Oxaliplatin in combination with fluorouracil/folinic acid is an effective treatment option for patients with metastatic colorectal cancer, both as a first-line therapy and in patients refractory to previous chemotherapy. Although preliminary results failed to show any overall survival advantage of this regimen over fluorouracil/folinic acid alone, this may be a consequence of trial design and requires further examination. Additional clinical investigation of oxaliplatin in patients with other cancers is warranted given the promising results achieved in early trials, most notably in patients with platinum-pretreated ovarian cancer.
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Levetiracetam, the S-enantiomer of alpha-ethyl-2-oxo-1-pyrollidine acetamide, is approved for use as adjunctive therapy in adult patients with partial onset seizures. Oral levetiracetam 1000, 2000 and 3000 mg/day administered as adjunctive therapy for up to 18 weeks significantly increased responder rates and reduced seizure frequency compared with placebo in 3 well designed pivotal trials in adults with treatment-refractory partial seizures with or without secondary generalisation. Levetiracetam 3000 mg/day also significantly increased the number of seizure-free patients, but the effects of levetiracetam 1000 and 2000 mg/day on this end-point were unclear. Effects on seizure severity were not assessed in these trials. Although not yet approved as monotherapy or for use in paediatric patients, efficacy was observed with levetiracetam 3000 mg/day as monotherapy in adult patients with refractory partial seizures with or without secondary generalisation and with the 10 to 40 mg/kg/day dosage as adjunctive therapy in children with refractory partial seizures. However, these data are limited. Oral levetiracetam 1000, 2000 and 3000 mg/day as adjunctive therapy is generally well tolerated with an overall incidence of adverse events similar to that observed with placebo. The most commonly reported events in individual clinical trials were CNS-related and included somnolence, asthenia, headache and dizziness. Levetiracetam administered as adjunctive therapy does not appear to interact with other anticonvulsant drugs, and no clinically relevant interactions were observed between levetiracetam and digoxin, warfarin or probenecid; oral contraceptive protective efficacy was also not affected by levetiracetam. ⋯ Levetiracetam is a new anticonvulsant agent with a favourable tolerability profile and a low potential for drug interactions. It has shown efficacy as adjunctive therapy in patients with treatment-refractory partial onset seizures with or without secondary generalisation in clinical trials. Direct comparative trials with other anticonvulsant agents are not yet available, but placebo-controlled clinical evidence to date suggests that levetiracetam (1000, 2000 and 3000 mg/day) is a useful option as adjunctive therapy in patients with this subtype of epilepsy.