ABSTRACT
PURPOSE: To estimate the incidence of pancytopenia in patients taking leflunomide with or without methotrexate in Australia. METHODS: Review of spontaneous reports to the Australian Adverse Drug Reactions Advisory Committee (ADRAC); estimation of incidence using national prescription reimbursement data; concomitant exposure to methotrexate was estimated using three sources of information. RESULTS: ADRAC received 11 reports of pancytopenia (meeting predefined criteria) associated with the use of leflunomide during its first 31 months of marketing. In nine reports, the patients were also taking methotrexate. Estimates of incidence in patients taking leflunomide alone ranged from 1 in 3698 to 1 in 4582 patients exposed; for patients also taking methotrexate the estimates ranged from 1 in 575 to 1 in 822. CONCLUSIONS: Use of methotrexate with leflunomide increases the risk of pancytopenia compared with use of leflunomide alone. The haematological toxicity of the combination requires further study.
Subject(s)
Adverse Drug Reaction Reporting Systems/statistics & numerical data , Isoxazoles/adverse effects , Methotrexate/adverse effects , Pancytopenia/epidemiology , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Anemia/chemically induced , Anemia/epidemiology , Antirheumatic Agents/adverse effects , Antirheumatic Agents/therapeutic use , Australia/epidemiology , Carbamazepine/adverse effects , Carbamazepine/therapeutic use , Child , Drug Prescriptions/statistics & numerical data , Drug Therapy, Combination , Drug Utilization Review/methods , Drug Utilization Review/statistics & numerical data , Female , Humans , Incidence , Isoxazoles/metabolism , Isoxazoles/therapeutic use , Leflunomide , Male , Methotrexate/therapeutic use , Middle Aged , Neutropenia/chemically induced , Neutropenia/epidemiology , Organogold Compounds/administration & dosage , Organogold Compounds/adverse effects , Pancytopenia/chemically induced , Thrombocytopenia/chemically induced , Thrombocytopenia/epidemiologyABSTRACT
AIM: To estimate the percentage of patients dispensed alendronate who were also dispensed another drug for treatment of an upper gastrointestinal disorder ('GI' drug). METHODS: The Australian Health Insurance Commission (HIC) Pharmaceutical Benefits Scheme (PBS) database was searched to identify a cohort of patients for whom alendronate or calcitriol had been dispensed and had also been dispensed a GI drug. RESULTS: The number of patients dispensed a GI drug were 6.7% for alendronate and 7.5% for calcitriol with H(2)-receptor antagonists accounting for the majority of usage. This difference of - 0.8% (95% confidence interval -1.6, 0.1) is not significant. CONCLUSION: There was no excess use of GI drugs in patients taking alendronate compared with those taking calcitriol and the Australian HIC PBS database is useful for identifying large numbers of patients who have been dispensed combinations of drugs.
