Initiation of acetylcholinesterase inhibitors and complications of chronic airways disorders in elderly patients.
OBJECTIVE
Acetylcholinesterase inhibitors (AChEIs), commonly prescribed in Alzheimer's disease, may trigger complications of chronic airways disorders. The aim of this study was to determine whether initiation of therapy with AChEIs contributes to complications of chronic airways disorders in an elderly population.


METHODS
Sequence-symmetry analysis was used to assess two cohorts of patients, both with a history of chronic airways disorders. Both cohorts comprised Medicare beneficiaries who received drug coverage through the Pennsylvania Pharmaceutical Assistance Contract for the Elderly, between 1997 and 2002. One cohort of 922 patients initiated treatment with an AChEI; the other cohort of 2819 patients initiated treatment with a beta-adrenoceptor antagonist (beta-blocker), a comparator drug also contraindicated in chronic airways disorders. The occurrence of the following four outcomes in claims data was assessed: (i) emergency room visits for complications of chronic airways disorders; (ii) hospitalisations for complications of chronic airways disorders; (iii) physician visits for complications of chronic airways disorders; and (iv) dispensing of an antibacterial and an oral corticosteroid on the same day. Rate ratios (RRs) were adjusted for age, sex, race, nursing home residence, cognitive status, severity of chronic airways disorders, comorbid illnesses and all other patient characteristics that can be assumed to remain constant over the study period.


RESULTS
Initiators of AChEIs had no detectable increased rate of complications of chronic airways disorders. Adjusted RRs of the four outcomes ranged from 1.00 (95% CI 0.61, 1.62; p = 0.99) for physician visits to 1.64 (95% CI 0.55, 4.89; p = 0.37) for emergency room visits, none reaching statistical significance. In contrast, beta-blocker initiators had significantly increased rates of all four outcomes after treatment, with adjusted RRs ranging from 1.97 (95% CI 1.18, 3.29; p = 0.009) for emergency room visits to 2.76 (95% CI 1.71, 4.45; p < 0.0001) for dispensing of an antibacterial and oral corticosteroid on the same day.


CONCLUSIONS
These results suggest that, in current clinical practice, physicians can prescribe AChEIs safely to elderly patients with chronic airways disorders, while beta-blocker prescribing continues to result in adverse health outcomes.
Thacker
Evan L
EL
Division of Pharmacoepidemiology and Pharmacoeconomics, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts, USA. ethacker@hsph.harvard.edu
Schneeweiss
Sebastian
S
D000368:Aged; D000369:Aged, 80 and over; D002800:Cholinesterase Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D002908:Chronic Disease; D018592:Cross-Over Studies; D000077265:Donepezil; D005260:Female; D005702:Galantamine / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D007189:Indans / Q000009:adverse effects* / Q000627:therapeutic use; D016015:Logistic Models; D008297:Male; D048448:Phenylcarbamates / Q000009:adverse effects* / Q000627:therapeutic use; D010880:Piperidines / Q000009:adverse effects* / Q000627:therapeutic use; D012140:Respiratory Tract Diseases / Q000139:chemically induced*; D000068836:Rivastigmine
D002800:Cholinesterase Inhibitors; D007189:Indans; D048448:Phenylcarbamates; D010880:Piperidines; D005702:Galantamine; D000077265:Donepezil; D000068836:Rivastigmine