Concomitant use of buffered and enteric-coated low-dose aspirin products and antisecretory drugs.
OBJECTIVE
Buffered and enteric-coated formulations of low-dose aspirin therapy are although expected to avoid gastrointestinal complications, there are reports that these modified products are associated with such complications. One available option for preventing aspirin-induced gastrointestinal complications is the simultaneous use of the agents that inhibit acid secretion such as H(2)-receptor antagonists and proton pump inhibitors. We compared the frequency of prescriptions for antisecretory drugs between users of either buffered or enteric-coated low-dose aspirin.


METHODS
Monthly prescriptions at the National Cardiovascular Center for aspirin products and antisecretory drugs were counted from January 1998 to December 2002. Counting was based on information from a prescription database file compiled from a computerized order entry system. Time-series analyses were performed to determine changes in the frequency of prescriptions for low-dose aspirin products and antisecretory drugs. In addition, the frequency of prescriptions for antisecretory drugs was compared in individuals using either buffered or enteric-coated low-dose aspirin.


RESULTS
A significant reduction in the frequency of prescriptions for H(2)-receptor antagonists was observed during 2001 in users of enteric-coated low-dose aspirin compared with users of buffered low-dose aspirin users. In contrast, we observed a significant increase in the frequency of prescriptions for H(2)-receptor antagonists in users of enteric-coated low-dose aspirin during 2002. This change in prescribing H(2)-receptor antagonists in users of enteric-coated low-dose aspirin began in the latter half of 2001. Proton pump inhibitors accounted for 0.31% of prescriptions in users of buffered low-dose aspirin and 0.47% in users of enteric-coated low-dose aspirin, with this difference being statistically significant.


CONCLUSIONS
The findings of the present study do not support the notion that enteric-coated low-dose aspirin reduces the risk of gastrointestinal complications and is safer than buffered low-dose aspirin products. However the usual caution about making inferences from observational retrospective data is appropriate.
Takada
M
M
Department of Pharmacy, National Cardiovascular Center, Osaka, Japan. takada@hsp.ncvc.go.jp
Fukumoto
K
K
Shibakawa
M
M
D000284:Administration, Oral; D001241:Aspirin / Q000008:administration & dosage / Q000009:adverse effects*; D002318:Cardiovascular Diseases / Q000517:prevention & control; D016208:Databases, Factual; D011307:Drug Prescriptions / Q000706:statistics & numerical data; D006471:Gastrointestinal Hemorrhage / Q000139:chemically induced* / Q000453:epidemiology; D006635:Histamine H2 Antagonists / Q000008:administration & dosage*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects*; D013608:Tablets, Enteric-Coated / Q000008:administration & dosage / Q000009:adverse effects
D006635:Histamine H2 Antagonists; D010975:Platelet Aggregation Inhibitors; D013608:Tablets, Enteric-Coated; D001241:Aspirin