The available evidence , predominantly from secondary -prevention observational studies , supports that dosages greater than 75 to 81 mg/d do not enhance efficacy , whereas larger dosages are associated with an increased incidence of bleeding events , primarily related to gastrointestinal tract toxicity .
CONCLUSIONS Currently available clinical data do not support the routine , long-term use of aspirin dosages greater than 75 to 81 mg/d in the setting of cardiovascular disease prevention .
Higher dosages , which may be commonly prescribed , do not better prevent events but are associated with increased risks of gastrointestinal bleeding
CONTEXT More than 50 million US adults take aspirin regularly for long-term prevention of cardiovascular disease , typically either 81 mg/d or 325 mg/d .
Controversy remains regarding the most appropriate long-term daily dose .
OBJECTIVE To review the mechanism of action of aspirin and the clinical literature for relationships among  aspirin dosage , efficacy , and safety .
EVIDENCE SYNTHESIS Although pharmacodynamic data demonstrate that long-term aspirin dosages as low as 30 mg/d are adequate to fully inhibit platelet thromboxane production , dosages as high as 1300 mg/d are approved for use .
Adverse drug reactions as cause of admission to hospital: prospective analysis of 18 820 patients
Abstract Objective To ascertain the current burden of adverse drug reactions ( ADRs ) through a prospect i ve analysis of all admissions to hospital . Design Prospect i ve observational study . Setting Two large general hospitals in Merseyside , Engl and . Participants 18 820 patients aged > 16 years admitted over six months and assessed for cause of admission . Main outcome measures Prevalence of admissions due to an ADR , length of stay , avoidability , and outcome . Results There were 1225 admissions related to an ADR , giving a prevalence of 6.5 % , with the ADR directly leading to the admission in 80 % of cases . The median bed stay was eight days , accounting for 4 % of the hospital bed capacity . The projected annual cost of such admissions to the NHS is £ 466 m ( € 706 m , $ 847 m ) . The overall fatality was 0.15 % . Most reactions were either definitely or possibly avoidable . Drugs most commonly implicated in causing these admissions included low dose aspirin , diuretics , warfarin , and non-steroidal anti-inflammatory drugs other than aspirin , the most common reaction being gastrointestinal bleeding . Conclusion The burden of ADRs on the NHS is high , accounting for considerable morbidity , mortality , and extra costs . Although many of the implicated drugs have proved benefit , measures need to be put into place to reduce the burden of ADRs and thereby further improve the benefit : harm ratio of the drugs
The available evidence , predominantly from secondary -prevention observational studies , supports that dosages greater than 75 to 81 mg/d do not enhance efficacy , whereas larger dosages are associated with an increased incidence of bleeding events , primarily related to gastrointestinal tract toxicity .
CONCLUSIONS Currently available clinical data do not support the routine , long-term use of aspirin dosages greater than 75 to 81 mg/d in the setting of cardiovascular disease prevention .
Higher dosages , which may be commonly prescribed , do not better prevent events but are associated with increased risks of gastrointestinal bleeding
CONTEXT More than 50 million US adults take aspirin regularly for long-term prevention of cardiovascular disease , typically either 81 mg/d or 325 mg/d .
Controversy remains regarding the most appropriate long-term daily dose .
OBJECTIVE To review the mechanism of action of aspirin and the clinical literature for relationships among  aspirin dosage , efficacy , and safety .
EVIDENCE SYNTHESIS Although pharmacodynamic data demonstrate that long-term aspirin dosages as low as 30 mg/d are adequate to fully inhibit platelet thromboxane production , dosages as high as 1300 mg/d are approved for use .