Aspirin
David J. George in Poisons, 2017
Aspirin is the common name for acetylsalicylic acid. Derivatives of salicylic acid are collectively referred to as salicylates. Although aspirin is the most familiar salicylate, there are other forms of salicylate utilized in clinical medicine. Toxic exposures most often result from either adult suicidal ingestion, excessive utilization of salicylate products in therapeutic situations, or pediatric accidental ingestions. The majority of pediatric aspirin deaths result from administration of excessive amounts by parents or other caregivers for therapeutic reasons. In 2009, a 53-year-old man living in Philadelphia went to a hospital emergency department about an hour after ingesting about 200 adult aspirin tablets in a suicide attempt. Aspirin could also cause pylorospasm that would delay transfer from the stomach to the intestine. Characteristics of the particular aspirin formulation such as coatings and tableting materials that might be unimportant in therapeutic dosing can become a critical consideration in poisoning cases in which exposures might involve huge numbers of dosage units.
A Randomised, Blinded, Trial of Clopidogrel versus Aspirin in Patients at Risk of Ischaemic Events (CAPRIE)
Samuel Eric Wilson in 50 Landmark Papers Every Vascular and Endovascular Surgeon Should Know, 2020
Antiplatelet therapy's role in reducing cardiovascular risk has been long established, first by the Antiplatelet Trialists’ Collaboration meta-analysis study in 1994 and expounded upon by the Antithrombotic Trialists’ Collaboration group's 2002 systemic review, both showing an approximately 20% odds reduction in vascular events in patients on antiplatelet therapy compared to controls. However, prior to clopidogrel, no safe alternative to aspirin had been approved for the prevention of cardiovascular morbidity. Previously, ticlopidine, an alternate thienopyridine derivative to clopidogrel, had shown a significant decrease in the risk of adverse cardiovascular events compared to placebo but with an unfavorable side effect profile. CAPRIE marked clopidogrel's coronation as a safe and efficacious antiplatelet agent that has since expanded its role in a growing environment of endovascular neurologic, cardiac, visceral, and peripheral interventions. As both an aspirin alternative and part of dual antiplatelet therapy, clopidogrel is already a mainstay of vascular medicine and as essential as surgical intervention.
Practice Paper 3: Questions
Benjamin McNeillis, Rhian James, Ai Ling Koh, Tim Sparkes in Get ahead! Medicine: 300 SBAs for Finals, 2011
A 55-year-old man has presented to the medical admissions unit with chest pain. You have diagnosed acute coronary syndrome (ACS) and are about to write up his drug chart. Your most suitable prescription would be: A 75 mg aspirin, clopidogrel, treatment dose heparin stat with glyceryl trinitrite (GTN) spray and morphine PRN B 75 mg aspirin, clopidogrel, treatment dose heparin and beta-blocker stat with GTN spray and morphine PRN C 300 mg aspirin, clopidogrel, prophylactic dose heparin stat with GTN spray and morphine PRN D 300 mg aspirin, clopidogrel, treatment dose heparin and beta-blocker stat with GTN spray and morphine PRN E 300 mg aspirin, prophylactic heparin and beta-blocker stat with GTN spray and morphine PRN 2. Haematuria A 32-year-old man presents to the GP 4 days after an episode of painless haematuria, 2 weeks following a sore throat. He says he now feels he is producing less urine than usual and that it is brown. He denies any weight loss or fatigue, and has no family history of urological malignancy. On examination, he has a blood pressure of 155/90 mmHg, +++ blood on urine dipstick, and blood tests reveal a creatinine of 170 µmol/L and normal electrolytes.
The Influence of Dosage Form on Aspirin Kinetics: Implications for Acute Cardiovascular Use
Published in Current Medical Research and Opinion, 1997
N. Muir, J. D. Nichols, J. M. Clifford, M. R. Stillings, R. C. Hoare
Summary In this study, the pharmacokinetics of several formulations of aspirin were examined: soluble aspirin, mouth-dispersible aspirin, plain aspirin and enteric-coated aspirin granules. Blood samples were taken at frequent intervals for 24 hours after single dosing in 12 healthy volunteers and Tmax, Cmax and t1/2 measured. Cmax was significantly higher for soluble aspirin than for the other formulations and the t1/2was shorter. The results show the rapid absorption of aspirin from a soluble formulation compared with that from plain aspirin or enteric-coated aspirin granules. Recommendations to treat patients suspected of having a heart attack as soon as possible with aspirin are now widely accepted and the present study would suggest that soluble aspirin should be the aspirin of choice in this situation.
Decreased turnover aspirin resistance by bidaily aspirin intake and efficient cytoreduction in myeloproliferative neoplasms
Published in Platelets, 2018
Andréas Perrier-Cornet, Jean-Christophe Ianotto, Fanny Mingant, Maëla Perrot, Eric Lippert, Hubert Galinat
Essential thrombocythemia (ET) and polycythemia vera (PV) are myeloproliferative neoplasms (MPN) with an increased risk of arterial and venous thrombosis. Aspirin is recommended to reduce this risk, but resistance to antiplatelet therapy seems to hamper its efficacy in some patients. We have previously shown that multiple electrode aggregometry (MEA) was a valuable tool to assess aspirin resistance in MPN. In this study, MEA was used to assess the reduction in aspirin resistance after bi-daily (BID) aspirin intake or cytoreduction. Fifty one MPN patients (31 ET and 20 PV) receiving 75 mg aspirin once daily (OD) or BID, with or without cytoreductive treatment, were analyzed. Aspirin resistance was assessed using whole blood MEA (Multiplate®, Roche Diagnostics, Meylan, France). In all patients, global aspirin resistance consisted mainly of turnover resistance (TOR). 94% of patients with OD aspirin intake and without cytoreduction displayed biological aspirin resistance. By switching to a BID aspirin regimen, the proportion of resistant patients reduced to 47%. Cytoreduction also contributed to reduce aspirin resistance in a similar way (50% of aspirin resistant patients). Combining cytoreduction and BID aspirin regimen was the most efficient way to reduce aspirin resistance yielding to 12% resistant patients. Moreover, a nonlinear correlation was observed between TOR and naive platelet counts regardless of aspirin regimen. Last, mutational status did not seem to affect TOR. This study confirmed that BID aspirin is biologically more effective than OD aspirin in reduction of aspirin resistance. The latter was achieved through a reduction in TOR which was also decreased by cytoreductive therapy.
The Effect of Different Antithrombotic Regimens on Platelet Aggregation After Myocardial Infarction
Published in Scandinavian Cardiovascular Journal, 1998
Mette Hurlen, Ingebjørg Seljeflot, Harald Arnesen
Platelet aggregate ratio (PAR) was measured according to the method of Wu & Hoak in 143 patients after acute myocardial infarction (AMI) and in 54 controls. A PAR < 1 expresses the presence of platelet aggregates. The patients were randomized to aspirin 160 mg/d, or warfarin, or aspirin 75 mg/d + warfarin. In patients on aspirin, PAR was measured 24 h after aspirin intake, and in 76 patients also 2 h after aspirin. The median PAR in patients on warfarin was 0.85, on warfarin + aspirin 0.91 and on aspirin alone 0.94, all significantly lower than the median PAR of 0.97 in the controls. In 14 patients on aspirin the PARs were below a cut-off point of 0.82 (secondary aspirin non-responders). PAR increased significantly 2 h after aspirin intake. In two patients, however, PAR remained low (primary aspirin non-responders). It is concluded that some patients do not seem to respond to aspirin, the clinical implication of which has yet to be determined.
Related Knowledge Centers
- Salicylic Acid
- Analgesic
- Anti-Inflammatory
- Antipyretic
- Pharmaceutical Drug