Acetylsalicylic Acid

Patients with sensitivity to tartrazine dyes, nasal polyps, and asthma may have an increased risk of salicylate sensitivity.

Discontinue use if tinnitus or impaired hearing occurs.

Low-dose aspirin for cardioprotective effects is associated with a two- to fourfold increase in UGI events. The risks of these events increase with increasing aspirin dose; during the chronic phase of aspirin dosing, doses >81 mg are not recommended unless indicated (Bhatt 2008). Disease-related concerns:

Use with caution in patients with platelet and bleeding disorders.

Use with caution in patients with dehydration.

Heavy ethanol use (>3 drinks/day) can increase bleeding risks and may enhance gastric mucosal damage.

Use with caution in patients with erosive gastritis. Avoid use in patients with active peptic ulcer disease.

Avoid use in severe hepatic failure.

When using high dosages (eg, analgesic or anti-inflammatory uses), use with caution and monitor renal function or consider the use of an alternative analgesic/anti-inflammatory agent (NKF [Henrich 1996]; Whelton 2000). Low-dose aspirin (eg, 75 to 162 mg daily) may be safely used in patients with any degree of renal impairment (KDOQI 2005; KDOQI 2007). Concurrent drug therapy issues:

In the treatment of acute ischemic stroke, avoid aspirin for 24 hours following administration of alteplase; administration within 24 hours increases the risk of hemorrhagic transformation (Jauch 2013).

When used concomitantly with ≤325 mg of aspirin, NSAIDs (including selective COX-2 inhibitors) substantially increase the risk of gastrointestinal complications (eg, ulcer); concomitant gastroprotective therapy (eg, proton pump inhibitors) is recommended (Bhatt 2008).

Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information. Special populations:

An individualized and multidisciplinary approach should be used to manage patients with an acute lower GI bleed (LGIB) who are on antiplatelet medications. Aspirin for primary prevention of cardiovascular events should be avoided in most patients with LGIB who do not have established cardiovascular disease and do not have high risk factors for cardiovascular events. However, aspirin for secondary cardiovascular prevention should generally not be discontinued in patients with established cardiovascular disease and a history of lower GI bleeding (Strate 2016).

When used for self-medication (OTC labeling): Children and teenagers who have or are recovering from chickenpox or flu-like symptoms should not use this product. Changes in behavior (along with nausea and vomiting) may be an early sign of Reye syndrome; patients should be instructed to contact their healthcare provider if these occur.

Aspirin should be avoided (if possible) in surgical patients for 1 to 2 weeks prior to elective surgery, to reduce the risk of excessive bleeding. In patients with cardiac stents or who have recently (within the previous 14 days) undergone balloon angioplasty that have not completed their full course of antiplatelet therapy (eg, dual antiplatelet therapy), antiplatelet therapy should be continued and elective surgery should be delayed until course of antiplatelet therapy is complete; patient specific situations should be discussed with cardiologist (ACC/AHA [Fleisher 2014]; ACC/AHA [Levine 2016]; AHA/ACC/SCAI/ACS/ADA [Grines 2007]). Dosage form specific issues:

Some dosage forms may contain polysorbate 80 (also known as Tweens). Hypersensitivity reactions, usually a delayed reaction, have been reported following exposure to pharmaceutical products containing polysorbate 80 in certain individuals (Isaksson 2002; Lucente 2000; Shelley 1995). Thrombocytopenia, ascites, pulmonary deterioration, and renal and hepatic failure have been reported in premature neonates after receiving parenteral products containing polysorbate 80 (Alade 1986; CDC 1984). See manufacturer's labeling. Other warnings/precautions:

Aspirin resistance is defined as measurable, persistent platelet activation that occurs in patients prescribed a therapeutic dose of aspirin. Clinical aspirin resistance, the recurrence of some vascular event despite a regular therapeutic dose of aspirin, is considered aspirin treatment failure. Proposed mechanisms of aspirin resistance include poor adherence with therapy, poor absorption, inadequate dosage, drug interactions, increased isoprostane activity, platelet hypersensitivity to agonists, increased COX-2 activity, COX-1 polymorphism, and platelet alloantigen 2 polymorphism of platelet glycoprotein IIIa. Estimates of biochemical aspirin resistance range from 5.5% to 60% depending on the population studied and the assays used (Gasparyan 2008). Patients with aspirin resistance may have a higher risk of cardiovascular events compared to those who are aspirin sensitive (Gum 2003). Aspirin resistance is likely dose-related but may be influenced by dynamic factors yet to be identified; further research is required.