Acetylsalicylic Acid

Defining Acetylsalicylic Acid

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Medical Specialties:

Cardiology, Family practice, Internal medicine

Clinical Definition:

Acetylsalicylic acid, also known as aspirin, is classified as a non-steroidal anti-inflammatory (NSAID) pharmaceutical agent. It contains salicylic acid, the active metabolite that inhibits prostaglandins. Of note, prostaglandins are hormone-like fatty acids that perform many physiologic actions, such as the influence of pain signals, contraction of smooth muscle or control of blood pressure.

Acetylsalicylic acid is used as an antipyretic and analgesic.  Antipyretics are substances that fight fever. Aspirin is also sometimes prescribed as an antiplatelet agent in to reduce the risk of a myocardial infarction (heart attack) and cerebrovascular accident (stroke).

In Our Own Words:

Acetylsalicylic acid—typically referred to as aspirin—is a common over-the-counter medication used to treat inflammation, pain, and fever. This drug works by decreasing the effects of prostaglandins (i.e., chemicals in the body that influence pain signals).

Aspirin also thins the blood, and​, for this reason, low-dose aspirin is sometimes used to help prevent heart attack or stroke in certain high-risk patients.

Adverse Effects of Acetylsalicylic Acid and Salicylates

Although aspirin is readily available in various over-the-counter preparations, and many people take this medication without much consideration, if these substances are taken in excess or chronically, toxicity and even death can occur.

For instance in 2008, the American Association of Poison Control Centers National Poison Data System reported 20,000 exposures to aspirin and salicylic acid, or salicylates, as well as 48 associated deaths.

Of particular concern among clinicians and public health experts is the sheer number of products that contain salicylate and the unwitting abuse of these substances by both adults and children.

For example, liniments like BENGAY or hot vaporizers contain methyl salicylate, and if used in excess, these preparations can do serious harm.

The toxic effects of salicylism (aspirin or salicylate poisoning) depend on the age of the person, the amount ingested and the duration of the exposure. The clinical symptoms of salicylism fall into 3 categories: mild, moderate and severe.

Here are the symptoms of mild salicylate toxicity:

  • hearing loss
  • tinnitus (ringing in the ears)
  • nausea
  • vomiting

Here are the symptoms of moderate salicylate toxicity:

  • anxiety
  • excess sweating
  • high fever
  • anxiety
  • ataxia (lost control of bodily movements)

Here are the symptoms of severe salicylate toxicity:

No specific antidote for salicylate toxicity exists. Instead, patients are immediately resuscitated and stabilized (airway, breathing and circulation). Subsequently, metabolic, or body-salt, derangements, and volume depletion are corrected. Furthermore with severe toxicity, clinicians work to reduce the amount of salicylates in a patient's system by gastric lavage (stomach pumping) and administration of charcoal.

Activated charcoal is administered by mouth and works by absorbing or sucking up aspirin salicylates on its way out the gastrointestnal tract.


The Children’s Hospital of Philadelphia. “Aspirin: The Basics.” Accessed February 2014.

University of Washington Department of Orthopaedics and Sports Medicine. “Aspirin and Related Drugs." Accessed February 2014.

UC Davis Health System. “Who should consider taking a daily aspirin?” Accessed February 2014.

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