Aspirin Poisoning

Aspirin is a trade name for acetylsalicylic acid, a common pain reliever (also called an analgesic). The earliest known uses of the drug can be traced back to the Greek physician Hippocrates in the fifth century BC. He used powder extracted from the bark of willows to treat pain and reduce fever.

• Salicin, the parent of the salicylate drug family, was successfully isolated from willow bark in 1829. Sodium salicylate, a predecessor to aspirin, was developed, along with salicylic acid, as a pain reliever in 1875.

• Sodium salicylate was not often popular though, because it irritated the stomach. However, in 1897, Felix Hoffman changed the face of medicine forever. Hoffman was a German chemist working for Bayer. He had been using the common pain reliever of the time, sodium salicylate, to treat his father's arthritis. The sodium salicylate caused his father the same stomach trouble it caused other people, so Hoffman attempted to create a less acidic salicylate formula. His work led to the synthesis of acetylsalicylic acid, or ASA. This soon became the pain reliever of choice for doctors around the globe.

• In the 1970s, British pharmacologist John Vane, PhD, began studying how aspirin works to relieve pain and reduce fever. Vane and his colleagues found that aspirin inhibits the release of a hormonelike substance called prostaglandin. This chemical helps regulate blood vessel elasticity and changes the functioning of blood platelets. Thus aspirin can affect blood clotting and ease inflammation.

• Intentional and accidental
  
  
  • Intentional: For a variety of reasons, some people intentionally ingest poisons or poison others. Some reasons include the following:
    
    
    • To commit suicide
    
    
    
    • To gain personal attention
    
    
    
    • To commit child abuse
  
  
  • Accidental
    
    
    • Accidental poisonings usually affect children. From 1972-1976, there were 1-2 million cases of accidental poisoning per year in the United States. Since 1976, the number of accidental poisonings has dropped to about 500,000 cases per year. This decrease is attributed to the Poison Prevention Packaging Act and to poison prevention publicity.
    
    
    
    • The most common sources of accidental poisoning were plants, various types of cleaners (soaps, detergents, and household cleaners), vitamins and minerals, and aspirin. Aspirin is no longer the most common cause of accidental poisoning. This is probably because of child-resistant packaging.

• Inappropriate dosing in children and elderly people: Hundreds of medications available both over-the-counter and by prescription contain aspirin or aspirin-like substances. Unintentional aspirin poisoning can result if these medications are taken in combination, in inappropriate doses, or over a long time period. This is especially likely to occur in older people with chronic health problems.

The earliest symptoms of acute aspirin poisoning may include ringing in the ears (tinnitus) and impaired hearing. More clinically significant signs and symptoms include rapid breathing (hyperventilation), vomiting, dehydration, fever, double vision, and feeling faint.

Later signs of aspirin poisoning, or signs of more significant poisoning, include drowsiness or confusion, bizarre behavior, unsteady walking, and coma.

The abnormal breathing caused by aspirin poisoning is usually rapid and deep. Vomiting may occur 3-8 hours after taking too much aspirin. Serious dehydration may occur from hyperventilation, vomiting, and fever.

Aspirin poisoning signs and symptoms can range from minor to severe.

• Mild to moderate: Deep and rapid breathing (hyperpnea) sometimes with lethargy (abnormal drowsiness)

• Moderate: Severe deep and rapid breathing, prominent nervous system disturbances, such as marked lethargy or excitability, but no coma or convulsions

• Severe: Severe deep and rapid breathing, coma, sometimes with convulsions

If minor symptoms of aspirin overdose are experienced, call a doctor to see if the medication should be stopped or the dosage reduced. Minor symptoms include ringing in the ears, dry mouth, and dizziness.

For all other symptoms, call 911 (or the local emergency phone number) immediately. Also consider going directly to a hospital's emergency department for evaluation. Serious symptoms include the following:

• Agitation, fever, convulsions, collapse, confusion, coma



• Low blood pressure



• Rapid heart rate



• Rapid breathing



• Wheezing



• Nausea and vomiting



• Bleeding



• Hallucinations



• Drowsiness

Get emergency help immediately if any of the following symptoms occur with aspirin overdose:

• Any hearing loss



• Any abnormal bleeding



• Confusion



• Convulsions (seizures)



• Dizziness (severe)



• Drowsiness (severe)



• Excitement or nervousness (severe)



• Fast or deep breathing



• Hallucinations (seeing, hearing, or feeling things that are not there)



• Headache (severe or continuing)



• Increased sweating



• Nausea or vomiting (severe or continuing)



• Ringing or buzzing in the ears (continuing)



• Sweating



• Unexplained fever



• Unusual thirst



• Vision problems

The doctor will take a history and perform a physical examination to look for evidence of poisoning. The doctor will order laboratory tests to look for damage to organ systems that can be harmed by aspirin overdose and, depending on the timing, also to check for the level of aspirin in the bloodstream.

• The initial assessment of all poison victims follows the principles of basic and advanced cardiac life support. The doctor will make sure you are able to breathe and will check vital signs including body temperature. The doctor will check alertness by asking you to respond to questions. If you are unconscious, the doctor will give oxygen and perhaps use machines to help you breathe.

• Blood will be taken for lab testing. One blood test will measure the amount of salicylate, the active ingredient in aspirin, in your blood. Sometimes the blood level of salicylate can increase over time even though an individual has not taken any more aspirin. This may indicate the person has taken coated tablets or sustained-release tablets, which release salicylate into the bloodstream slowly.

• The doctor will make treatment decisions based on the dose of active ingredient ingested, the time over which it was ingested, your age, the symptoms you are experiencing, and your acid-base status. Acid-base status is the balance of acid and base in the blood. Aspirin may change this balance quickly, so the doctor will monitor this to guide treatment.

|Self-Care at Home|

If a drug overdose is discovered or suspected, and the victim is unconscious, having convulsions, not breathing, or is otherwise seriously ill, call 911 immediately (or the local emergency phone number) for medical help.

If the person who took the drug is not having symptoms, do not wait to see if symptoms develop. Call the local poison control center immediately. It is a good idea to post the telephone number of the local poison control center near the phone. This information can be found at: American Association of Poison Control Centers. Or call (800) 222-1222 if you have a poisoning emergency.

Providing as much information as possible to the poison control center can help determine what the next course of action should be.

• The poison control center, paramedics, and emergency department staff will want to know the following information:
  
  
  • What medications were taken? Try to locate the medication's container.
  
  
  
  • Precisely what is the medication that was taken; what is its name; how many milligrams (mg) is each pill?
  
  
  • How much of the medication was taken?
  
  
  • When was the medication taken?
  
  
  • Was the medication taken with alcohol or any other drugs or chemicals?
  
  
  • What is the victim's age?
  
  
  • What symptoms are present?
  
  
  • Is the person conscious?
  
  
  • Is the victim breathing?
  
  
  • What medical conditions does the victim have?

• Although ipecac syrup was used commonly in the past to make the victim vomit, it is rarely recommended today. It would not be suggested in aspirin poisoning due to the chance that the victim might develop altered mental status or convulsions.

|Medical Treatment|

• The treatment of aspirin poisoning has 3 objectives:
  
  
  • To prevent further absorption of aspirin into the body
  
  
  
  • To correct dehydration and acid-base abnormalities
  
  
  
  • To reduce the amount of salicylate within the body by increasing the rate at which the body can get rid of it


• Gastric lavage may be beneficial, unless contraindicated, up to 60 minutes after salicylate ingestion. Warmed (38°C) isotonic sodium chloride solution may be used. The airway should be protected before gastric lavage.



• Dialysis is another way to reduce the amount of salicylate in the body. The same technique that helps patients with kidney failure rid their bodies of toxins can also be used to quickly eliminate aspirin from the body of a person who has been poisoned with aspirin.

|Medications|

Activated charcoal: To prevent more absorption, the doctor may give activated charcoal to absorb the salicylate from the stomach. A laxative may be given with the activated charcoal to move the mixture through the gastrointestinal system more rapidly. People who have been severely poisoned may be given repeated doses of activated charcoal.

IV fluids: Dehydration occurs early in aspirin poisoning. To correct dehydration, the doctor will start an IV to correct this imbalance. The doctor will also work to correct imbalances in the body's blood chemistries.

Alkaline diuresis: This is a way to reduce the amount of salicylate in the body. Alkaline diuresis is the process of giving a person who has been poisoned compounds that alter the chemistry of the blood and urine in a way that allows the kidneys to remove more salicylate. Specifically, sodium bicarbonate is given via IV to make the blood and urine less acidic (more alkaline), which encourages the kidneys to capture more salicylate that can leave the body through the urine. Sometimes, other compounds, such as potassium, also have to be given to help with this process.

|Other Therapy|

• The emergency physician may have to perform other procedures or give other medications as supportive care in the case of dangerous aspirin overdose. These actions may include the following: 
  
  
  • Placing a breathing tube (intubation) and assisting breathing with a ventilator for a person who is agitated, in a coma, who cannot protect their own airway, or for whom mechanical breathing could be helpful
  
  
  • Placement of a catheter into the bladder to monitor urine output and frequently check the acidity (pH) of the urine
  
  
  • Administration of other medications as may be needed to treat agitation, convulsions (seizures), or other complications of aspirin poisoning

• Admit patients with major signs and symptoms (for example, neurological, cardiopulmonary, and metabolic) to an intensive care unit under the care of a medical toxicologist, if available. Consult psychiatric service personnel for patients with intentional overdose.


• Admit patients with minor signs and symptoms (for example, tinnitus and nausea) to an extended care observational unit or medical floor.


• Admit the following patients, regardless of salicylate levels:
  
  
  • Infants and elderly persons
  
  
  • Individuals with long-term salicylism
  
  
  • Those with ingestions of sustained-release products

|Follow-up|

People with acute, single ingestions of non—enteric-coated aspirin of less than 150 mg/kg who have no symptoms and have a nontoxic aspirin level after 6 hours may be released from the hospital. All others with aspirin poisonings will likely be treated in the emergency department, then hospitalized for further treatment and observation.

• Psychiatric and medical follow-up may be recommended.


• Careful monitoring of medication intake will be recommended as well.


• Tests to monitor kidney function may be done periodically after hospital discharge, especially in elderly people.

|Prevention|

Prescription medications should be used according to your doctor's and pharmacist's directions.

• Never take a medicine prescribed for someone else.
  
  
• To protect children from accidental drug overdose, all medications should be stored in containers with child-resistant caps. All medications should be out of sight and out of reach of children, preferably in a locked cabinet.
  
  
• Take suicidal threats seriously.
  
  
• Never give or take medication in the dark.
  
  
• Always tell the doctor of any previous side effects or adverse reactions to medication as well as any new or unusual symptoms that occur.
  
  
• Never take more than the recommended or prescribed dose of a medication.
  
  
• Inform your doctor about all the medications you are taking. Be sure to mention over-the-counter medications.

|Outlook|

Recovery is likely if the proper treatment is given and the dose of aspirin taken is not too high.

Signs and symptoms as well as prognosis in chronic aspirin poisoning are less predictable. In the case of acute aspirin poisoning, symptom severity can be predicted by the dose ingested.

• Less than 150 milligrams of aspirin per kilogram of body weight (mg/kg) - no symptoms to mild toxicity
  
  
• Ingestions of 150-300 mg/kg - mild to moderate toxicity
  
  
• Ingestions of 300-500 mg/kg - serious toxicity
  
  
• Greater than 500 mg/kg - potentially lethal

|Web Links|

American Association of Poison Control Centers

AllRefer.com Health, Poisoning and Overdoses, Aspirin Overdose

MedlinePlus, Aspirin overdose

aspirin poisoning, aspirin overdose, aspirin toxicity, salicylate poisoning, ASA, analgesic, acetylsalicylic acid, poisoning, drug overdose, medication overdose, signs of aspirin poisoning, signs of aspirin overdose

Author: Hanan Al Hammadi, MD, Resident, Department of Family Medicine, Jewish General Hospital, Montreal, Canada.

Coauthor(s): Salih Ali Al-Marri, MD, FRFPC, Chair and Program Director, Department of Family and Community Medicine, Hamad General Hospital, Doha-Qatar.

Editors: Michael D Burg, MD, Assistant Clinical Professor, Department of Emergency Medicine, University Medical Center, University of California at San Francisco-Fresno; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, ; Richard Harrigan, MD, Associate Professor, Department of Emergency Medicine, Temple University Hospital, Temple University School of Medicine.