Over-the-Counter Overdoses

Effects, symptoms and treatments for toxic overdoses of over-the-counter drugs


      We were called at 2 a.m. to a university apartment for a 21-year-old female who had overdosed. We arrived on scene to find a very distraught woman. After a fight with her boyfriend earlier in the evening, she had swallowed several handfuls of ibuprofen.

   She insisted she was fine now, that she didn't take that many and that it was "just ibuprofen," and she had no interest in going to the hospital. However, when I assessed the young woman, her vitals were elevated, and she was slightly diaphoretic. Was she just worked up from her fight, or was there something medically wrong? Was she right that ibuprofen wouldn't hurt her? Could we safely sign her off?

   Over-the-counter (OTC) drug abuse is on the rise. Since 2000 there has been a fourfold increase in abuse of cold medicine. Nonsteroidal anti-inflammatory drugs (NSAIDS) are the third most commonly intentionally overdosed medicine. Acetaminophen overdose is responsible for the greatest number of drug overdose hospital admissions in developed countries. Hundreds of different nonprescription medicines are available. This article discusses assessment and treatment considerations for overdoses of four of the most commonly abused OTC drugs.

RISK FACTORS

   Nonprescription medications are easy to obtain. Thus, they are appealing to youth: Adolescents are the most common over-the-counter drug abusers, and they often combine OTC drugs with street drugs and alcohol. Teen OTC drug abuse often occurs in fads, as groups of teens discover the effects of the drugs together.

   Not all overdoses are intentional. Some are accidental, and many patients are at risk of greater adverse effects from regular doses of OTC drugs. For example, alcohol consumption creates a synergistic effect with many medications, especially NSAIDs. Patients over 60 additionally risk gastrointestinal bleeding from even regular doses of NSAIDs. GI bleeding can also develop from NSAID overdose when a patient is on blood thinners or has a history of ulcers.

   As with many medical problems, the very young and very old suffer the worst consequences. Nearly half (46%) of all antihistamine overdoses involve children under 6.

CASE #1: SEVERE PAIN

   A nervous mother calls you for her son, who recently broke his leg. Your 16-year-old patient is lying on the couch, complaining of severe right upper quadrant pain that has been worsening for the past two days. His mother tells you he has been vomiting frequently for "a while." A physical exam reveals abdominal tenderness and no signs of problems with the broken leg. The patient's heart rate is 112, blood pressure 94/60 and respiratory rate 28. The boy tells you he has been taking acetaminophen for his leg pain. A bottle of 500-mg pills on the coffee table is nearly empty. Based upon your exam and history findings, you suspect an accidental acetaminophen overdose.

   Acetaminophen is a non-narcotic pain medication used by millions of people each year. It is the most common adult analgesic and most common pediatric medication. Adults can safely ingest up to 4 grams of acetaminophen a day; pediatrics can ingest 90 mg/kg. Consumption of 150 mg/kg per day or more is toxic and considered an overdose. Acetaminophen overdose is the leading cause of acute liver failure in the U.S.

   After ingestion, acetaminophen is quickly absorbed through the stomach directly into the bloodstream. Once there it can only be metabolized into waste by the liver. The kidneys can only excrete acetaminophen after it is metabolized in the liver. Acetaminophen overdose saturates the liver's normal metabolic pathways and prevents effective function. As a result, a toxic metabolite forms, which binds with proteins in the liver, resulting in cellular death, which eventually leads to liver necrosis.

   Patients with acetaminophen toxicity go through four phases. Phase 1 occurs during the first 24 hours following ingestion. During this time the patient may be asymptomatic, but may also have loss of appetite, malaise, diaphoresis, pallor and complain of nausea and vomiting.

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