Many Patients Unaware of Risks and Proper Dosing for Acetaminophen

May 10, 2011

Studies show many patients have little knowledge about proper dosing and side effects associated with common OTC pain relievers.

A recently released study showing that many patients are not aware of the type or quantity of active ingredient in their over-the-counter (OTC) pain medications has resulted in increased scrutiny on medication safety issues and the proper use of OTC pain relievers, especially NSAIDs and drugs containing acetaminophen.

A study by Wolf et al. recently published in the American Journal of Preventive Medicine found wide variation in consumers’ knowledge of the active ingredients found in common OTC pain relievers. In the study, only 31% of participants correctly identified acetaminophen as the active ingredient in Tylenol; less than one-fifth (19%) of participants identified ibuprofen as the active ingredient found in Advil. In fact, the researchers reported that “Overall, participants demonstrated limited knowledge of the concept of ‘active ingredient.’” In general, the study participants reported that they “paid attention to the active ingredient in the medicine only if they knew of a contraindication for one of their other medicines, and relatively few participants mentioned this as a factor.” This is an important safety issue for pain management specialists and other physicians, especially in light of the general lack of awareness of the risks and side effects associated with OTC pain medications revealed by the study—for example, the authors reported that “Most participants, even those who had heard of acetaminophen, generally expressed surprise in learning that acetaminophen, or what they knew as Tylenol, can cause liver damage.”

Several pain advocacy and other professional organizations have recently taken up the banner of acetaminophen safety by launching awareness campaigns, releasing position statements, and providing a variety of additional tools for patients and physicians.

American Pain Foundation focuses on safety issues for common pain relievers

The American Pain Foundation (APF) recently released several resources focused on pain medication safety for acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) as a part of its PainSAFE™ educational initiative. The “Pain Does Not Discriminate” series of public service announcements reinforce for patients the importance of taking all pain medications as directed and safely storing medications and properly disposing all unused medications. The APF also offers information for patients that “recommends that people check their medication labels and be aware of what and how much they are taking, as well as pay attention to possible side effects.” The APF PainSAFE “Tools and Resources” page includes a link to a helpful guide from the FDA that counsels patients and consumers on the safe use of NSAIDs and drugs that contain acetaminophen.

The first question patients should ask is ‘What’s on the label?’

The American Chronic Pain Association (ACPA) 2011 Consumer Guide to Pain Medications and Treatments notes that “the two most common types of OTC pain relievers are acetaminophen and non-steroidal anti-inflammatory drugs,” and cautions patients who use OTC drugs for pain relief to “be aware that the brand name is often specific to the manufacturer and may not indicate the product’s active ingredients.” Patients are urged to “look for active ingredients, usually listed by generic name, on the label.” Knowledge and awareness of the medication’s active ingredients, dosage, and possible side effects are patients’ first responsibility when taking pain medications. The ACPA guide reminds patients that “the key to the effective use of OTC medications is understanding what you are taking and how much of it. You need to read the medication’s ingredients to know what you are taking. Be sure that the medication you select contains an appropriate amount of the drug you need for your symptoms and does not include medications or ingredients you do not need.”

The guide also draws special attention to the potential risks and dangers associated with acetaminophen use, highlighting the potential liver toxicity issues associated with excessive or long-term use of this drug by persons with liver problems or who regularly consume large quantities of alcohol. The maximum recommended dose for acetaminophen is four grams (4000 mg) in 24 hours. However, studies have shown that liver enzymes are elevated in some patients at 2000 mg.

Other acetaminophen safety facts and reminders for patients:

  • The abbreviation “APAP” on the label indicates the medicine contains acetaminophen (however, not all acetaminophen-containing drugs include this code)
  • Include both OTC medications and prescription medications when calculating daily acetaminophen intake
  • The maximum recommended dose of acetaminophen for heavy drinkers is 2000 mg in 24 hours
  • Long-term use of acetaminophen in combination with NSAIDs can increase the risk of renal complications
  • Prescription drugs that contain acetaminophen include Vicodin, Percocet, Lorcet, and Lortab

Despite risks, acetaminophen remains a valuable pain relief option

The National Pain Foundation (NPF) position statement on acetaminophen safety asserts that “acetaminophen is a safe and effective medication for relieving pain and reducing fever when used as directed,” and offers five safety tips for patients taking acetaminophen or medications that contain acetaminophen: do not exceed the recommended single dose and total daily dose; be aware that many OTC and prescription medications contain acetaminophen and learn where to look and what to look for on the label; ensure that all sources of acetaminophen are accounted for when calculating daily intake; safely store medications to keep them away from children and adult patients with cognitive impairments; and consult a physician before taking acetaminophen if the patient has chronic kidney or liver disease.

To promote the safe use of these valuable pain medications, the NPF supports greater efforts to improve “patient safety and responsibility through education and awareness about proper drug medication use among patient and physician communities.” Specifically, the NPF supports the use of more prominent labeling of risks of overdose on the packaging of acetaminophen products, spelling out acetaminophen on labels rather than use the abbreviation “APAP,” and other measures designed to enhance patient safety.

When it comes to safety, a picture may be worth a thousand lives

The authors of the previously mentioned study published in the American Journal of Preventive Medicine noted that “although health literacy research has emphasized the importance of plain, concise language, a number of studies also have found the use of icons or pictures to be helpful in drawing attention to and supporting patient comprehension and recall of medication information.” For their study, they developed several icons for identifying the presence of acetaminophen among a product’s list of ingredients, as well as icons designed to communicate to patients the maximum daily dose of the medication. They reported that study participants expressed a preference for labels that use an icon to identify products that contain acetaminophen (a hexagon enclosing the letters “Ac”), and were also “in favor of using an icon to highlight the maximum number of pills that can be safely taken in 1 day” (some variation of a red stop sign and text warning “stop at 6 pills in 24 hours”). These findings led the authors to conclude that given “the high prevalence of OTC medication use, it is possible a large number of adults will greatly benefit from the use of simple, explicit messages and icons as a more efficient manner of identifying acetaminophen medications and their maximum dose.” They also recommend further study to “to identify optimal ways to improve product labeling and educate the public on the meaning of icons and the importance of safe use of these medicines.”