The U.S. Food and Drug Administration (FDA) has issued a warning to consumers that there is no way to predict whether a patient may experience liver damage from Tylenol or other acetaminophen-based medications.

The agency further warned that liver damage is most often caused by Tylenol overdose, but cases have occurred even under general use.

“Acetaminophen when used as labeled is generally considered to be safe. But overdoses of acetaminophen are the most common cause of drug-related liver injury, whether these occur accidentally or otherwise. With acetaminophen overdoses, some people get a more severe reaction than others,” the FDA’s Dr. Mark Avigan said in the update.

Tylenol is one of the most widely used painkiller medications in the United States, and is used by millions of patients for minor to severe pains. Tylenol’s most prominent ingredient, acetaminophen, is a popular pharmaceutical ingredient for pain treatment medications.

The FDA indicates that Tylenol and other acetaminophen drugs may be responsible for more than 50,000 emergency room visits each year including 25,000 hospitalizations and over 450 deaths annually. Due to the numbers of adverse events, several awareness efforts have been launched in an effort to inform the public about the potential dangers. Some experts believe most of these incidents come from patients unnecessarily taking the medications, and when consumers take a variety of different medications containing acetaminophen, causing an accidental overdose.

Additionally, due to the high dosage of acetaminophen in Extra Strength Tylenol and generic equivalents, consumers may also inadvertently overdose if they take more than two pills at a time or fail to monitor the rate they ingest the pills. The consumer update also illustrates the FDA’s efforts to prevent overdoses, with the first acetaminophen warning released in January. The first warning had recommended doctors and pharmacists to discontinue prescribing and dispensing combination acetaminophen pain killers.

The next warning was released on April 28, requesting healthcare providers and pharmacists to remove high dosage acetaminophen drugs from their inventories. However, critics note that despite the efforts made by healthcare providers, consumers remain widely unaware of the liver damage side effects.

Overview of Tylenol Liver Damage Awareness Effort

Over the past several years, awareness efforts have been put forward to inform consumers about the increased risk of liver damage associated with Extra Strength Tylenol and other high dosage acetaminophen drugs. However, given how common the complications seems to be, critics call for further action. The manufacturing company of brand name Tylenol, Johnson & Johnson, has taken several steps to help remedy the situation.

For example, the company lowered the maximum recommended dosage of Tylenol and other acetaminophen drugs from 4,000 mg per day to 3,000 mg per day in 2011. However, Johnson & Johnson also continues to market Tylenol as being a safe and effective treatment, with few consumers realizing the risks. Johnson & Johnson is currently facing a number of Tylenol liver damage lawsuits filed in courts throughout the country.

The Tylenol lawsuits allege that Johnson & Johnson built up Tylenol’s reputation based on deceptive marketing, and concealing information about the potential risk of liver damage.