The amount of acetaminophen that is contained in popular prescription painkillers like Vicodin and Percocet is being limited by the FDA in response to a growing number of reports involving liver damage from acetaminophen side effects.
The FDA announced on Thursday that the amount of acetaminophen in combination painkillers should be limited to no more than 325 mg in each tablet or capsule. Many prescription painkillers containing acetaminophen currently have much higher amounts, in some cases up to 750mg of acetaminophen per dose.
Under the new requirements, drug makers will need to reformulate their medications to reduce the amount of acetaminophen or recall the drugs from the market. The limits currently only apply to prescription products, with over-the-counter painkillers like Extra-Strength Tylenol unaffected. The requirements will be phased in over three years and the FDA said it does not believe the limits will cause a shortage of pain medications.
Stronger warnings about the risk of acetaminophen liver injury are also being required on all prescription combination painkillers that contain acetaminophen. The FDA has proposed that a “black box” warning about the risk for severe liver injury be added to all acetaminophen products, which is the strongest warning that can be placed on a prescription medication.
According to the FDA, most of the reports of sever liver injury involved cases where consumers took more than the prescribed dose within a 24-hour period, took more than one product containing acetaminophen at the same time or drank alcohol while taking acetaminophen.
Acetaminophen is the main ingredient in Tylenol and used in many cold medicines, but it is also often combined with powerful painkillers. Drugs affected by the new acetaminophen limits include Vicodin (acetaminophen and hydrocodone), Percocet (acetaminophen and oxycodone), and Tylenol with Codeine (acetaminophen and codeine).
In July, an FDA advisory panel said users of medications that combine acetaminophen with narcotics increase the danger of acetaminophen liver damage and overdose because patients who take the drugs for long periods often need higher and higher doses to achieve the same effect. This means that their livers are receiving higher and higher doses of acetaminophen.
During that meeting the panel narrowly voted 20-17 in favor of a recall of Vicodin, Percocet and five other prescription painkillers that combine narcotics with acetaminophen. The panel voted 36-1 that they should carry a “black box” warning if they were allowed to stay on the market.
Vicodin and generics that use the same active ingredients are prescribed more than 100 million times a year in the United States. However, safety issues are a serious concern, as more than 400 people per year die, and 42,000 are hospitalized, from overdoses due to drugs that use acetaminophen.