PRODUCTS CONTAINING ACETAMINOPHEN
Which one of us does not pop a pain killer when we have headaches, arthritis pain or sore muscles? How about when we have coughs, colds, the flu, allergies, fever, or tooth aches? It is very prevalent for people with lupus, along with all of those healthy people, to take over-the-counter medication. But did you know that you are at risk of serious health problems from taking medicines containing acetaminophen (ACET).
Taking too much acetaminophen can cause liver damage - sometimes serious enough to require liver transplants or cause death. ACET is the leading cause of liver failure in the US. It sends 56,000 people to emergency rooms each year. Half of those people unintentionally overdosed.
And just how easy is it to exceed the daily limit of 4000 mgs? Extra strength Tylenol contains 500 mgs of acetaminophen and regular Tylenol contains 325 mgs. Some medicines including ACET contain 650 mgs or even 1000 mgs. In the case of Extra Strength Tylenol , If you follow the dosage instructions of up to 2 tablets every four hours you would consume 6000 mgs (150% of the daily limit) thus overdose.
The Federal Drug Administration working group reviewed the FDA adverse event data base and a large liver failure study and found the liver damage occurs in the range of 5000 – 7500 mgs in 24 hours. The working group recommended that the daily limit be reduced to 10 regular pills (3250 mgs) a day. This recommendation has not been implemented.
Acetaminophen is known by many other names (APAP, N-acetyl-para-aminophenol, and paracetamol.) It is widely available in more than 200 medications. It is also contained in prescription pain medications such as Vicodin, Percocet , and Oxycodone that are widely used. In one year, 200 million prescriptions containing acetaminophen were dispensed in the U.S.
The fact that so many medicines contain acetaminophen increases the danger of an overdose. “The risk of liver injury primarily occurs when patients take multiple products containing acetaminophen at one time and exceed the current maximum dose of 4000 mgs within a 24 hour period “said Dr. Sandra Kweder, the FDA’s deputy director for new drugs.
Tylenol is just one of 44 brand names of acetaminophen. Additionally, it is found in medicine combined with other drugs. Some names you may recognize are some forms of Robaxcet Anacin, Alka-Selzer ,Dimetapp, Sudafed, Dayquil, Dristan, Robitussin, Excedrine. Midol PMS, Vicks 44 ….. For a complete list see the MedPlus website cited at the end of this blog.
Another consideration is consuming ACET while using alcohol or drugs. It increases the risk of liver damage especially amongst older people who have a lower ability to clear drugs from their systems. For those who consume alcohol regularly, the daily limit of ACET is 2000 mgs a day. This works out to 4 Extra Strength Tylenol a day. Some doctors recommend that you should not use alcohol when using any over-the-counter or prescription medicines.
According to the FDA if you drink 3 or more alcoholic beverages a day you should consult with your doctor about a safe dose of ACET. I may be naïve but I think that heavy drinkers are unlikely to bring this up with their doctors. But just think of all the heavy drinkers that take Tylenol for hangovers! The damage caused by ACET is more likely to occur when it is taken after alcohol is metabolized.
Even one overdose of acetaminophen can cause permanent liver damage. Call poison control as soon as possible, in case of an overdose. There is an antidote named N Acetycystein which is most effective if taken within 8 hours of ingesting the ACT. Don’t hesitate even if you feel well. The symptoms of an overdose may not appear for up to 24 hours. They include abdominal pain, nausea, vomiting, not feeling well, unable to eat, and a poor appetite.
WHAT ABOUT SAFEGUARDS?
Reducing the amount of ACET in medications
Due to evidence linking it to liver failure, the American Food and Drug Administration has capped the amount of acetaminophen to 325 milligrams per capsule in prescription painkillers. However, they have not followed the recommendations of the FDA working group to also lower the dose of acetaminophen in the over-the-counter products.
Labeling
4000 mgs is the stated limit on Tylenol bottles but that leaves little margin for safety. There is no mention of permanent liver damage caused by exceeding the limit. This dosage instructions would be more explanatory if it read “1-2 tablets every four to six hours but not to exceed 8 tablets a day or permanent liver damage may occur in a healthy adult.
In Canada there is no requirement to place warnings on bottles of extra strength ACET. However, in 2009, Health Canada issued a voluntary warning for ACET bottles. It reads” taking more than the maximum daily does may cause severe or possibly fatal liver damage.”
Monitoring and Education
Have you been questioned about what over-the-counter medications you take? I haven’t. The prescription information sheets issued with your prescription says that you should inform your doctor or pharmacist of all of the prescriptions and over-the-counter medicines you take. Without this information just how are pharmacists able to monitor drug interactions?
Given the potential for unintended abuse, it would be appropriate for doctors to question and warn their patients about the risks of using too much acetaminophen and for pharmacists to warn patients particularly those with chronic pain conditions. What could be even more effective would be to have all purchases containing ACET rung through the pharmacy till so people can be warned about the dangers of overdosing when using multiple medicines.
SO REMEMBER, the next time you are buying over-the- counter medication, be sure to check the label closely and ask the pharmacist about interactions with your prescriptions.
SOURCES:
www.agingincanada.ca/dangers_ of_ acetaminophen.htm
http://www.hc-sc.gc.ca/dhp-mps/prodpharma/applic-demande/guide-ld/label_stand_guided_ld-eng.php#a6-1
