Sometimes I Notice Acetaminophen (or Tylenol) is Effective for Relief, Other Days It Is Not. Why?
*written by Andrew Akhaphong, Mackenthun's Registered & Licensed Dietitian Updated: August 30, 2021
When it comes to medication therapy we often think about the doctors or pharmacists for medication regimen education; however, many forget registered dietitians can do that too. After all, registered dietitians are also licensed healthcare providers.
So why are registered dietitians able to provide medication regimen education?
Many medications have interactions with food, drink, and even herbal/natural supplements that may either decrease or increase effectiveness of specific medications. It is important for registered dietitians to review your medication regimen along with your usual dietary history to examine any potential issues that may come about with your medication therapy.
Chemical Structure of Acetaminophen. Image Source: https://www.researchgate.net/profile/Paromita-Seal/publication/301534145/figure/fig1/AS:794991119044608@1566552061601/Chemical-structure-of-acetaminophen.png
Acetaminophen is a generic drug name in the class of medications called NSAIDs or non-steroidal anti-inflammatory drug. Brands that use acetaminophen include Tylenol®, Advil®, Excedrin®, and Vick's®. The generic and brands are easily obtainable over-the-counter; however, some prescription drugs may contain acetaminophen too such as Vicodin®.
Acetaminophen is used to treat mild to moderate and pain, to treat moderate to severe pain in conjunction with opiates, or to reduce fever. Common conditions that acetaminophen treats include headache, muscle aches, arthritis, backache, toothaches, sore throat, colds, flu, and fevers.
Acetaminophen gets absorbed primarily in the small intestine. Here, it is absorbed into the bloodstream and gets metabolized by the liver whose waste is then excreted via urination.
Pectin is a fiber that comes from fruits. Citrus fruits and apples are especially highest in pectin including fruit-derived products like jelly, jam, dried fruit, and fruit leather. In the human body, pectin works as a soluble fiber. This means soluble fiber gels up and absorbs like a sponge, binding to digested nutrients and medications.
Cruciferous vegetables, especially those of the cabbage family which includes kale, kohlrabi, broccoli, cauliflower, contain a family of antioxidants known as phytochemicals. Phytochemicals support the immune system by improving activity of enzymes and white blood cells.
Research within the past 10 years have shown that a diet rich in high-pectin fruits and cruciferous vegetables interfere with the enzymes CYP1A2 and glutathione S-transferase-alpha. These enzymes are responsible for metabolizing acetaminophen.
In a 2020 literature review published in the journal of Clinical Pharmacology and Therapeutics by Eagles, Gross, and McLachlan, the researchers found the enzyme activity increases by 20-35%; faster enzymatic activity means faster metabolism (or breakdown) of acetaminophen before it can kick into its full effects.
In a 2011 study by Navarro and colleagues published in The Journal of Drug Metabolism and Disposition, they found an intake of more than 10 servings of high-pectin fruits and cruciferous vegetables (combined) significantly increases the activity of glutathione S-transferase-alpha.
Alcohol is also recommended to avoid or limit when taking acetaminophen. Because alcohol also metabolizes in the liver, restricting alcohol intake when taking acetaminophen will allow the liver to metabolize acetaminophen appropriately while reducing the risk for liver toxicity and developing liver failure. One night of one or two alcoholic beverages with a standard dose of acetaminophen is not going to be harmful, but a consistent pattern of alcohol intake with acetaminophen use will.
Recommendations
Follow directions by manufacturer printed on the drug label.
Take acetaminophen two hours before, or, two hours after consumption of a diet with high-pectin fruits and/or cruciferous vegetables.
The liver metabolizes one alcoholic drink serving per hour. Take acetaminophen at least two hours before alcohol consumption, or, based on a specific amount of hours equal to amount of alcoholic drink servings.
Always include your doctor and a pharmacist when discussing medications. Effectiveness may be influenced by other factors besides the food you eat.
Sources: Eagles, S. K., Gross, A. S., and McLachlan, M. J. 2020. The effects of cruciferous vegetable-enriched diets on drug metabolism: A systematic review and meta-analysis of dietary intervention trials in humans. Journal of Clinical Pharmacology and Therapeutics. 108(2), 212-227. Navarro, S.L., Chen, Y., Li, L., Li, S.S., Chang, J. L., Schwarz, Y., et al. (2011). UGT1A6 and UGT2B15 polymorphisms and acetaminophen conjugation in response to a randomized, controlled diet of select fruits and vegetables. Drug Metabolism and Disposition. 39(9), p. 1650-1657. Pronsky, Z. M. and Crowe J. P. 2010. Food-Medication Interactions. 16th ed. https://www.sciencedirect.com/science/article/pii/S102194981730203X https://ascpt.onlinelibrary.wiley.com/doi/abs/10.1002/cpt.1811 https://www.peacehealth.org/medical-topics/id/hn-10000222 https://www.rxlist.com/cabbage/supplements.htm https://www.drugs.com/acetaminophen.html