June 16, 2024

Many people seeking pain relief turn to Tylenol, despite the risk of liver failure that it presents.

Advil. Tylenol. Motrin. Many of us have grabbed a bottle of one of these over-the-counter (OTC) pain medications when we encounter some sort of pain — whether its headaches, muscle pains or something else.But with so many options for OTC medications, is one pain medication better to use than the others?

When deciding which pain medication is best to use, it is important to first understand the differences among these pain medications. The major OTC pain medications fall into two groups: acetaminophen, better known as Tylenol, and nonsteroidal anti-inflammatory drugs, which include ibuprofen (Advil and Motrin) and aspirin. 

While the two classes of medication are often both used as an analgesic, or a pain reliever, they each have slightly different functions. Acetaminophen lessens fever and pain, while ibuprofen can relieve inflammation as well as pain and fever. However, if they use mostly the same mechanisms, why do some OTC pain medications work for some people and not others?

Dr. Bruce Prins, professor of biology and department chair of biological sciences, said many pain medications vary in effectiveness because everyone reacts to them differently.

“When I was doing research full time, I always worked with male white rabbits weighing five kilograms that were raised at this farm and fed this food because we’re trying to control things a lot,” Prins said. “Turns out humans have a lot of variability.”

External factors can impact the effectiveness of a pain medication. For example, taking pain medication on an empty stomach might work faster to relieve pain than taking the same dose after a large meal because absorption will take longer.

Since different pain medications have chemical differences, Prins also points to pharmacogenetic differences between people as a reason for differences in effectiveness. 

Although humans share many characteristics, people produce different receptor shapes and have genetic differences that lead to variable responses to medication.

“Mostly Tylenol works for all of us, but not everybody,” Prins said. “But then ibuprofen might work. I think the biotech/biopharma is kind of trying to strategize more and more toward specific differences.”

Amount of use in the past can also affect if a pain medication works or not. For example, when someone takes a pain medication for a long period of time, the body will need more as time goes on to relieve pain.

“If you have not been taking any (pain meds) for a long time, probably it’s going to be more effective when you take it,” Prins said. 

“It’s along the same route as drug addiction. The more you take it, the cells in the body adjust to that so they produce less receptors. Then, you have to take more to get the same effect and they produce less receptors. So you have to keep bumping up the dose to get the same effect. If you haven’t been doing that for a while, you start producing receptors.”

While choosing OTC pain medications, it is important to analyze risks of each medication. While OTC medications are relatively safe, especially at low doses, they can lead to toxicity, including kidney damage. OTC pain medcations are often perceived as completely safe, which can lead to dangerous conditions. For example, Tylenol can lead to liver failure.

“Acetaminophen-associated overdoses account for approximately 56,000 emergency department visits, 26,000 hospitalizations and over 450 deaths annually,” reads a 2014 study from U.S. Pharmacist. “Acetaminophen-induced liver toxicity has become the most common cause of acute liver failure and the second most common cause of liver failure requiring transplantation.”

Prins emphasizes that toxicity can occur at lower doses used over an extended period of time than many people assume, especially in older individuals.

“This bottle you just bought for $8 with 300 tablets in it could be a killer and it doesn’t mean that you ate them all,” Prins said. “It can be a killer at a much lower dose than that, so (with) all of them, there is potentially always a concern.”

Josh Ramirez, senior biomedical major, has used mainly ibuprofen (Advil) for pain and swelling in the past because this OTC medication was effective and non-addictive. He recommends assessing the potential pros and cons of taking any medication prior to use.

“I would want (people) to consider rate of addiction associate with (any) drugs and any side effects that would impact them,” Ramirez said. “They should consider if the benefits of taking the drug outweigh the cost of taking the drug.”

For those looking for the right OTC pain medication for them, Prins said people should analyze several factors, including what works for their bodies and the personal risk level of taking each medication.

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