10 Medicines That Work But We Don’t Know Why

Pharmaceutical companies conduct extensive trials before they can bring a drug to market. This is a matter of common sense. No one wants a repeat of the thalidomide scandal of the 1950s and 1960s, when some women took thalidomide for morning sickness. The result of the “greatest medical scandal ever created by man” was that 10,000 children were born with severe deformities.

Authorities closely monitor the research and development of new drugs to ensure they are as safe as possible and that doctors, pharmacists, and patients are aware of any potential side effects. But knowing that a drug works is not the same as knowing exactly how it works. The body is a complex mechanism that we still do not fully understand. Here are 10 drugs that work, but we don’t know why.

Related: The 10 Weirdest Things Doctors Prescribe Instead of Medication

10 Abatacept

In 2015, Science The magazine reported that some years earlier, a team of doctors in Cincinnati treated a sick 12-year-old boy. He had a rare genetic disease that mistakenly activated his immune system, causing considerable damage to his lungs and intestinal system. He had been sick for years and the doctors were desperately looking for a cure.

At this hospital visit, the staff evaluated him to see if he might benefit from a bone marrow transplant. They decided that his patient was too sick for the procedure. The doctors gave him abatacept knowing that it would not hurt him and that it might ease his pain.

People who take Abatacept will probably know this drug under its brand name Orencia. Doctors usually prescribe it for conditions like rheumatoid arthritis.

Doctors expected the Cincinnati boy to die, but he returned six months later in better health. The success of this drug, in this case, was a mystery.

9 Tylenol

Also known as acetaminophen, Tylenol is a favorite on American bathroom cabinets. It is an effective pain reliever that is perfectly safe as long as you follow the suggested dosage. Everyone knows about Tylenol, but no one is sure how it works.

There are three possibilities:

1. It could block an enzyme that makes our bodies feel pain.
2. It could be working on the endocannabinoid system. If this is true, Tylenol works like the THC in marijuana, which is also effective for treating pain.
3. It could be affecting the signals of the serotonin neurotransmitter. Serotonin is a chemical produced by brain cells that contributes to many cognitive functions.

It’s entirely possible that Tylenol is doing all three, or even none of them.

8 Lithium

Bipolar disorder, once known as manic depression, is a lifelong condition that causes mood swings ranging from severe depression to euphoria. Doctors prescribe lithium, under brand names such as Eskalith or Lithobid, as a widely recognized and effective treatment for the condition.

Lithium can reduce the severity and frequency of mania and reduce the risk of suicide when the victim is in a depressed state. People with bipolar disorder can take lithium for a long time as maintenance therapy. A doctor will make sure that his patient maintains a constant level of lithium in the body.

We know that lithium acts on the central nervous system, but we are not clear on what exactly it does. It could strengthen those connections in the brain that regulate mood and behavior, smooth out fluctuations and ensure the system works more steadily.

Lithium, the same metal we use in new batteries, is present in trace amounts in biological systems. Nobody knows what it does.

7 ulipristal

Ulipristal, marketed as Esmya, prevents pregnancy when someone has had unprotected sex or their birth control has failed. Ulipristal will prevent or delay the release of an egg. However, it can also change the lining of the uterus. It works, but we’re not sure how.

A person should take this medicine within five days of having unprotected sex. It is a particular drug that the user should only take due to this specific circumstance. It is important to note that ulipristal has no effect on sexually transmitted diseases.

6 paxlovid

There is a lot of information floating around the internet and social media about medications and which ones work or don’t. People are often looking for a solution to the condition and are willing to try anything they think might help, including antibiotics that cannot possibly treat a virus. Pharmaceutical companies were scrambling to find a drug that could work against the coronavirus while being cheap and easy to administer. In November 2021, Pfizer announced that its drug, Paxlovid, could reduce the hospitalization rate by nearly 90%.

Clinical trials showed that Paxlovid was safe, but questions remained. Paxlovid affects an enzyme in the body that helps the virus’s proteins develop into their final, dangerous state. Stop the work of the enzyme and you stop the development of the virus. But how it stops this replication is not yet understood.

Paxlovid looks very promising, but it includes a drug called ritonavir that can affect the way the body metabolizes other drugs. Anyone taking Paxlovid should tell their doctor if they are taking medication for other conditions. The exact effects that Paxlovid could cause are not fully known.

5 Valdecoxib

Under its trade name Bextra, this was a popular treatment for rheumatoid arthritis and related conditions. In 2005, the Food and Drug Administration (FDA) decided that its risks outweighed its benefits and stopped its sale. Bextra was effective but could cause heart, skin and stomach problems.

Valdecoxib is a good example of a drug that researchers designed to address a particular problem. In a class of NSAIDs called COX-2 inhibitors, it works by stopping the body’s production of a substance that causes pain and inflammation. However, it had broader effects than expected, although other COX-2 inhibitors did not, at least to the same degree. Pharmaceutical companies routinely run trial after trial until they think they’re sure they know what they’re dealing with. That’s why it takes so long to get FDA approval. But it can take years for the full range of side effects to emerge.

4 febuxostat

Gout is an incredibly painful condition. Traditionally, people thought it was a condition that only affected the wealthy, but no physical ailment is limited to a specific class of people. Gout is the result of having too much uric acid in the body, which causes crystals to form around the joints.

Febuxostat (under the brand name Uloric, among others) is a long-term treatment that reduces the production of uric acid. Doctors usually only prescribe febuxostat for patients who cannot tolerate allopurinol. They know that the drug is very effective against gout, but what is not so well understood is why some people suffer from debilitating side effects. These can include liver problems, joint pain, nausea, and skin rash. In some cases, patients go into anaphylactic shock, which can be fatal.

3 tofacitinib

Sold under the more common brand name, Xeljanz, this is another drug that doesn’t work as its developers hoped. A doctor may prescribe this medication for rheumatoid arthritis patients who cannot tolerate the more commonly used methotrexate.

Initial clinical trials revealed that some subjects developed upper respiratory tract infections, diarrhea, and headaches. After years of testing, the FDA approved the drug in 2012. Then, in 2014, a study showed that tofacitinib also turned white fatty tissues brown. Brown fatty tissues are more active and break down more easily than white ones. This unexpected result suggested that the drug could be an effective treatment for obesity. If this were true, it would suggest that the already expensive drug has a huge potential market.

It also suggests that the researchers didn’t really know how the drug worked. Some patients ended up with cancer or pulmonary embolisms. It’s worth noting that these side effects are very rare, but they do happen.

2 paroxetine

You may know this medication by its common trade names, Seroxat or Paxil. It’s an antidepressant, but doctors can prescribe it for a variety of disorders, including obsessive-compulsive disorder, panic attacks, post-traumatic stress, and social anxiety. It is also a useful treatment for premature ejaculation and menopausal hot flashes.

Paroxetine is a selective serotonin reuptake inhibitor. This morsel could suggest that scientists know what it does. Well yes and no. They know that paroxetine works, but they don’t know why. The best guess is that it increases the level of serotonin in the brain. The body produces serotonin from an essential amino acid called tryptophan.

Foods like cheese, nuts, and red meat contain tryptophan. Your general well-being depends on having an optimal level of serotonin in your system. This chemical affects your physiological functions, behavior, cognition, learning, memory, and mood. Researchers don’t really know how paroxetine works because they don’t fully understand the complex functions of serotonin.

1 Aspirin

Aspirin’s popularity waned in the 1960s as other pain relievers came on the market. But then scientists realized that “aspirin” was not just a pain reliever. It was also very effective as a blood thinner and could reduce the chance of heart attacks or strokes. Some doctors suggest that regular use of low-strength aspirin may be beneficial, although others are cautious.

Recent research in Sweden suggests that aspirin has another beneficial effect. Using a database containing details of 80,000 cancer patients, a Swedish team found that if a patient with colon or lung cancer had regularly taken low-strength aspirin before diagnosis, their tumor tended to be less advanced. Doctors can treat less advanced tumors more effectively.

This correlation was strong enough that the team was confident that the link was not due to a statistical anomaly. The puzzle now was to find out why aspirin might have this effect. The jury is still out, but it could be that aspirin’s anti-inflammatory properties slow DNA damage that can lead to cancer.