How Do Painkillers Find & Kill Pain?


First, we need to make a distinction between the two main classes of painkillers, which are used for different situations and function via different mechanisms.

The first class is the narcotic opioid drugs. These are the heavy-duty drugs, like morphine and codeine, used to treat severe pain. They relieve pain in two ways: first by interfering with and blocking the transmission of pain signals to the brain, and then by working in the brain to alter the sensation of pain. These drugs neither find nor kill pain, but reduce and alter the user's perception of the pain. They're kind of like having an optimistic friend that says, "Hey man, everything will be cool. Nothing's wrong. Here, look at this shiny, distracting thing!"

The other class is the aspirin drugs, like paracetamol and ibuprofen. These are the over the counter drugs we reach for whenever we've got a headache or a sore back. Throughout history, people all over the world were using botanical remedies for pain. The ancient Egyptians used leaves from the myrtle bush, Europeans chewed on hunks of willow bark and Native Americans did the same with birch bark. In the nineteenth century, scientists isolated the chemical in all these plants that gave them their pain relieving properties: salicin (which is metabolized to salicylic acid when consumed). They also discovered that these chemicals produced the side effect of horrendous digestive problems (which answers that other burning question, "Why is that Native American in that old commercial crying?").

Bayer aspirin

Eventually, a scientist at Bayer Pharmaceutical synthesized a less harmful derivative chemical, acetylsalicylic acid (ASA). Bayer dubbed it Aspirin and commercialized it. Hoffmann went on to develop a "non-addictive" substitute for morphine. The resulting product, heroin, was less successful than aspirin.

Despite its long history, we didn't discover how aspirin works until the early 1970s. Unlike narcotics, aspirin drugs are real workhorses that actually go to the source of pain and stop it. When cells are damaged, they produce large quantities of an enzyme called cyclooxygenase-2. This enzyme, in turn, produces chemicals called prostaglandins, which send pain signals to the brain. They also cause the area that has been damaged to release fluid from the blood to create a cushion so the damaged cells don't take any more of a beating. This cushion is the swelling and inflammation that goes along with our aches and pains. When we take aspirin, it dissolves in our stomachs and travels through the whole body via the bloodstream. Although it's everywhere, it only works its magic at the site of cell damage by binding to the cylooxygenase-2 enzymes and stopping them from prostaglandins. No more prostaglandins means no more pain signals. The cells at the damage site, of course, are still damaged, but we're left blissfully unaware.

This prostaglandin-stopping power is also why people take aspirin regularly to reduce the risk of heart attacks, since prostaglandins in the bloodstream can cause clotting. Additionally, aspirin reduces the production of thromboxane, a chemical that makes platelets, a type of blood cell, sticky. With aspirin in our systems, platelets make less thromboxane and are less likely to form a clot and block an artery.

10 Things You Should Know About Asthma Kozielczyk Kozielczyk

To anyone with asthma, the feeling of an attack is unmistakable. Patients have compared an asthma attack's feeling of breathlessness, caused by inflammation in the lungs and airways, to being smothered by a pillow or having an elephant sit on their chest. Medical experts have already figured out some aspects of asthma, like how to diagnose and treat it, but other components, like what causes asthma and how to cure it, remain unclear. From the triggers people encounter at work to the connection to allergies, here are some facts about asthma symptoms and treatments you should know.

1. Asthma attacks are related to allergies.

The physical process that occurs when someone has a sneezing fit during pollen season is similar to what happens during an asthma attack. But while the former causes discomfort, the latter produces potentially life-threatening symptoms. When people with allergies are exposed to an allergen like pollen, they produce antibodies that bind to that allergen. This signals the body to release the chemicals that cause allergic symptoms. In most people, the symptoms are limited to the head, such as a runny nose or watery eyes, but in people with asthma, they're felt in the lungs. If the lungs are inflamed, the airways that carry air swell up and fill with mucus, constricting airflow and causing common asthma symptoms like coughing, wheezing, and shortness of breath. Such asthma attacks can be fatal when patients can’t get enough air to their lungs.

2. Asthma is the most prevalent chronic disease among children.

Asthma is common, affecting 25 million in the U.S. alone, and of those patients, about 7 million are children. Most people with the disease develop it during childhood. Asthma is the most prevalent chronic illness among kids, and each year, students miss 13.8 million school days because of it.

3. Asthma may be inherited.

Doctors aren’t entirely sure what causes asthma, but they know it sometimes runs in families. A 2010 study found that people with one parent with the condition were nearly twice as likely to have it themselves, and people with a parent and a grandparent with asthma were four times more likely to develop it. Because asthma is connected to allergies, a genetic disposition toward allergies, known as atopy, may explain some inherited asthma cases.

4. Asthma is surprisingly easy to diagnose.

One of the simplest ways to diagnose asthma is through a lung function test. If a patient is reporting asthma symptoms (coughing, chest tightness, a feeling of not getting enough air), their doctor may check the strength of their exhalations before and after having them use an inhaler. If their breathing improves with the medicine, they likely have asthma. An X-ray of the patient’s chest can also be used to reach an asthma diagnosis.

5. Kids who grow up around germs are less likely to have asthma.

A person’s environment early in life may also play a role in whether or not they develop asthma. People who grew up in rural areas, around animals, and in large families are less likely to have asthma than those who did not. One possible explanation is the hygiene hypothesis: According to this theory, kids who were exposed to germs and pathogens while their immune systems were developing are better equipped to deal with allergens, while kids who were sheltered from germs may be more likely to have an exaggerated (and in the case of asthma, potentially deadly) immune response to harmless substances. The hygiene hypothesis hasn’t been proven, however, and it’s definitely not an excuse to expose children to infections in an attempt to strengthen them against asthma attacks in the future.

6. Asthma triggers are everywhere.

To manage their symptoms, doctors tell asthma patients to limit exposure to their triggers when possible. Common asthma triggers include irritants and allergens like dust, tobacco smoke, car exhaust, mold, pet dander, and smoke from burning wood. Triggers that don’t come from the environment, like colds, sinus infections, acid reflux, and hyperventilation brought on by stress, can be even harder to avoid.

7. There's one asthma trigger patients shouldn't avoid.

Physical activity causes fast breathing, which can provoke asthma attacks in some people with the condition. There’s even a type of asthma called exercise-induced bronchoconstriction that specifically describes people who suffer from these kinds of attacks. But the risks of living a sedentary lifestyle outweigh those of exercising carefully, even with asthma. Instead of cutting out cardio altogether, doctors work with patients to come up with an exercise plan that’s safe for them. This might include warming up and using an inhaler before working out, practicing cool-down activities afterward, and wearing scarves or masks to limit exposure to irritants that may also trigger asthma symptoms.

8. There are two types of asthma treatments.

Long-term controllers and quick-relievers are the two types of medications used to treat asthma. Immediate medicines like short-acting beta agonists and anticholinergics relax muscles in the airways when flare-ups occur, and they’re typically administered directly to the lungs with an inhaler. Long-term medications help keep asthma symptoms under control over time are taken as often as once a day, regardless of whether symptoms are present. They include inhaled long-acting beta agonists and corticosteroids, biologic injections, and theophylline and leukotriene modifier pills and liquids. All of these medications suppress asthma symptoms by either relaxing muscles, reducing swelling, or preventing inflammation in the airways.

9. Asthma can be an occupational hazard.

Occupational asthma develops when a patient’s triggers come from their work environment. According to the National Institutes of Health, wood dust, grain dust, animal dander, fungi, and various chemicals are some of the most common asthma triggers that patients encounter in the workplace. Bakers, farmers, laboratory workers, millers, and woodworkers predisposed to asthma are all at higher risk.

10. There's no cure for asthma, but symptoms can lessen over time.

Though asthma is treatable, there’s no cure for the chronic illness. Some people, however, do appear to grow out of the condition after suffering from it as kids. It’s possible for asthma symptoms to become less severe and go into remission as patients get older, but once someone is diagnosed with asthma, the risk of an episode never goes away completely. Changes in hormone levels are a factor that could possibly bring asthma symptoms back in patients who haven’t experienced an attack in years.

7 Facts About the Measles

Abid Katib, Getty Images
Abid Katib, Getty Images

The measles used to be one of the world’s most common childhood diseases. Since the introduction of the measles vaccine, however, the disease is rarely seen in the U.S. But people still have reason for concern about symptoms like the telltale measles rash: In 2018, there were 349 reported cases of the measles across 26 states and Washington, D.C. The year before, 120 people contracted the disease. Here are seven things to know about measles symptoms and treatments.

1. Everyone used to get the measles.

There was a time not so long ago when exhibiting measles symptoms was a near-ubiquitous part of childhood. In the 4th century CE, Chinese alchemist Ko Hung wrote of the differences between smallpox and measles, and the disease was described in the 9th century by the famous Persian physician Rhazes. There were major epidemics of the disease in the 11th and 12th centuries [PDF].

In the years before the first licensed measles vaccine appeared in the U.S. in 1963, an estimated 90 percent of children caught the measles before they were 15. The disease was a leading cause of death for children—and in some places without access to vaccinations and medical care, it still is. Today, up to 5 percent of children in places without access to good medical care die of the measles annually.

The CDC estimates that prior to the existence of the measles vaccine, there were between 3 and 4 million measles cases in the U.S. per year, approximately 400 to 500 of them fatal—but vaccinations have reduced the prevalence of the disease by 99 percent. In some years, fewer than 100 people contract the disease in the U.S.

2. The measles virus is highly contagious.

The measles virus is considered one of the most contagious viruses around: Without vaccination, around 90 percent of people who are exposed to the virus will become infected.

The disease is caused by the spread of a type of virus called morbillivirus, which can be transmitted through the air via breathing, coughing, or sneezing. The virus can live in the air for up to two hours after an infected person coughed—meaning that you don’t necessarily need to be standing next to someone with the measles to get it from them.

3. It can cause more than just a measles rash.

A person exposed to measles will begin to show symptoms seven to 14 days after exposure. Common measles symptoms include coughing, congestion, fever, and most famously, a full-body skin rash. But a third of measles cases involve complications ranging from diarrhea to pneumonia, brain swelling, and coma. Pneumonia causes around 60 percent of fatalities when it comes to measles complications.

Children under 5 are particularly at risk of getting complications and dying from the disease. One in 10 will contract an ear infection, possibly leading to permanent hearing damage, and one in 20 will get pneumonia. One or two out of every 1000 kids who contract the measles will die, according to the CDC, many from pneumonia.

4. The measles vaccine is very effective.

The measles is combined with vaccines against two other diseases—mumps and rubella—and when administered as designed, it's incredibly effective. Experts recommend that children get their first dose of the MMR vaccine on their first birthday (but not before). Then, they should get the second dose before they enter kindergarten. If a child doesn’t get vaccinated before they’re 12, they should still get the vaccine: two doses a month apart. In most cases, those two doses of the vaccine should be enough to give you immunity for life (although some experts are now cautioning booster shots may be a good idea for some adults).

If you’re exposed to the virus and haven’t been vaccinated, an immediate dose of the vaccine can provide some protection from the disease, as long as you get it within 72 hours of exposure.

5. Measles is considered eliminated in the U.S. ...

Thanks to effective vaccinations, as of 2000, measles is no longer a threat in the U.S., according to the CDC’s standards. The disease is considered eliminated, which means that it hasn’t been continuously transmitted in a specific geographical location for at least a year. So even if there’s the occasional outbreak of cases, it’s considered eliminated because it’s not a constant threat anymore. In 2016, the World Health Organization declared the disease to be eliminated across the entirety of North and South America.

6. ... But you should still get vaccinated.

Measles isn’t prevalent in the U.S., but that doesn’t mean you can skip your vaccinations: Though home-grown measles has been eliminated, people in the U.S. still come down with it. That’s because measles is still a major issue elsewhere in the world, and travelers can bring it home with them, spreading it to unvaccinated populations in the U.S.

That includes babies. Children under 5 are one of the most vulnerable populations when it comes to measles infections, but babies aren’t generally vaccinated until they’re 12 months old (the CDC recommends that before international travel, “infants 6 months through 11 months of age should receive one dose of MMR vaccine” and then get a shot again when they’re a little older). That makes it incredibly important for everyone around them to be vaccinated, so that the disease can’t spread.

In addition to inoculating individuals against diseases, the measles vaccine operates on the principle of herd immunity. When nearly an entire population is vaccinated, it’s very hard for the disease to spread. That protects people who aren’t inoculated, like babies, or people whose bodies didn’t respond to the vaccine for whatever reason.

7. People still get measles in America.

Since measles was declared eliminated in 2000, there have been relatively few cases reported here, but a significant number of people have caught the disease in the past few years. In 2004, there were just 37 cases of measles reported in the U.S. Ten years later, in 2014, there were 667—most of whom were people who weren’t vaccinated. (That number was unusually high, and went down to 188 cases the next year.)

The CDC blames recent measles outbreaks on low rates of vaccination. One 2016 review of measles studies found that out of 970 measles cases, almost 42 percent of patients had opted out of getting the vaccine for non-medical reasons.

Europe has also seen a surge in measles cases in the last few years. Between 2016 and 2017, measles cases in Europe quadrupled, from 5273 cases to more than 21,000, according to the World Health Organization. Thirty-five of those 21,000 people died from the disease. This is bad news for Americans, too, since most U.S. measles cases can be linked back to travelers coming into the U.S. from places like Europe. So get your vaccinations!