Why taking fever-reducing meds and drinking fluids may not be the best way to treat flu and fever

As flu season progresses, so does the chorus of advice, professional and otherwise, to drink plenty of fluids and take fever-reducing medications, like acetaminophen, ibuprofen or aspirin.

These recommendations, well-intentioned and firmly entrenched, offer comfort to those sidelined with fever, flu or vaccine side effects. But you may be surprised to learn the science supporting these recommendations is speculative at best, harmful at worst and comes with caveats.

I am an exercise physiologist who specializes in studying how the body regulates fluids and temperature. And based on a wide body of evidence, I can tell you that increased fluid intake and taking fever reducers, whether aspirin, acetaminophen or ibuprofen, may not always help in your recovery. In fact, in some cases, it could be harmful.

There’s a reason why people say fevers should be lowered when sick or after a vaccine. Both aspirin and acetaminophen, such as Tylenol, reduce fever, headaches and muscle aches. But at the same time, seminal and newer studies, including broad meta-analysis studies, show that these medications may weaken the immune response to infection or have unwanted side effects.

What is a fever?

First, some background: Fevers are a regulated increase in core body temperature as a response to unwanted microbial invaders.
The more severe the infection, the higher the fever.

Having a fever is not all bad; it’s how the body has evolved to recuperate from an infection. For many species, fevers are advantageous and beneficial for survival.

But fever comes with a cost. A body temperature that’s too high can be deadly. For every increase of 1.8 degrees Fahrenheit, metabolism goes up 10%; the body begins to burn more calories than normal, temperature continues to rise and the body releases hormones to keep fever under control.

Many studies demonstrate what can happen when fever reducers are thrust into this complex dance. It turns out aspirin or acetaminophen may cause infected people to feel better, but they also spread more virus while suppressing their own immune response to the infection.

In one double-blind, placebo-controlled study, healthy people infected with a cold virus who took aspirin or acetaminophen for a week had a reduced immune response and an increase in viral shedding – meaning producing and expelling virus particles from the nose. Another study showed that taking aspirin effectively reduced fever symptoms but increased shedding.

Although some of those traditional studies took place decades ago, their results still hold up today. A recent study warned that if everyone took fever suppressants, there would be even more flu cases and flu-related deaths. Furthermore, elevated body temperature – or fever – can help fight COVID-19 by reducing the growth of the virus within the lungs. In other words, fevers can help the body fight viruses while reducing the rate of death and disease.

Drinking fluids

To prevent dehydration, the Centers for Disease Control and Prevention recommends drinking more fluids when one has a fever or infection, or has received a COVID-19 vaccine. But there is scant scientific evidence to support this recommendation.

Drinking fluids to excess can lead to overhydration.
Dina Morozova/iStock via Getty Images Plus

It’s true that drinking fluids when dehydrated is necessary to reduce fever. But not everyone with a fever is dehydrated. For those who aren’t thirsty, forcing fluids beyond thirst, which is often unpleasant, may not be advisable.

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A study that evaluated the advice to “drink plenty of fluids” determined that increasing fluid intake when sick may not offer benefits, and that more high-quality studies are needed. Indeed, there was a potential risk from overhydration. For some people, three liters, or about 12 eight-ounce glasses, is too much. Overhydration can cause nausea and vomiting, headaches and cramps; in severe cases, excessive fluid intake can cause seizures or coma.

Here’s why this happens. To stop dangerous escalations in fever, the body releases antidiuretic hormones. Urination is diminished, so the body retains water through the actions of the kidneys. So if someone with a fever drinks more water than necessary, water intoxication – or hyponatremia, a potentially fatal medical condition in which a patient’s blood sodium levels are too low – could follow.

One study found that nearly a quarter of patients who came to the hospital with COVID-19 had hyponatremia upon admission. In that study, hyponatremia increased the need for breathing support in the form of ventilation. And another study showed that the condition can lead to poorer outcomes in COVID-19 patients.

So maybe it’s time to rethink the conventional wisdom. If the fever is mild or moderate, stay warm, even use blankets, rather than try to actively reduce it. Rest, so your body can fight the fever. Conserve energy because your metabolism is already on overdrive. Use fever-reducing medications sparingly. Drink fluids, but only to tolerance, and preferably when thirsty.

And one final suggestion that should be soothing: When fighting a fever or vaccine side effects, consider sipping warm liquids that contain sodium. Broths containing sodium, like bullion, may help avoid hyponatremia. And although the actual scientific evidence is sparse and conflicting, chicken soup may be a better antidote than water when fending off a fever or flu symptoms.

How Does Acetaminophen Work? | Tufts University School of Medicine

September 14, 2022

It’s still kind of a mystery exactly how it relieves fever and pain, says Allen Shaughnessy, Pharm.D., a Tufts professor of family medicine

by Allen Shaughnessy, Pharm.D., M.Med.Ed., professor of family medicine

Who hasn’t taken acetaminophen? Known by brand names as Tylenol, Panadol, or just “non-aspirin pain reliever,” we’ve used it to treat our headaches, pains, and fevers. Ubiquitous in medicine cabinets, it has been around a long time—acetaminophen was first synthesized in 1878 and first used to treat pain and fever in 1893.

Yet it didn’t come into widespread use until 1950 when Tylenol Elixir for Children, originally a prescription medicine, was marketed as an alternative to aspirin.

How does it work? Like many medications, acetaminophen—known as paracetamol outside the U.S. and Japan—was originally derived from coal tar, a derivative of coal from which we get several medicines and even food and clothing dyes, especially the deep blues and purples.

It was discovered by accident. A researcher investigating a treatment for intestinal worms asked for a product to study, but was given the wrong chemical instead—acetanilide—that had no effect on worms. It did, though, lower fever. Acetanilide has side effects, though, and acetaminophen was derived from it to be a safer alternative.

Acetaminophen has two actions in the body: reducing fever and providing relief for mild to moderate pain. Though it has been studied for almost 150 years, how it works remains a mystery.

That it works for many causes of pain, from a toothache to stubbed toe, signals that it works in the central nervous system, rather than at the site of pain like local anesthetics or analgesics such as ibuprofen or aspirin. Similarly, it also is likely to work in the brain to control the mechanism used by the body to elevate body temperature.

Several mechanisms were proposed, only to be refuted by subsequent studies. Its effects on serotonin in the brain and even on endocannabinoid receptors—where cannabis exerts its action in the brain—have been explored.

The most promising, yet still speculative, explanation is that it works on one of the cyclooxygenase (COX) enzymes. Blocking this enzyme at the cause of the pain is the mechanism by which nonsteroidal anti-inflammatory drugs (NSAIDS) work. But the effect of acetaminophen at the pain site is too weak to be responsible for relief. However, acetaminophen might block the enzyme production in the brain, thus blocking the further transmission of the pain nerve impulses.

As with other pain relievers except opioids, such as morphine, it has a “ceiling effect” to its pain-relieving abilities. That is, after a certain dose, higher doses do not provide additional pain relief.

Fever occurs when something—infection or other causes—triggers the master body control in the brain, the thermoregulatory center in the hypothalamus, to reset core body temperature above the usual 98.6 degrees. Acetaminophen, as well as NSAIDs and aspirin, are thought to affect this regulatory center to decrease body temperature. Again, the mechanism is speculated to be the blocking of the COX enzyme.

Acetaminophen is literally in a drug class all its own, in contrast to the non-steroidal anti-inflammatory drugs, for which there are dozens of types. And it is for this reason—that it works but scientists don’t know how it works—that there is only one acetaminophen.

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Tylenol Extra Strength | 59 factors

81 points

Tylenol Extra Strength

Tylenol Extra Strength

Why is Tylenol Extra Strength better than others?

• Paracetamol?
  500mg vs 175. 77mg
• Tablets per pack?
  325 vs 44.37
• Dosage period?
  10 vs 7.75
• Elimination period?
  3.2h vs 3.42h
• Shelf life? Tylenol Extra Strength

  vs

  Tylenol Arthritis Pain

  Tylenol Extra Strength

  vs

  Tylenol Regular Strength

  Tylenol Extra Strength

  vs

  Midol Complete Caplets

  Tylenol Extra Strength

  vs

  Tylenol PM

  Tylenol Extra Strength

  vs

  Excedrin Migraine

  Tylenol Extra Strength

  vs

  Goody’s Extra Strength Headache Powder

  Tylenol Extra Strength

  vs

  Panadol Extra Advance

  Tylenol Extra Strength

  vs

  Excedrin Extra Strength

  Tylenol Extra Strength

  vs

  Advil Liqui-Gels

  Tylenol Extra Strength

  vs

  Anacin Maximum Strength Tablets

  Composition

  ibuprofen

  Ibuprofen is a non-steroidal anti-inflammatory drug. The analgesic effect of ibuprofen takes effect immediately, however, the anti-inflammatory effects can last up to a week.

  paracetamol

  Paracetamol (acetaminophen in the US) is classified as a mild analgesic. It suppresses the feeling of pain, but does not treat the cause.

  aspirin

  Aspirin can be used as an analgesic, antipyretic and anti-inflammatory agent.

  caffeine

  Research has shown that caffeine can increase the effectiveness of many analgesics, resulting in better, faster pain relief.

  codeine

  Codeine is an opiate used to treat mild to moderate pain. Opioids can change mood, sometimes resulting in a feeling of euphoria. It may be helpful in relieving pain, but addiction and withdrawal symptoms may occur.

  Has more than one active ingredient

  ✖Tylenol Extra Strength

  This product contains more than one active ingredient. These combinations usually complement each other, and sometimes one ingredient can enhance the effectiveness of another.

  naproxin

  Naproxen is an anti-inflammatory that can be used to treat a variety of pain symptoms.

  Effects

  Toothache

  ✔Tylenol Extra Strength

  Toothache is pain in and around the teeth and jaw, often caused by caries.

  Anti-Inflammatory

  ✖Tylenol Extra Strength

  Anti-inflammatory drugs are especially good for muscle and joint pain because they not only block the pain, but also treat the cause.

  Antipyretic (reduces body temperature)

  ✔Tylenol Extra Strength

  Antipyretic drugs help to reduce body temperature. This helps patients feel better, however, this is not always recommended as fever may be a natural defense against infections.

  Rheumatic pain

  ✔Tylenol Extra Strength

  Rheumatic pain is pain in the joints and connective tissue, most commonly caused by arthritis.

  Muscle pain

  ✔Tylenol Extra Strength

  Muscle pain can be caused by exercise or other stress, and infections such as the flu.

  Migraine

  ✔Tylenol Extra Strength

  Migraine is a very severe headache often accompanied by other symptoms such as flickering light, blind spots, tingling and sensitivity to light. Migraine sufferers often find it difficult to find adequate relief.

  Does not cause bloating

  ✖Tylenol Extra Strength

  Bloating, usually in the abdomen, causes discomfort. This is usually caused by a buildup of liquid or gas.

  Not associated with constipation

  ✖Tylenol Extra Strength

  Constipation means that there is difficulty with regular bowel movements.

  Naproxen not associated with heart risk

  ✔Tylenol Extra Strength

  Naproxen may increase your risk of heart attack or stroke, especially if you use it for a long period of time.

  Antipyresis in children

  Fedor Katasonov, a pediatrician at GMS Clinic, answered the most popular questions about what to do if a child has a fever in his Fediatry Telegram channel.

  How to measure temperature?

  I prefer a contact electronic thermometer, which is placed under the arm. After he squeaks, he must be held for another 3-4 minutes. After that, the readings will be approximately equal to those on a standard mercury thermometer. I do not recommend non-contact thermometers and measurements in the mouth and in the anus.

  Why measure temperature?

  The measurement is primarily of diagnostic value. We have a slightly different approach to conditions where the temperature is above or below the conditional limit of 38 degrees Celsius. Since most fevers in our latitudes resolve themselves within 3 days, in the absence of threatening symptoms, I recommend observation within 72 hours after the first rise in temperature above 38. If after this period it again rises above 38, a doctor’s examination is necessary to decide whether whether it is a protracted virus (and we continue to observe) or more aggressive intervention is required. Thus, we measure temperature to determine treatment tactics, but not to resolve the issue of fever reduction.

  How do I decide whether to lower the temperature?

  The answer is simple, regardless of the cause of the temperature. It does not matter if it is associated with an infection or a post-vaccination reaction, teething or other reasons.

  We lower the temperature when the child is unwell.

  There is nothing so useful in a rise in temperature that it can be tolerated, and nothing so harmful that it is necessary to take medicines when feeling normal. Therefore, when solving the issue of fever reduction, we look not at the thermometer, but at the child. If he is unwell, he is breathing heavily, lethargic, his muscles or his head hurt – you even lower 37.8. But if you can’t catch up with a child at 38.8 to pour medicine into him, then there is no need for medicine.

  How to lower the temperature?

  Since only parents of small children ask this question, I will not write about drugs for older children.

  Toddlers have only three home remedies to lower their temperature: the physical method, paracetamol (acetaminophen), and ibuprofen. If the child’s hands and feet are warm, they should be undressed, hung with wet towels, wiped with water at room temperature, wrapped in a wet handkerchief, or even put in a cool shower. To give or not to give at the same time the medicine is your choice. Depends on the level of your panic and the behavior of the child. Small children cool down perfectly on their own, sometimes it’s enough just to free them from their clothes. If the hands and feet are cold – vasospasm has begun – the physical method is not recommended, and only medicines remain.

  What formulation should I use?

  It’s not very important. Syrups with paracetamol (Panadol, Calpol, Tylenol, etc.) or ibuprofen (Nurofen, Advil) are easier to dose. Suppositories (Panadol, Efferalgan, Cefecon with paracetamol or Nurofen with ibuprofen) are good when the child cannot drink syrup (vomiting, allergic to additives). It seems to me that it is enough to have paracetamol suppositories at home for low temperatures (up to 39) and Nurofen syrup for more pronounced fevers.

  How to dose?

  The easiest way to dose Nurofen: syrup dose (ml) = 1/2 weight (kg). This is based on a single dose of ibuprofen 10 mg/kg.

  Paracetamol is dosed at 15 mg/kg. If you dose the most popular syrup – Panadol – you can multiply the child’s weight in kg by 0.625.

  A single dose can be given no more than 1 time in 4 hours, but preferably no more than 3 times a day.

  You should not use the dosage by age, which is often placed on the packaging of drugs. This is dangerous because children of the same age weigh very differently. Properly dose drugs by weight or body surface area, but not by age.

  What if an hour has passed and the temperature does not drop?

  • evaluate how you feel. If it has improved, the numbers are not important to us
  • even if the temperature has not dropped, the spasm must have gone, and you can connect the physical cooling method
  • if the need for antipyretics still remains, 1.