Ask the Pharmacist

Q: What can you tell me about fevers and how they should be treated?
 

A: Like many other medical symptoms, the thought process surrounding the treatment of fever has evolved over the years as we have come to a better understanding of its dangers and its role within our bodies.

A fever is defined as a higher-than-normal body temperature. Your temperature is controlled by a part of the brain called the hypothalamus which is essentially your body’s thermostat and acts to maintain your temperature. It works to warm you up (through shivering, narrowing the blood vessels closest to your skin or increasing your metabolism) or cool you down (through such body processes as sweating or opening up the blood vessels closest to the skin which increases the amount of blood there and allows the outside environment to cool the blood as it flows through).

While normal body temperature can depend upon the individual, age, time of day and even the weather, for most adults normal is defined as 37^oC (or 98.6^oF) when taken orally. That being said, this figure is actually an average of what your temperature normally is throughout the day. Your body’s actual temperature can change by as much as 0.6^oC (1^oF) in the course of a regular day depending upon many factors.

In general, as we discussed last week, a normal rectal or ear temperature is slightly higher than an oral one while an armpit temperature is slightly lower.

Fever occurs when your immune system is triggered by what we term pyrogens (which are simply fever-producing substances such as bacteria and viruses). Pyrogens usually come from outside the body and, in turn, stimulate the body to produce additional pyrogens which signal the hypothalamus to increase your temperature.

In general, you can say you have a fever when:
 

• Your oral temperature is 37.8^oC (100^oF) or higher
• Your rectal, ear or forehead temperature is 38^oC (100.4^oF) or higher
• Your armpit temperature is 37.2^oC (99⁰F) or higher
   

While fevers are an important sign that something is wrong within your body, a fever itself is not harmful and, in fact, can be very protective. It is not an illness but rather, a protective response designed to fight (usually) an infection. By elevating your temperature, bacteria and viral growth are suppressed while your immune system’s response is enhanced.

As such, fevers should be considered not only an alarm system that something has gone wrong within your body but also as a friend that will aid in your recovery (although it should be noted that lowering a fever through the use of medications does not seem to prolong illness based on numerous studies).

It, therefore, makes sense that not all fevers need to be treated although this goes contrary to many of our long-held beliefs as well as the training that many types of health care practitioners receive. Treating an elevated body temperature has not been shown to hasten recovery or to prevent adverse effects such as febrile seizures or brain damage, unfortunately.

Therefore, the goal of temperature-lowering therapy is to improve your comfort level, improve activity levels and, most importantly, reduce the loss of water induced by a fever that can eventually lead to dehydration. It is very important to note that you should never self-treat a child who is less than three months old. These cases should always be referred to a health care practitioner immediately (see last week’s article for when to send older kids and adults to the doctor as well).

When you do decide to treat due to discomfort, the two main drugs to turn to are acetaminophen (Tylenol) or ibuprofen (Advil, Motrin). Note that while Aspirin can lower a fever, it should never be used due to the risk of Reye syndrome. Both acetaminophen and ibuprofen are very effective and safe, although studies indicate that ibuprofen may be very slightly better at reducing temperature and also has the added advantage of working for a number of hours longer than acetaminophen.

For acetaminophen, the dose used should be 10-15 milligrams (mg) per kilogram (kg) given every four to six hours (with a maximum of five doses in a 24-hour period) and can be given at any age. Most adults (i.e. anyone over the age of 12) take from 325-1,000 mg in the same intervals mentioned above. Despite widespread concerns about acetaminophen’s effects on the liver, it is considered easily one of the safest drugs in the world when taken at its recommended dosages.

Ibuprofen is usually taken every six to eight hours and is given at a dose of five to 10 mg per kg for children ages six months to two years, with the actual dose depending upon the age and the elevation in the temperature (note, you should not exceed 40 mg per kg in a 24-hour period). Adults typically use 200-400 mg per dose, although higher amounts can be used.

Ibuprofen products should be avoided in those less than six months of age since infants have immature kidney function and ibuprofen use can lead to damage of this organ.

A frequent question we receive is whether the two drugs can be alternated when necessary (e.g. when a child appears quite uncomfortable three hours after the last dose of ibuprofen or acetaminophen). The alternating of therapies is considered safe and may well provide greater temperature reduction, as well improved comfort scores from its recipients. There is no evidence that this practice improves overall health outcomes and, as such, this should not routinely be done, but only when it is necessary.

As you can see, we are generally far less aggressive than we used to be when treating fevers, which has led to less medication use, a worthy goal indeed. The idea is to improve your comfort, not to “normalize” your temperature.

For more information about this or any other health-related questions, contact the pharmacists at Gordon Pharmasave, Your Health and Wellness Destination.