Sometimes it seems like there are more medicines than there are
diseases. Some medications can be bought over the counter at
pharmacies or other stores. Others require a doctor's
prescription. A few medicines are available only in hospitals.
Medicines can cure, stop, or prevent disease; ease symptoms; or
help in the diagnosis of certain illnesses.
What Are Medicines?
Medicines are chemicals or compounds used to prevent or treat
diseases and the symptoms you might have as a result of those
diseases. During the past century, advances in medications have
enabled doctors to cure many diseases and save lives.
These days, medicines come from a variety of sources. Many have
been developed from substances found in nature, and even today many
are extracted from plants. For example, one medicine that is used
to treat cancer comes from the Pacific yew tree.
Some medicines are produced in a laboratory by mixing together a
number of chemicals; others, like penicillin, are a byproduct of
organisms such as fungus. And a few medicines are even biologically
engineered by inserting genes into bacteria that make them produce
the desired substance.
When we think about taking medications, we often think of pills.
The truth is, there are many ways in which medications can be
delivered, such as:
- liquids that are swallowed (like cough syrup)
- drops that are put into ears or eyes
- creams, gels, or ointments that are rubbed onto the skin
- inhalers (like nasal sprays or asthma inhalers)
- patches that are stuck to skin (called transdermal
patches)
- tablets that are placed under the tongue (called sublingual
medicines; the medication is absorbed into blood vessels and
enters the bloodstream)
- shots
No medicine can be sold for use unless it has first been
approved by the U.S. Food and Drug Administration (FDA). The
manufacturers of the medication perform tests on all new medicines
and send the results to the FDA.
The FDA allows new medicines to be used only if they work and if
they are safe enough. When a medicine's benefits outweigh its
known risks, the FDA usually approves the sale of the drug. The FDA
can withdraw a medication from the market at any time if it later
is found to cause harmful side effects.
Different Types of Medicines
Medicines act in a variety of ways. Some can cure an illness by
killing or halting the spread of invading germs, such as bacteria
and viruses. Others are used to treat cancer by killing cells as
they divide or preventing them from multiplying. Some drugs simply
replace missing substances or correct abnormally low levels of
natural body chemicals such as certain hormones or vitamins.
Medicines can even affect parts of the nervous system that control
a particular body process.
Nearly everyone has taken an antibiotic. This type of medicine
fights bacterial infections. Your doctor may prescribe an
antibiotic for things like strep throat or an ear infection. These
medicines work either by killing bacteria or halting their
multiplication so that the body's immune system can fight off
the infection.
Sometimes a part of the body can't produce enough of a
certain chemical. That can also make you sick. Someone with
insulin-dependent diabetes, for instance, has a pancreas that
can't produce enough insulin. Some people have a low production
of thyroid hormone, which helps control how the body uses energy.
In each case, doctors can prescribe medicines to replace the
missing chemical.
Some medicines treat symptoms but can't cure the illness
that causes the symptoms. (A symptom is anything you feel while
you're sick, such as a cough or nausea.) So taking a lozenge
may soothe a sore throat, but it won't kill that nasty strep
bacteria.
Certain medicines are designed to relieve pain. If you pull a
muscle, your doctor might tell you to take ibuprofen or
acetaminophen. These analgesics don't get rid of the
source of the pain - your muscle will still be pulled. What they do
is block the pathways that transmit pain signals from the injured
or irritated body part to the brain (in other words, they affect
the way the brain reads the pain signal) so that you don't hurt
as much.
As people get older, they sometimes develop chronic or long-term
conditions. Medicines can help control certain conditions like high
blood pressure or high cholesterol. These drugs don't fix the
basic problem, but they can help prevent some of the body-damaging
effects of the disease or condition over time.
Among the most important medicines are immunizations. These keep
people from getting sick in the first place by immunizing, or
protecting, the body against certain infectious diseases. Vaccines
contain parts or products of infectious organisms or whole germs
that have been modified or killed. When a vaccine is given, it
primes the body's immune system to fight off infection by that
germ.
Most immunizations that prevent you from catching diseases like
measles, whooping cough, and chickenpox are given by injection. No
one thinks shots are fun. But when your friends get the flu and you
don't, thanks to your flu shot, that injection isn't so
bad.
Although some medications require a prescription, some are
available in stores. For example, many medications for pain, fever,
cough, or allergies can be purchased without a prescription. But
just because a medicine is available over-the-counter (OTC), that
doesn't mean it's free of side effects. Take
over-the-counter medicines with the same caution as those that are
prescribed by your doctor.
Taking Medicines
No matter what type of medicine your doctor prescribes, it's
always important to be safe and follow some basic rules:
- If you feel worse after taking a medicine, tell your doctor
right away.
- Double-check that you have the right medicine. If you get the
same prescription filled more than once, check that it's the
same shape, size, and color as the last time. If not, be sure to
ask the pharmacist about it.
- Read the label and follow directions. Ask if you have
questions.
- Take medicines as prescribed. If the instructions say take
one tablet four times a day, don't take two tablets twice a
day. It's not the same.
- Ask if the medicine is likely to affect everyday tasks such
as driving or concentrating in school.
- Don't take more medication than is recommended. It
won't make you heal faster or feel better quicker. In fact,
an overdose of medication can make you sick.
- Always follow your doctor's or pharmacist's
instructions. For instance, he or she may tell you to take a
medicine with food to help lessen the stomach upset it may cause
or take the medicine on an empty stomach so as not to interfere
with the medicine's absorption into your body.
- Never share prescription medicine with anyone else, even if
that person has the same thing as you do. Today's medications
are very complex, and the dosages tend to be precisely prescribed
for each person's needs. Either under-dosing or overdosing
can be harmful. Additionally, someone else's body may react
differently to the same medication - for example, if they have an
allergy to one of the components of the medication.
- If you're already taking a medication but also want to
take something you can buy over-the-counter, ask the pharmacist.
There could be a bad interaction between the medications.
- Remember that drinking alcohol can dramatically worsen the
side effects of many medications.
- Always tell your doctor and pharmacist if you're taking
any other medicines or any herbal supplements so that he or she
can check for any interactions between the medications.
- Even if you get sick with what you think is the same old
thing, don't decide on your own that you know what's
wrong and take some leftover medicine. Taking that medicine for a
different disease may not work - and it can even be harmful. Talk
to your doctor first.
- Take antibiotics for the full time prescribed, even if you
start to be feel better, so that all the germs are killed and the
infection doesn't bounce back.
- Keep medicines in their original labeled containers, if
possible.
- Don't use medicine that has expired, especially
prescription medicine.
- Medicines should not be stored in your bathroom because heat
and humidity can affect the potency of the drug. Most medicines
should be kept at room temperature and away from sunlight. Some
must be refrigerated. Check with your pharmacist or doctor if you
aren't sure.
- Make sure all medicines are stored safely and out of the
reach of younger brothers or sisters and pets.
- If you have any allergies, tell your doctor and pharmacist
before they start you on a new medicine.
- If you get a rash, start itching, or have trouble breathing
after starting a medication, tell your parents immediately.
Breathing difficulty, breaking out in hives, or suddenly
developing swelling of the tongue, lips, face, or other body
parts may be signs of a severe allergic reaction - get emergency
medical care right away.
Taking medicines may feel like a hassle sometimes. But medicines
are the most effective treatments available for many illnesses. If
you ever have any questions about what a medicine does or how you
should take it, talk with your doctor or the pharmacist.
Reviewed by:
Larissa Hirsch, MD
Date reviewed: November 2006
Originally reviewed by:
James R. Hildebrand III, PharmD
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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