Side Effects of Drugs
All drugs has side effects. Some drugs makes you sleepy, others
- like for example antidepressants - can give you a headache.
Other remedies can make your heart beat fast. Why do drugs have
side effects?
Our bodies are complex structures, built from chemicals and to
function smoothly it has to be regulated. Chemicals like for
instance hormones, enzymes and other molecular messengers
normally make these adjustments. The purpose of medicines are
often to take the place of one of the body's regulating
chemicals, because of a disease that has been brought out of
balance and readjust this. And this is what any successful
medicine or drug treatment actually does.
To understand why medicine produces side effects, we have to pay
attention to the following: 1. Our body often uses the same
chemical to regulate more than one process. What this means is
that a medicine may retune not only the desired target but also
others that don't need readjustment. Let's use prednisone as an
example; this drug gets rid of inflammation, but it also causes
thinning of bones.
2. Unfortunately, drugs are not always as selective as we would
like them to be. A consequence of this is that the medicine may
alter a number of unrelated processes at the same time. The
antidepressant amitriptyline can help depression but it can also
lower blood pressure by affecting norepinephrine receptors,
cause blurred vision, dry mouth and constipation by blocking
acetylcholine receptors and even induce sleepiness and weight
gain by binding to histamine receptors.
3. It is also a fact that two people taking the same medicine
can have very different experiences. One person may have severe
or troublesome side effects that make the medicine intolerable
(like nausea during the first weeks of taking Effexor), while
another person hardly notice any side effects at all. This is
the reason of the long list of possible side effects that is
enclosed in the drug box.
Side effects may be rare or common, serious or simply annoying.
Doctors are required to assess the risk of side effects versus
the expected benefit of any medication. Statistically most
doctors do a good job, so if you have a doctor you feel you can
trust in general, there is no need for distrusting his or her
abilities to figure out which medication is best for you.