disease such as an antibiotic destroying bacteria. Another physiological effect
can be the side effects that occur in the body such as nausea and vomiting or a
skin rash. A side effect is a physiologic effect that is not the intended action such
as the drowsiness that occurs when a patient takes an antihistamine. Some side
effects are beneficial while others are adverse effects that can be harmful to
a patient.
Healthcare providers must identify all known side effects of a drug and weigh
any adverse effects with the therapeutic effect before administering a drug.
Patients must also be informed about expected side effects and provided instruc-
tions about how to manage adverse side effects if at all possible.
For example, female patients are instructed to drink buttermilk and eat yogurt
when taking a broad-spectrum antibiotic. This counters a possible vaginal yeast
infection, which is a common adverse effect of broad-spectrum antibiotics.
Additionally, a female patient should be instructed to use other forms of birth
control when taking this medication because antibiotics lower the effectiveness
of birth control pills.
Many times patients will discontinue the use of a medication because the
side effects are so unpleasant. Antihypertensive medications (blood pressure
medicine) can cause side effects such as drowsiness or the inability to achieve
an erection in a male. Patients may decide that this effect is undesirable and
discontinue the use of the prescribed drug. Patients should be encouraged to
discuss any and all side effects with the provider. Many times, there are alter-
native medications that can be prescribed. Abruptly discontinuing the
use of a drug may not be in the best interest of a patient. Some drugs may be
gradually decreased in dose and frequency. Sometimes patients discontinue
taking a drug because they feel better, however, the condition being treated is
still present. Some examples of these types of medication are antibiotics and
antidepressants.Drug Safety
Drugs must undergo rigorous testing before being approved by the Food and
Drug Administration for use in humans. The initial testing is done with animals
to determine the toxicity of the drug. Acute toxicity is the dose that is lethal or
kills 50% of the laboratory animals tested. The testing is also done to determine
what symptoms are experienced by the animals and the time the symptoms appear.(^8) CHAPTER 1 An Inside Look at Pharmacology