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HEALTH
PRESCRIPTION DRUGS
SOME THINGS YOU SHOULD KNOW ABOUT
PRESCRIPTION DRUGS
You see your doctor, get a prescription, have it filled
and take the medicine. Isn't that all you need to know
about prescription drugs? No! Drugs are powerful
chemicals. Along with their benefits, they also have a
potential for harm.
ADVERSE REACTIONS
Some drugs can cause side effects (adverse reactions).
Usually these are mild a slight rash, mild headache,
nausea or drowsiness; sometimes they are severe -prolonged
vomiting, bleeding, marked weakness or
impaired vision or hearing.
These are warning signals that the drug is causing
problems. When a reaction is unexpected or severe you
should contact your doctor immediately.
Not everyone reacts the same way to medication. One
person may experience a reaction to a certain drug,
while another person may have no problems at all.
DRUG TO DRUG INTERACTION
Two or more drugs, taken at the same time can interact
and effect the way one or the other behaves in the body.
For example, an antacid will cause a blood thinning
(anti-coagulant i.e. Coumadin or heparin) drug to be
absorbed too slowly, while aspirin greatly increases the
blood-thinning effect of such drugs.
Two drugs with the same effect when taken together can
sometimes have an impact greater than would be
expected. This is call potentiation. Potentiation can be
helpful, as when the antibiotic Bactrim or Septra is used
to boost the effect of another antibiotc Sulfam
ethoxazole, in combatting certain infections.
Potentiation also can be dangerous, particularly when
several central nervous system depressing drugs are
involved. Even non-prescription drugs such as anti
histamines that are often used to fight colds, can
increase the sedative effect of tranquilizers, anesthetics,
barbiturates and some pain killers.
FOOD AND DRUG INTERACTIONS
Food can interact with drugs, making their work faster
of slower or even preventing them from working at all.
Here are some examples: Fatty foods, eaten before
taking the anti-fungal drug Griseofulvin, can cause blood
levels of the drug to rise markedly. Calcium in dairy
products inhibits the absorption of Tetracycline, a widely
used antibiotic. Citrus fruits or juices containing
ascorbic acid speeds the absorption of iron from iron
supplements. Soda pop, fruit and vegetable juices with
high acid contents (such as grape, apple, orange or
tomato) cause some drugs to dissolve in the stomach
instead of the intestines where they can be more readily
absorbed.
Large amounts of liver and leafy vegetables may hinder
the effectiveness of anti-coagulants because vitamin K in
these foods promotes blood clotting.
The most hazardous food-drug interaction is that of
drugs sometimes prescribed for severe depression or
high blood pressure and foods containing the substance
tryamine. The drugs involved contain monoanmine
oxidase (MAO) inhibitors. The foods involved include
aged cheese, Chianti wine, pickled herring, fermented
sausage, yogurt, sour cream, chicken liver, broad beans,
canned figs, bananas, avocados and foods prepared with
tenderizers. Mixing these foods with an MAO inhibitor
drug can raise the blood pressure to dangerous levels.
The food-drug interaction can go the other way. Oral
contraceptives, for instance, are known to lower levels of
folic acid, a member of the vitamin B family, and
vitamin B6 although the depletion is usually not serious
enough to cause symptoms. Women who take birth
control pills would be wise to include dark green leafy
vegetables in their diet. Chronic use of antacids contain
ing aluminum can cause phosphate depletion, leading to
weakness, malaise and loss of appetite.
DRUGS AND ALCOHOL
Chronic use of alcohol can cause changes in the liver
that speed up the metabolism of some drugs, such as
anti-convulsants, anti-coagulants and diabetes drugs.
They become less effective because they do not stay in
the body long enough.
Prolonged alcohol abuse can also damage the liver so
that it is less able to metabolize or process certain drugs.
In that case, the drugs stay in the body too long. This is
particularly serious when the drugs are phenothiazines
(anti-psychotic drugs), which can cause further liver
damage.
Alcohol is a central nervous system (CNS) depressant.
Alcohol taken along with another CNS depressant drug
can affect performance skills, judgement and alertness.
If the mixture includes overdoses or barbiturates,
Valium or Darvon, the result may be fatal.
A person who has developed a tolerance to the sedative
effects of alcohol may need larger doses of tranquilizers
or sleeping pills to get the desired effect. This can lead
to an overdose without the person being aware of it.
Similarly, alcoholics and patients with alcohol in their
system need larger amounts of anesthetics to induce
sleep. Once such patient is "under", his sleep is deeper
and lasts longer.
DRUGS AND SMOKING
Women on birth control pills who smoke have an
increased risk of heart attack, stoke and other circula
tory diseases.
Nicotine and other tobacco constituents speed up the
metabolism of theophylline, an asthma drug, and
pentazocine, a pain-killer, and to a lesser extent, certain
tranquilizers, analgesics and anti-depressants. Thus,
smokers may need larger than normal doses of these
drugs. When they stop smoking, dosage of these drugs
may have to be changed. ;
Smoking also can affect certain diagnostic tests, such as
red and white blood cell counts and blood clotting time
determinations.
DRUGS AND LABORATORY TESTS
Drugs can affect the results clinical laboratory tests. For
example, excess use of laxatives can affect tests to
determine calcium or bone metabolism. Penicillin can
result in false readings of protein in the urine, a sign of
kidney disease. Large doses of vitamin C can produce
false results in a urinary glucose test for diabetes.
WHAT YOU SHOULD ASK YOUR DOCTOR
To get the most out of your medicine, you should ask '
you doctor:
1. What is the name of the medicine? Write it down so
you won't forget.
2. What is the medicine supposed to do? (Make the
pain go away? Get to the cause of the pain? Reduce
fever? Lower blood pressure? Cure infection?)
3. What side effects might occur?
4. How should you take the medicine? Does "three
times a day" mean morning, noon and night? Should
you take it before meals, with meals, or after meals? If
the directions say "every sue hours" do you have to get
up during the night to take the medicine.
5. How long should you take the medicine? If you stop
just because you feel good, the symptoms and the
disease may recur.
6. Are there other medicines you should not take while
you are taking this one?
7. Are there any foods or beverages you should avoid?
8. Should you avoid alcoholic beverages while taking the
drug?
9. Can the prescription be refilled without an appoint
ment or does the doctor need to see you again?
WHAT'S ON YOUR PRESCRIPTION
The first word on the prescription is the name of the
drug. Next is the dosage form (liquid, capsules, tablets)
and the strength (such as 250 mg, or milligrams). Next
is the amount you will get (15 capsules, 5 fluid ounces),
followed by the directions for use; these are often
abbreviations of latin words. For instance, ter in die,
written as t.i.d. means three times a day. The pharma
cist will translate this information on the label of the
j medicine container. The prescription form will also
' indicate how many times the prescription can be refilled.
It's a good idea to check your prescription before you
leave the doctor's office. If there is anything you don't
understand, ask about it.
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