OUTDATED MEDICINES
If your physician has prescribed a drug
for you and instructs you to discontinue its use before the supply is all gone
don't save what is left over for another time. Discard it. It may seem like a
waste to throw away expensive medication; actually, it is an important safety
precaution. Some drugs lose potency with time; some gain potency. Either way,
their use after a lapse of time can be dangerous.
Moreover, it has become clear
that some drugs, in the process of aging, not only change in potency; they
undergo marked chemical changes that can make them dangerous. Not long ago, for
example, physicians at three New York hospitals reported on several patients
who had suddenly experienced nausea and vomiting and then developed symptoms
like those of diabetes. The trouble in each case was traced to chemical
deterioration of an antibiotic, a tetracycline, taken long after it should have
been thrown away.
DRUG INTERACTIONS
when one medication is being used, the
addition of another sometimes can be helpful but sometimes can be harmful. When
two agents used in concert do not harmonize, the interaction or interference
can cause trouble. Moreover, even effects on dosage requirements must be
considered when two or more medicines are being used. Recently, for example, a
patient who had had a heart attack and recovered from it was released from the
hospital.
Ten days later, an alarming condition developed. While in the
hospital the patient had received an anticoagulant medication as part of
treatment-a compound aimed at preventing clotting. At home, he continued as
directed to take the same compound in the same dosage. But now the drug was
thinning.
The blood too much
Something had changed. It had indeed: in the
hospital, the patient had been given phenobarbital upon retiring. The sedative,
in the course of its activity in the body, had stimulated certain liver
chemicals which broke down the anticoagulant faster. At home, without the
phenobarbital, the anticoagulant activity continued longer and was more potent.
In effect, without the sedative, the patient was getting an overdose of.
The anti-coagulant
The
matter, once understood, was quickly adjusted. But it illustrates what is
coming to be virtually a new science in medicine, concerned with understanding
and taking into account inter- actions between medicines. This, of course, is
not the place to go into complex technical details.
But as indications of how
important interaction can be, here are some recent findings: When a patient is
taking aspirin, addition of an anticoagulant drug may lead to bleeding. If a
patient is receiving a medication such as amitriptyline for mental depression
and is also given guanethidine for high blood pressure, the antihypertensive
activity of the latter is lost.
