° Time
Medication must be given to the patient at the most opportune time dur-
ing the day to assure that the therapeutic effect is attained. Some drugs are
effective only if taken with meals while other medication cannot be taken
with meals. Likewise, certain drugs are more effective if taken at bedtime.° Food-drug interaction
Certain types of foods can adversely effect the drug’s therapeutic
effect by increasing absorption, delaying absorption, and even preventing
absorption of the medication. Furthermore, food may cause the patient to
experience an adverse reaction as in the case with phenelzine sulfate
(Nardil), which is an MAO monoamineoxidase inhibitor anti-depressant.
Nardil cannot be given with foods that use bacteria or molds in their prepa-
ration or for preservation of those that contain tyramine, such as cheese,
sour cream, beer, wine, figs, raisins,bananas, avocados, etc. The nurse
must assess if the drug has a contraindication with foodand educate the
patient about this food-drug interaction.° Drug-drug interaction
The nurse should be aware that the combination of drugs administered
to the patient may have a negative effect. Some drugs when administered
together might increase or decrease the therapeutic effectiveness of either or
both medications by competing for the same receptor sites in the body.
Furthermore, a combination of some medications produce toxicity or a fatal
condition such as anaphylaxis. Sometimes there is more than one provider
prescribing medications. The prescribers should be notified before medica-
tions are administered if there is a possibility of a drug-drug interaction.° Drug History, Tolerance, and the Cumulative Effect
Continued use of a medication might lessen the therapeutic effect of the
drug because the patient’s body becomes tolerant of the medication. The nurse
must assess the patient’s drug history and monitor the patient for signs and
symptoms that the drug is having a therapeutic effect. One such example
would be the absence of seizures if the patient is taking phenytoin (Dilantin),
an antiseizure medication. Another concern is the drug buildup in the patient’s
body. The patient may be unable to metabolize and excrete the medication as
fast as new doses are administered. The result is a cumulative effect that can
result in toxicity. The patient should be monitored for signs of drug build-up.
For example, ataxia (muscular incoordination), nystagmus (rhythmic oscilla-
tion of eyes), and double vision are signs of toxic levels of Dilantin.(^86) CHAPTER 5 Medication Administration