e. Temperament. The high-strung, nervous, always-busy type of individual
requires smaller amounts of stimulants but larger amounts of sedatives than the
phlegmatic (dull, apathetic) individual.
f. Climate. Cathartics seem to be effective in smaller doses in warm climates
than in cold.
g. Occupation. Men who work outdoors and who engage in strenuous,
physical activity usually require larger doses than those who are engaged in sedentary
or indoor work.
h. Disease. Some pathological conditions require changes in dosage. People
in extreme pain need more analgesic and sedative drugs than those suffering only mild
pain. The extremely weak or debilitated client may require smaller doses of some
i. Tolerance. The therapeutic effects of some medications are lessened in
individuals after prolonged use. Thus, a person who has used such a drug for a long
time needs larger doses than he did when he first began to take it in order to realize the
same therapeutic effects from it. This is called tolerance. Users of opium, morphine,
cocaine, amphetamines, and barbiturates fall into this category. Cross-tolerance
develops when the use of one drug causes a tolerance to another. Alcoholics,
barbiturate habitues, and narcotic addicts develop a cross-tolerance to sedatives and
anesthetics. These individuals require very large amounts of anesthetics before
surgical anesthesia can be attained.
j. Mode of Administration. Generally, drugs given parenterally are used in
smaller quantities and those given rectally are used in greater quantities than the usual
k. Frequency of Administration. Drugs given at frequent intervals are
administered in smaller doses than those given at wide intervals.
l. Time of Administration. Some drugs given by the oral route are absorbed
more rapidly before a meal (on an empty stomach) than they would be if they were
administered immediately after a meal.
m. The Drug. Many factors of the drug itself can influence its action. They may
alter its potency, making some preparations weaker and others stronger. The form of a
drug, that is, solution, powder, or suspension, may alter the amount of the drug
necessary and the effects derived from it.
n. Additive Effect. If two drugs exhibit the same overt effect and their
combined effects are equal to the sum of their individual effects, they are additive.