drug actions
FACTORS AFFECTING DRUG ACTION
In drug administration, many factors affect the action of the medication. These factors also affect the dose to be administered. The usual adult dose of medication as listed in standard references, is based on the assumption that the adult weighs 150 pounds, but since the following variables influence the action of the medication, they also may alter the quantity of the drug necessary to produce the desired results
a. Weight. Heavy, burly clients require larger doses than weak, emaciated ones. The doses of many drugs are calculated on a weight basis; a specified number of grams or milligrams are administered per pound or kilogram of body weight.
b. Age. As a rule, the very young and the very old require less than the normal adult dose. As you recall from lesson 1, several formulas are available for estimating a child's dose when the average adult dose is known.
c. Sex. Females usually require smaller doses than males. Iron preparations and other hematinics are exceptions to this rule because of the blood lost by women during menstruation. In males the metabolism could be faster (testosterone is a CYP3A inductor), LD50 values may be higher–this is not always true
d. Race. Race can be a factor affecting drug action, since enzyme systems, body chemistry, and stature may vary.
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. Certain disease conditions also modify certain ,drug response e.g., hepatitis prolongs anaesthesia-with the ultra short acting barbiturates because the liver normally metabolizes these drugs.
In drug administration, many factors affect the action of the medication. These factors also affect the dose to be administered. The usual adult dose of medication as listed in standard references, is based on the assumption that the adult weighs 150 pounds, but since the following variables influence the action of the medication, they also may alter the quantity of the drug necessary to produce the desired results
a. Weight. Heavy, burly clients require larger doses than weak, emaciated ones. The doses of many drugs are calculated on a weight basis; a specified number of grams or milligrams are administered per pound or kilogram of body weight.
b. Age. As a rule, the very young and the very old require less than the normal adult dose. As you recall from lesson 1, several formulas are available for estimating a child's dose when the average adult dose is known.
c. Sex. Females usually require smaller doses than males. Iron preparations and other hematinics are exceptions to this rule because of the blood lost by women during menstruation. In males the metabolism could be faster (testosterone is a CYP3A inductor), LD50 values may be higher–this is not always true
d. Race. Race can be a factor affecting drug action, since enzyme systems, body chemistry, and stature may vary.
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. Certain disease conditions also modify certain ,drug response e.g., hepatitis prolongs anaesthesia-with the ultra short acting barbiturates because the liver normally metabolizes these drugs.