PPT 2 Flashcards
It is the quantitative amount administered or taken by a patient for the intended medicinal effect.
Dose
the amount of dose taken at one time
Single Dose
the amount of dose taken during the course of therapy.
Daily dose or Total dose
A daily dose may be subdivided and taken in ____, two or more umes per day depending on the characteristics of the drug and the illness.
divided doses
The schedule of dosing (e.g., four times per day for 10 days) is referred to as the:
Dosage regimen
Quantitatively, drug doses vary greatly among drug substances; some drugs have small doses, other drugs have relatively large doses.
The dose of a drug is based on its biochemical and pharmacologic activity, its physical and chemical properties, the dosage form used, the route of administration, and various patient factors.
It takes into account a patient’s ability to metabolize and eliminate drugs from the body due to impaired liver or renal function, which often necessitates a reduction in dosage
Pharmacokinetic dosing
It is the amount that ordinarily produces the medicinal effect intended in the adult patient.
Usual Adult Dose
the amount that ordinarily produces the medicinal effect intended in the infant or child patient.
Usual pediatric dose
It serve as a guide to physicians who may select to prescribe that dose initially or vary it depending on the assessed requirements of the particular patient.
The “usual” adult and pediatric doses of a drug
It indicates the quantitative range or amounts of the drug that may be prescribed within the guidelines of usual medical practice.
Usual dosage range
Many anticancer drugs are administered ____, usually for ______, with a rest period between dosing cycles to allow recovery from the toxic effects of the drugs.
cyclically
21 to 28 days
It is the amount that produces the desired intensity of effect in 50% of the individuals tested.
Median effective dose
It is the amount that produces toxic effects in 50% of the individuals tested.
Median toxic dose
An average blood serum concentration of a drug can be measured, and the minimum concentration determined that can be expected to produce the drug’s desired effects in a patient.
This concentration is referred to as the
Minimum Effective Concentration (MEC)
The base level of blood serum concentration that produces dose-related toxic effects is referred to as the:
Minimum Toxic Concentration (MTC)
Optimally, appropriate drug dosage should result in blood serum drug concentrations that are above the MEC and below the MTC for the period of time that drug effects are desired.
For certain drugs, a larger-than-usual initial dose may be required to achieve the desired blood drug level. This dose is referred to as:
Priming or Loading Dose
Similar in amount to usual doses, these are then administered according to the dosage regimen to sustain the desired drug blood levels or drug effects.
Subsequent maintenance doses
To achieve the desired drug blood level rapidly, the loading dose may be administered as an _____, whereas the subsequent maintenance doses may be administered in other forms, such as ___.
- injection or oral liquid
- tablets or capsules
There are certain instances in which low-dose therapy or high-dose therapy is prescribed for a particular patient. And for certain drugs, there may be different doses required depending on whether the use is for monotherapy, that is, as the primary drug treatment, or adjunctive therapy, that is, additional to or supportive of a different primary treatment.
Certain biologic or immunologic products, such as vaccines, may be administered in ____ to protect the patient from contracting a specific disease.
prophylactic doses
Other products, such as antitoxins, may be administered in _____ to counter a disease after exposure or contraction.
therapeutic doses
The doses of some biologic products, such as insulin, are expressed in ___, derived from biologic assay methods.
units of activity
Most pharmaceutical products are prepared on a large scale within the pharmaceutical manufacturing industry for distribution to institutional and community pharmacies.
These ____ products and dosage units are used in filling prescriptions and medication orders in the pharmacy.
prefabricated
On a smaller scale, many community and hospital pharmacists fill prescriptions and medication orders requiring ______–that is, the fabrication of a pharmaceutical product from individual ingredients, carefully weighed, measured, and mixed.
compounding
Pharmaceutical products may be prepared to contain one or more therapeutic agents. Products containing more than one therapeutic agent are termed:
combination products
One of the primary responsibilities of the pharmacist is to check doses specified in prescriptions based on a knowledge of the usual doses, usual dose ranges, and dosage regimens of the medicines prescribed.
If an unusual dose is noted, the pharmacist is ethically bound to consult the physician to make certain that the dose as written or interpreted is the dose intended and that it is suitable for the patient and condition being treated.
dosage forms contain _____, which provide the physical features, stability requirements, and aesthetic characteristics desired for optimal therapeutic effects.
pharmaceutical ingredients
With added pharmaceutical ingredients, the quantity of an active ingredient in a dosage form represents only a portion (often a small portion) of the total weight or volume of a product. For example, a tablet with 10 mg of drug actually could weigh many times that amount because of the added pharmaceutical ingredients.
In the institutional setting, doses are measured and administered by professional and paraprofessional personnel. A variety of measuring devices may be used, including ____ for oral liquids and ____ for parenteral medication.
calibrated cups
syringes and intravenous sets
In the home setting, the adult patient or a child’s parent generally measures and administers medication. Exceptions occur when home health care personnel are involved in a patient’s care.
Liquid dosage is usually measured in “household” terms, most commonly by the teaspoonful and tablespoonful. An oral dispenser finds use in administering calibrated quantities of liquid medication to children. For calculating dosages, useful equivalent measures are provided.
1 tsp - 1/6 fl.oz. - 5 mL
1 tbsp - 1/2 fl.oz. - 15 mL
In calculating doses, pharmacists and physicians accept a capacity of 5 mL for the teaspoonful and 15 mL for the tablespoonful.
It should be noted that the capacities of household teaspoons may vary from 3 to 7 mL and those of tablespoons may vary from 15 to 22
According to the United States Pharmacopeia, “For household purposes, an American Standard Teaspoon has been established by the American National Standards Institute as containing 4.93 ‡ 0.24 mL.
Through habit and tradition, the 3-symbol (fluidram) still is used by some physicians in the Signa portion of the prescription when indicating teasponful dosage.
The pharmacist may interpret this symbol as a teaspoonful in dispensing prefabricated manufacturers’ products called for on prescriptions and allow the patient to use the household teaspon.
It is used as a measure for small volumes of liquid medications.
- It does not represent a definite quantity, because this of different liquids vary greatly.
Drop (gtt)
The dropper, when held vertically,
in drops, each of which weighs between:
45 and 55 mg
the official dropper is
calibrated to deliver approximately:
20 drops of water per mL
It should be kept in mind, that few medicinal liquids have the same surface and flow characteristics as water, and therefore the size of drops varies materially from one liquid to another.
The drop should not be used as a measure for a specific liquid medication until the volume that the drop represents has been determined for that liquid.
It is the only one that should be used for the measurement of medicine. Most manufacturers include this along with their prepackaged medications for use by patients in measuring dosage.
calibrated dropper
A dropper may be calibrated by counting the drops of a liquid as they fall into a graduate until a measurable volume is obtained. The number of drops per unit volume is then established (eg. 20 drops/mL)
it is expressed in whatever denomination is chosen for measuring the given total quantity.
size of the dose
The administration of doses that are much smaller or much larger than the usual dose of a drug is referred to as
Low-Dose or High-Dose Therapy
The most common example of low-dose therapy is the use of aspirin in 81-mg amounts (rather than the usual dose of 325 mg) to lower the risk of heart attack and clot-related stroke.
Another example is the use of low-dose postmenopausal hormone therapy, in which doses often 50% smaller than standard doses are administered.
It is commonly associated with the chemotherapeutic treatment of cancer, in which there is an attempt, through increased dose intensity, to kill tumor cells.
Another example is the specialized use of high-dose progestin in the treatment of endometriosis.
High-dose therapy
Pharmacists must be aware of the use of high-dose therapies while remaining vigilant in protecting patients against unintended high doses and consequent drug overdose.
This circumstance most often occurs when a patient takes multiple medications (prescription and nonprescription) containing a common ingredient which, in total, may exceed a safe level.
inadvertent taking of an excessive quantity of a particular drug substance
Certain drugs have unique dosing regimens. Among them are:
chemotherapeutic agents
oral contraceptives.
DRUG INTERACTION IS VERY LIKELY; BuT MIGHT BE NOT PROVEN CINICALLY.
PROBABLE
DRUG INTERACTION MIGHT OCCUR AND SOME DATA MIGHT BE AVAILABLE.
suspected
DRUG INTERACTIM SUPPORTED BY WELL- PROVEN CLINICALLY STuDIES.
ESTABLISHED
DRUG INTERACTION THAT COULD OCCUR ; LIMITED DATA ARE AVAILABLE
possible
DRUG INTERACTION THAT IS DOUBTFUL; NO GOOD EVIDENCE OF AN ALTERED CLINICAL EFFECT IS AVAILABLE;
UNLIKELY
Adequate and well-controlled studies have failed to demonstrate a risk to the fetus in the first trimester of pregnancy (and there is no evidence of risk in later trimesters).
Category A
Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women.
Category B
Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite notential risks.
Category C
There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women desnite notential risks.
Category D
Studies in animals or humans have demonstrated fetal abnormalities and/or there is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience, and the risks involved in use of the drug in pregnant women clearly outweigh potential henefits
Category X
FDA has not classified the drug.
Category N
