chapter 8

Question 1

It is the quantitative amount administered or taken by a patient for the intended medicine effect

Answer 1

dose of a drug

Question 2

It is the amount taken at one time.

Answer 2

Single dose

Question 3

It is the amount taken during the course of therapy. A daily dose may be subdivided and taken in divided doses.

Answer 3

Daily dose or Total dose

Question 4

These are two or more times per day depending on the characteristics of the drug and the illness.

Answer 4

Divided doses

Question 5

It is the schedule of dosing (i.e., four times per day for 10 days).

Answer 5

Dosage regimen

Question 6

The dose of a drug si based on its biochemical and pharmacologic activity, its physical and chemical properties, the dosage form used, the route of administration and various patient factors.

Question 7

The dose of a drug for a particular patient may be determined ni part on the basis of the patients’ age, weight, body surface area, general physical health, liver and kidney functions, and the severity of the illness being treated

Question 8

He devised a five-step approach in dealing with drug calculations.

Answer 8

Hutton

Question 9

Some drugs are not chemically stable in solution and so are supplied as dry powders for reconstitution just before use. Many of these are antibiotics, but there is also a range of chemotherapeutic agents used in cancer treatment

Question 10

An oral antibiotic for reconstitution comes as a powder in a bottle with sufficient space to add the water.

The powder itself wil remain stable for up to ___ when dry. When reconstituted, a shelf life of ____ is normal, depending on whether it is refrigerated or not.

Answer 10

two years

10 to 14 days

Question 11

1 kg = 2.2 lbs

Question 12

Certain situations would require to calculate doses based on body weight (mg/kg) or in terms of a patient’s body surface area (mg/m’).

Using body surface area (BSA) estimates is more accurate than using body weight, since many physical phenomena are more closely related to the BSA.

This particularly applies to cytotoxics and other drugs that require an accurate individual dose.

Question 13

For many clinical purposes, it is a better indicator of metabolic mass than body weight because it is less affected by abnormal adipose mass.

Answer 13

Body Surface Area

Question 14

It is usually divided by the BSA to gain an appreciation of the true required glomerular filtration rate (GFR).

Answer 14

Renal clearance

Question 15

It is often dosed according to the patient’s BSA.

Answer 15

Chemotherapy

Question 16

It can also be expressed in terms of BSA for calculating maintenance doses or to compare high dose use with maintenance requirement.

Answer 16

Glucocorticoid dosing

Question 17

A common method used to identify BSA

Answer 17

Nomogram

Question 18

A nomogram typically has three columns:

Answer 18

• height based in both centimeters and inches;
• body surface area in m2; and
• weight based in both kilograms and pounds

Question 19

The formula derived by Mosteller (1987) combines an accurate BS calculation with ease of use and has been validated for both children and adults. This formula can be used on a handheld calculator:

Answer 19

m2 = height (cm) x weight (kg) / 3,600

Question 20

Take note that for most patients the _____ is the weight to be considered for dosing drugs.

Answer 20

actual (total) body weight (ABW or TBW)

Question 21

BSA rule:

Answer 21

BSA of child (m2)/1.73 m2 x adult dose

Question 22

They are generally classified as persons over 60 years of age.

Answer 22

Geriatric patients

Question 23

Some patients may have geriatric symptoms at 50 years of age or even younger. As we age, our physiologic functions start to decline.

Question 24

These are major concerns when dosing medications in elderly patients. They both affect the absorption and elimination of medications.

Answer 24

Kidney and liver functions

Question 25

It may affect drug/dose effectiveness.

Answer 25

Concomitant drug therapy

Question 26

It is a major consideration in drug dosing in the elderly because its reduced function results in reduced drug elimination.

Answer 26

Kidney function

Question 27

It diminishes nearly 1% per year after age 30, making the cumulative decline in most persons 60 to 70 years of age about 30% to 40%,

Answer 27

Renal blood flow

Question 28

It is derived from metabolism of creatinine in skeletal muscles and from dietary meat and releases into the circulation at a relatively constant rate with a stable plasma concentration and freely filtered across the glomerulus

Answer 28

Creatinine

Question 29

They are classified as persons under the age of 18

Answer 29

Pediatric patients

Question 30

Age Breakdown of Pediatric Patients

Answer 30

Neonatal - birth to 1 month
Infant - 1 month to 2 years
Child - 2 years to 12 years
Adolescent - 13 years to 17 years

Question 31

These are medications that are used for cancer.

They are very potent, hazardous chemicals that cause cell death.

Because these agents are so hazardous, dosing them correctly is critical. These medications are normally dosed based on BSA and take into consideration kidney (renal) function

Answer 31

Chemotherapy agents

Question 32

It is used with more than a single treatment modality included in a patient’s treatment plan (e.g, radiation and chemotherapy) (14). It often include two-agent regimens, three-agent regimens, and four-agent regimens

Answer 32

combination therapy

Question 33

The major categories of chemotherapeutic agents include:

Answer 33

alkylating agents
antimetabolites
plant alkaloids
antitumor antibiotics
steroid hormones

Question 34

The major categories of chemotherapeutic agents include:

Answer 34

alkylating agents
antimetabolites
plant alkaloids
antitumor antibiotics
steroid hormones

Question 35

Chemotherapeutic agents most often are administered orally, by intravenous injection, or by continuous intravenous infusion;

Answer 35

however, other routes of administration are used as required, including intra-arterial (artery), intrathecal (spinal column), or intramuscular injection, or administration to a specific site, such as the lungs (intrapleural), the abdomen (intraperitoneal), the skin (topical), or others

Question 36

For systemic action, chemotherapeutic agents are usually dosed based either on body weight or body surface area.