1. Life Span Consideration
Chapter 7

2. Drug Absorption Absorption:
Process by which a drug is transferred from its site of body entry to circulating body fluids (blood, lymph) for distribution

3. Drugs applied to the Skin
Absorption of drugs applied to the skin (topical) is usually effective in infants
Outer layer of skin not fully developed
Skin is more fully hydrated
Enhanced with plastic-coated diapers
Plastic increase hydration of the skin
Inflammation of skin also increases the amount of drug absorbed
Ex. Diaper Rash
Skin absorption in older patient is often hard to predict
Drier skin
Wrinkled skin
Decreased number of hair follicles
Decreased cardiac output
Decreases the amount of blood flow to tissues

4. Drugs Given Orally Most drugs are administered orally
Some tablets and capsules are too large for children and older patients
With permission some tablets can be crushed & mixed with food
Some tablets cannot be crushed:
Timed-release
Enteric-coated
Sublingual
Liquids can also be ordered

5. Oral Medications Factors to consider: Teeth: Saliva flow:
Do not give chewable tablets to anyone lacking teeth or loose teeth
Saliva flow:
Lessens with age

6. Gastrointestinal Absorption
GI absorption of drugs is influenced by disease processes other factors including:
Gastric pH:
Gastric emptying
Motility of the GI tract
Blood flow

7. Drug Distribution Distribution:
Mode in which drugs are transported by circulating body fluids to the sites of action (receptors) and to the sites of metabolism and excretion.
Most drugs are transported:
Dissolved in the circulating body water (blood)
Bound to plasma proteins with the blood

8. Drug Metabolism Metabolism:
Process by which the body inactivates drugs
Enzymes are factors in drug metabolism
Enzymes:
Substances produced by body cells
Enzymes break down glucose and other nutrients to release energy for cellular work.
Enzyme systems in the liver provide the major pathway for drug metabolism
Liver weight, number of functioning liver cells and liver blood flow decrease with age, therefore metabolism is slower in elderly
Other factors that may affect metabolism include:
Genetics, smoking, diet, gender, liver disease, other medications

9. Drug Excretion Excretion: Elimination of a drug from the body
Metabolites of drugs, and sometimes the drug itself, are eventually excreted from the body
Excreted mainly through urine and feces
Minor routes of excretion include:
Skin
Lungs
Saliva
Breast Milk

10. Therapeutic Drug Monitoring
Measurement of a drug’s concentration in body fluids
Completed in order to determine the drug dosage and the blood level of the drug in relation

11. Assisting with the Nursing Process
Vital signs & urinary output are used to plan dosages and monitor the effects of drug therapy
Children:
Great risk of complications as bodies & organs are developing
Elderly:
Great risk for drug interactions and/or drug toxicity
Assist through the use of drug organizers, destroying old prescriptions, and breaking/crushing large tablets if allowable
Pregnancy / Breast Feeding:
Risk of injuring developing fetus