Drugs and the Body discusses the pharmacokinetics and pharmacodynamics of how drugs act on the body. Pharmacokinetics describes the absorption, distribution, metabolism and excretion of drugs in the body. Pharmacodynamics examines how drugs produce their effects by interacting with receptor sites or replacing missing chemicals. Nursing management of drug administration involves ensuring the "rights" of giving the right drug to the right patient via the right route and dose. The nursing process - which includes assessment, nursing diagnosis, planning, interventions and evaluation - is used to properly manage a patient's drug therapy.

1. Drugs and the Body
Nhelia B. Perez, RN, MSN
PCU - MJCN

3. Pharmacokinetics

4. Phases of Pharmacokinetic
• Absorption
- maybe reduced if the villi is
decreased (disease, drug
effect, removal of small
intestines)
- may be passive (diffusion)
or active carrier).

5. Distribution
-blood flow, drug’s
affinity to the tissue
protein binding effect,
drug volume.

6. Metabolism
• Hepatic role
• Liver diseases
• Half life

7. Excretion
• Kidneys
• Kidney diseases

8. PHARMACODYNAMICS
• DRUG ACTIONS
• To replace or act as substitutes for
missing chemicals.
• To increase or stimulate certain cellular
activities.
• To depress or slow cellular activities.
• To interfere with the functioning of foreign
cells, such as invading microorganisms or
neoplasms.

9. RECEPTOR SITES
• React with certain chemicals to cause
an effect within the cell.
• Some drugs directly interact with
receptor sites to cause the same
activity that natural chemicals would
cause at the site. (agonist)
• Other drugs prevent the breakdown of
natural chemicals that are stimulating
the receptor sites.

10. • Some drugs react with receptor
sites to block normal
stimulation, producing no
effect.
• Other drugs react with specific
receptor sites on a cell and by
reacting there, prevent the
reaction of another chemical
with a different receptor site on
that cell.

12. PHARMACODYNAMICS
• Critical Concentration
• Loading Dose
• Dynamic Equilibrium
• Absorption
• Administration
• First pass effect
• Distribution
• Protein binding
• Blood-Brain barrier

13. • Placenta and Breast Milk
• Biotransformation
• Excretion
• Half-Life

14. FACTORS INFLUENCING DRUG EFFECTS
• Weight
• Age
• Gender
• Physiological factors
• Pathological factors
• Genetic factors
• Immunological factors
• Psychological factors
• Environmental factors

15. • Tolerance
• Cumulation
• Drug-drug or drug-alternative
therapy interactions
• Drug laboratory test interactions

16. Adverse
Effects of
Drugs

17. TOXIC EFFECTS OF
DRUGS

18. SIDE EFFECTS
• Problems that occur when
treatment goes beyond the
desired effect. Or problems that
occur in addition to the desired
therapeutic effect.

19. ADVERSE EFFECTS
• the Drug may have other effects on the body besides
the therapeutic effect.
•The patient is sensitive to the drug being given.
•The drug’s action on the body causes other responses
that are undesirable or unpleasant.
•The patient is taking too much or too little of the drug,
leading to adverse effects

20. Types of Adverse Effects
• Primary actions
– Overdose: extension of the
desired effect
• Secondary actions
– Undesired effects produced in
addition to the pharmacologic
effect
• Hypersensitivity reactions
– Excessive response to the
primary or secondary effect of the
drug

21. Drug Allergy
• Can occur when the body forms
antibodies to a particular drug.
• It may be anaphylactic,
cytotoxic, serum sickness or
delayed allergic reaction.

22. Idiosyncratic Reactions
• also known as type B reactions,
are drug reactions which occur
rarely and unpredictably amongst
the population.
• They frequently occur with exposure
to new drugs, as they have not been
fully tested and the full range of
possible side effects have not been
discovered; they may also be listed
as an adverse drug reaction with a
drug, but be extremely rare.

23. Teratogenic Effect
• These effects are classed as deterministic,
which means that the severity as well as
incidence is related to dose.
• The combined consequences of
consuming a harmful substance, such as
alcohol, on a developing fetus; may
manifest itself as growth deficiency and/or
mental retardation; fetal alcohol syndrome
is an example.

24. LET’S TAKE
A
BREAK!!!

25. Nursing
Management

26. RIGHTS IN DRUG ADMINISTRATION
• Right Patient
• Right Route
• Right Drug
• Right Frequency
• Right Dose

27. • Right Approach
• Right Assessment
• Right to refuse
• Right Education
• Right Evaluation
• Right Documentation

29. Nursing Management
• Nursing : An Art and a
Science
• The Nursing Process
1. Assessment
2. Nursing Diagnosis
3. Planning
4. Interventions
5. Evaluation

30. ASSESSMENT
• History
- chronic conditions
- Drug Use
- Allergies
- level of education
- level of understanding of Disease
and therapy

31. - Social Supports
- Financial Supports
- Pattern of Health Care
- Physical Assessment
1. weight
2. age
3. Physical Parameters r/t
disease or drug effects

32. NURSING DIAGNOSIS
• IT MAY BE:
1. two part
2. three part
• Should be based on NANDA

33. PLANNING
• Should be SMART
• Can be short term or long
term

34. INTERVENTIONS
• 7 points to Proper Drug Administration
1. Drug
2. Storage
3. Route
4. Dosage
5. Preparation
6. Timing
7. recording

35. Comfort measures
• Placebo effect
• Managing adverse effects
• Lifestyle adjustment
• Patient and Family Education

36. KEY ELEMENTS TO PATIENT
EDUCATION
• Name, Dose and action of Drug
• Timing of Administration
• Special Storage and preparation
instructions
• Special comfort or safety measures
• Safety measures
• Specific points about drug toxicity
• Special warnings about drug
discontinuation

37. EVALUATION
• The evaluation is an
integral part in the
nursing process.
• The effectivity of the drug
therapy is determined
through evaluation.

38. Dosage Calculations

39. Drug Order
• Elements of a Drug Order
• Abbreviations
• Interpreting Drug Orders

40. DOSAGE CALCULATIONS
• Measuring Systems
- Metric System
- Apothecary System
- Household system

41. Converting between Systems
• Ratio and proportion

42. Calculating Dosage
• Oral Drugs
• Parenteral Drugs
• Intravenous solutions
• Pediatric considerations

43. GENERAL FORMULA
Dosage X quantity
stock

44. ORAL DRUGS
• Amt of drug available = amt of drug prescribed
one tablet or capsule no. of tabs or caps

45. PARENTERAL DRUGS
Amt of drug available = amt of drug prescribed
volume available volume to administer

46. Intravenous Solution
Drops/min = mL of sol pres/hr x drops delivered / mL
60 minutes / 1 hour

47. 1. Clark's Rule for Infants or Children:
Clark’s rule is based upon the weight of
the child. To determine the proper dosage
for children, divide child’s weight in pounds
by 150 to get the correct fraction of adult
dose. Example: For a 50 pound child give
50/150 (or 1/3) of the adult dose.
Therefore, if the adult dose is 30 drops
taken 3 times per day, the child’s dose will
be 10 drops taken 3 times per day (not 30
drops taken 1 time per day!)
(Weight in pounds x (Adult dose)
150
(That's: Child's weight in pounds times adult dose divided
by 150)

48. 2. Fried's Rule for Infants and Children up to 1
to 2 Years:
(Age in Months) x (Adult Dose)
150
(That's: Child's age in months times adult
dose divided by 150)

49. 3. Young's Rule for Children from 1 year to
12 Years:
Young’s rule is based upon the age of the
child, regardless of its weight. It is a “rule of
the thumb” method for calculating the dose of
medicine to be administered to a child. The
child’s age divided by age plus 12 represents
the fraction of the adult dose suitable for the
child.
(Age in Years) x (Adult Dose)
Age + 12
(That's: Child's age in years times adult dose
divided by child's age plus 12)

50. Problems
• Change to equivalents within the system:
1. 100 mg = ______g
2. 1500 g = ______kg
3. 0.1 L = _______ mL
4. 500 mL = _______L

51. Convert to units in the
metric system
• 150 gr = _________ g
• ¼ gr = ________mg
• 45 min = ______mL
• 2 qt = ______L

52. Convert to units in the
household system
• 5 mL = __________tsp
• 30 mL = _________tbsp

53. Convert the weights in the
following problems
• A patient weighs 170 lb. What is the
patient’s weight in kilograms?
• A patient weighs 3200 g. What is the
patient’s weight in pounds?

54. • Robitussin cough syrup 225 mg PO is
ordered. The bottle reads: 600 mg in 1
ounce. How much cough syrup should be
given?

55. • A postoperative order is written for ¼ gr
codeine every 4 hours as needed for pain.
Each dose given will contain how many
milligrams of codeine?

56. Thank you for Listening!