1. Principles of Drugs

2. Testing of the new drugs before use
Not teratogenic ( causes birth defect)
Carcinogenic ( causes cancer)
Toxicity studies not harmful to body system.
It should specific in action and its mechanism of action understood as complitly as possible.
Optimal route of administration.

3. Phases of new drug developments (FDA)
Animal Trials
Phase 1: the drug is tested on healthy volunteers.
Phase 2: involves trials with human subjects who have the disease.
Phase 3: large number of patients receive drug to provide information about adverse effect.
Phase 4: post market surveillance.

4. Resources for Drug Information
Pharmacopedia
Official resource
US Pharmacopedia, British Pharmacopedia
Compendia
Non Official
American Formulary, Facts & Comparisons, USP Dispensing
Journals
Nursing 2005
AJN RN
Nursing Reference Books
Web sites

7. Pharmacokinetics
Absorption
Distribution
Metabolism
Excretion

8. Absorption: means the transfer of the drug from the external to the internal environment of the body.

10. Absorption Oral Preparations
Liquids, elixirs, syrups Fastest Suspension solutions ê Powders ê Capsules ê Tablets ê Coated tablets ê Enteric-coated tablets Slowest

11. Absorption Factors That Affect Absorption
Administration route of the drug
Food or fluids administered with the drug
Dosage formulation
Status of the absorptive surface
Rate of blood flow to the small intestine
Acidity of the stomach
Status of GI motility

12. Distribution
The transport of a drug in the body by the bloodstream to its site of action.
Protein-binding
Water soluble vs. fat soluble
Blood-brain barrier
Areas of rapid distribution: heart, liver, kidneys, brain
Areas of slow distribution: muscle, skin, fat

13. First-Pass Effect
The metabolism of a drug and its passage from the liver into the circulation.
A drug given via the oral route may be extensively metabolized by the liver before reaching the systemic circulation (high first-pass effect).
The same drug—given IV—bypasses the liver, preventing the first-pass effect from taking place, and more drug reaches the circulation.

14. Metabolism (also known as Biotransformation)
The biologic transformation of a drug into an inactive metabolite, a more soluble compound, or a more potent metabolite.
Liver (main organ)
Kidneys
Lungs
Plasma
Intestinal mucosa

15. Factors that decrease metabolism:
Cardiovascular dysfunction
Renal insufficiency
Starvation
Obstructive jaundice
Erythromycin or ketoconazole drug therapy

16. Factors that increase metabolism:
Barbiturates
Rifampin therapy
Delayed drug metabolism results in:
Accumulation of drugs
Prolonged action of the effects of the drugs

17. Excretion The elimination of drugs from the body Kidneys (main organ)
Liver
Bowel
Biliary excretion
Enterohepatic circulation

18. Half-Life
The time it takes for one half of the original amount of a drug in the body to be removed.
A measure of the rate at which drugs are removed from the body.

19. Pharmacodynamics Onset
The time it takes for the drug to elicit a therapeutic response
Peak
The time it takes for a drug to reach its maximum therapeutic response
Duration
The time a drug concentration is sufficient to elicit a therapeutic response

20. Pharmacodynamics Drug actions:
The cellular processes involved in the drug and cell interaction
Drug effect:
The physiologic reaction of the body to the drug

21. The receptor: are protein that may occur on the surface of the cell.
They have two important functions:
To bind the body own chemical messenger such as hormones and neurotransmitters.
To convert into signals that the cell can recognize and respond to.
Two important properties:
Specificity
Affinity

22. Agonists: the ability of drug to bind receptor (drug that produce response).
Antagonist: drug that blocks the action of antagonist. ( Naloxone).
Partial agonist: is a drug that is able to both stimulate and block at receptor

23. Principles of Drug and Dosage Administration
Drugs may have more than one indication, i.e. each may have more than one action depending upon dosage
Aspirin given in low doses to relieve pain & high doses to suppress inflammation (arthritis)
Drugs can be administered by different routes and dosage depends on route given.
Oral doses usually larger than injected doses and may be fatal if given by incorrect route
Certain IV drugs can cause local injury if intravenous line becomes extravasated.

24. Guidelines to help ensure correct administration
Read medication order carefully
Verify identity of patient with drug order.
Read medication label & verify
Drug itself
Amount of drug
Verify suitability for administration by intended route
Verify dosage calculations
Use special handling if drug requires
DO NOT ADMINISTER ANY DRUG IF YOU DO NOT UNDERSTAND THE REASON FOR ITS USE

25. Therapeutic Objective - To provide maximum benefit with minimum harm
Therapeutic Objective - To provide maximum benefit with minimum harm. **Must also be ready to respond to interaction between drug and patient (i.e., must be aware of drug REACTIONS and SIDE EFFECTS)**

26. Evaluating and Promoting Therapeutic Effects
Is the drug doing the right thing?
Must know rationale for treatment and the nature and time course of desired response
If do not have this then cannot make judgment of progress
If desired response do not occur then must act quickly.
Give alternative therapy
Even if patient gains beneficial responses, must be aware of what drug is supposed to do, because it still might end up badly
Nifedipine: given for hypertension & angina pectoris: when given to treat hypertension should monitor for reduction in blood pressure; if used for treatment of angina, need to monitor for reduction in chest pain.

27. Minimize Adverse Effects
Know patient history
Understand disease and treatment and what drug is supposed to do (again, do not give drug blindly!!!)
Identify high risk patient
Educate patient
Know adverse effects of drug and educate patient.
Know drug interactions with other medications
This is important part of patient history

28. Promote Compliance Drugs must be taken correctly Wrong dose
Wrong route
Wrong time
Educate patients to how to self medicate with specific instructions
If elderly must also give instructions to another responsible party.
Implement Non-drug measures to enhance drug effects
Breathing exercises, biofeedback, emotional support, exercise, physical therapy, rest, weight reduction, stop smoking, and sodium restriction (must evaluate individual patient for specific needs)

29. Patient Education
Drug name and therapeutic category (penicillin & antibiotic)- give generic name and trade name
Dosage size
Dosing schedule (PRN not fixed)-what to do if missed?
Route and technique of administration.
Expected therapeutic response and when it should develop
Non drug measures to enhance therapeutic responses
Duration of treatment
Method of drug storage

30. Pharmacology and the Nursing Process
Nursing Process 1) assessment 2) nursing diagnosis 3) planning- individual for each patient 4) implementation- some collaborative with physician and others are independent 5) evaluation- degree to which drug therapy is successful

31. Pre-administration Assessment
Establishes the baseline data needed to tailor drug therapy to the individual patient: maximizes benefits and minimizes harmful effects
Collection of baseline data needed to evaluate therapeutic responses- beneficial: know the symptoms so you know what baseline data to collect
blood chemistry profiles
Blood pressure
Organ enzyme levels (heart, liver, kidney,…)

32. Collection of baseline data needed to evaluate adverse effects:
Even without baseline data, adverse affects may be obvious (hair loss, pain, vomiting, insomnia)
Less obvious are organ functions (liver, kidney,)
Identification of high risk patients:
Depends on symptoms and drug chosen (if patient has kidney dysfunction and drug is eliminated primarily through kidney, then drug will accumulate and may be toxic)
Impaired kidney & liver

33. Assessment of patient’s capacity for self-care-
Must be willing and able to administer drugs in correct dosage and at correct time
Evaluate patient intelligence
Patient physical capacity to self administer
Mental illness (will they take drug?)
Financial ability to pay for and get drug
Religious beliefs concerning drugs and medications
Understanding of patient that drug is needed in prescribed amount (even when they feel better)
Assess and discuss with physician

34. Nursing Diagnoses and Analysis of Drug:
Judge appropriateness of prescribed regime
Identify potential health problems that drug might cause
Determine patient’s capacity for self care
Nurse can question appropriateness of drug!
must know action of drug
contraindications of drug
Potential benefits vs adverse reactions to drug
Patient history
Potential interactions of drug with other medications

35. Planning
Define goals: goal of drug therapy is to provide maximum benefit with minimal harm.
Establish Priorities: requires knowledge of drug put together with patient’s unique history. 1st priority is life threatening conditions and reactions that cause acute discomfort that ends in long-term harm
Identifying interventions:
Drug administration
To enhance drug effectiveness
To minimize adverse effects and interactions
Patient education
Establish criteria for evaluation: is drug working?

36. Implementation of care plan
Drug administration
Patient education
Interventions to promote therapeutic effects
Interventions to minimize adverse effects
Evaluation
Therapeutic responses
Adverse drug reactions and interactions
Compliance to regimen
Satisfactions with treatment
How frequent do you evaluate??
Depends on ….. ???
Evaluation by lab tests- baseline data vs current data